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This article describes OSE's use of the Discourse software.
For a detailed guide to updating our Discourse server, see [[Discourse/Updating]].
For a detailed guide on how we installed Discourse in 2020 on our CentOS 7 server, see [[Discourse/Install]].
=Official Discourse Documentation=
Discourse doesn't have any official documentation outside of their [https://docs.discourse.org/ API documentation].
It appears that this is intentional to make Discourse admins' lives difficult as a way to increase revenue. See [[#Strategic Open Source]] for more info.
=TODO=
=TODO=


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# <s>iptables rules that prevent the discourse app from being able to initiate calls to the Internet (it should *only* be able to *respond* to queries) as we do for our apache backend by blocking non-established traffic from going through the OUTPUT table by the apache uid</s>
# <s>iptables rules that prevent the discourse app from being able to initiate calls to the Internet (it should *only* be able to *respond* to queries) as we do for our apache backend by blocking non-established traffic from going through the OUTPUT table by the apache uid</s>
## TODO: test an upgrade after this is done as well.
## <s>test an upgrade after this is done as well.</s>
# <s>OWASP CORS rules to prevent sqli/XSS/etc attacks as we do in apache</s>
# <s>OWASP CORS rules to prevent sqli/XSS/etc attacks as we do in apache</s>
## <s>update the install-nginx script so that it compiles nginx with mod_security (and probably downloads the OWASP CRS as well) https://github.com/discourse/discourse_docker/blob/416467f6ead98f82342e8a926dc6e06f36dfbd56/image/base/install-nginx</s>
## <s>update the install-nginx script so that it compiles nginx with mod_security (and probably downloads the OWASP CRS as well) https://github.com/discourse/discourse_docker/blob/416467f6ead98f82342e8a926dc6e06f36dfbd56/image/base/install-nginx</s>
## <s>add a new templates/web.modsecurity.yml file that updates the /etc/nginx/conf.d/discourse.conf file to enable mod_security (and add some blacklisted rules as-needed), similar to the existing web.socketed.template.yml file https://github.com/discourse/discourse_docker/blob/416467f6ead98f82342e8a926dc6e06f36dfbd56/templates/web.socketed.template.yml</s>
## <s>add a new templates/web.modsecurity.yml file that updates the /etc/nginx/conf.d/discourse.conf file to enable mod_security (and add some blacklisted rules as-needed), similar to the existing web.socketed.template.yml file https://github.com/discourse/discourse_docker/blob/416467f6ead98f82342e8a926dc6e06f36dfbd56/templates/web.socketed.template.yml</s>
# Minimum/hardened permissions of the /var/discourse dir
# <s>iptables on docker container instead of total internet blocking so the docker container can actually update its own OS packages?</s>
# <s>iptables on docker container instead of total internet blocking so the docker container can actually update its own OS packages?</s>
## <s>TODO: document update to `launcher` script's run_start() function's final `docker run` command to add the argument '--add-cap=NET_ADMIN' so the docker container root's user has permission to modify iptables rules.</s>
## <s>TODO: document update to `launcher` script's run_start() function's final `docker run` command to add the argument '--add-cap=NET_ADMIN' so the docker container root's user has permission to modify iptables rules.</s>
# Varnish cache https://meta.discourse.org/t/does-discourse-container-use-unattended-upgrades/136296
# <s>Fix unattended-upgrade https://meta.discourse.org/t/does-discourse-container-use-unattended-upgrades/136296</s>
# Fix unattended-upgrade https://meta.discourse.org/t/does-discourse-container-use-unattended-upgrades/136296
# <s>Test/document Discourse upgrade process</s>
# Test/document Discourse upgrade process
# <s>Test/document backup & restore process</s>
# Test/document backup & restore process
# <s>Stable cron job for docker image cleanup to prevent disk-fill</s>
# <s>Stable cron job for docker image cleanup to prevent disk-fill</s>
# Varnish cache https://meta.discourse.org/t/discourse-purge-cache-method-on-content-changes/132917
# Minimum/hardened permissions of the /var/discourse dir https://meta.discourse.org/t/minimum-hardened-file-permissions/148974


=Useful Commands=
=Useful Commands=
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# Takes 5-20 minutes to run, and it may break. Test on staging first.
# Takes 5-20 minutes to run, and it may break. Test on staging first.
/var/discourse/launcher rebuild discourse_ose
/var/discourse/launcher rebuild discourse_ose
# "enter" a docker image to inspect/debug/troubleshoot the image itself
[root@osestaging1 ~]# docker image ls
REPOSITORY                      TAG                IMAGE ID            CREATED            SIZE
local_discourse/discourse_ose  latest              b4d3feecf9e1        5 days ago          2.62GB
discourse_ose                  latest              2ea22070a06d        2 weeks ago        2.33GB
[root@osestaging1 ~]# docker run --rm -it --entrypoint /bin/bash 2ea22070a06d
root@00841db59cd7:/#


# get capabilities of discourse docker container
# get capabilities of discourse docker container
id=`docker inspect --format="{{.Id}}" discourse_ose`
id=`docker inspect --format="{{.Id}}" discourse_ose`
grep -E 'CapAdd|CapDrop|Capabilities' /var/lib/docker/containers/$id/hostconfig.json
grep -E 'CapAdd|CapDrop|Capabilities' /var/lib/docker/containers/$id/hostconfig.json
# tail "outer" nginx logs
tail -c0 -f /var/log/nginx/*log /var/log/nginx/discourse.opensourceecology.org/*log
# monitor varnish for discourse-specific queries only
varnishlog -q "ReqHeader eq 'Host: discourse.opensourceecology.org'"
# tail "inner" discourse logs (run this on the docker host, not inside the container)
tail -c0 -f /var/discourse/shared/standalone/log/rails/*log /var/discourse/shared/standalone/log/var-log/redis/current /var/discourse/shared/standalone/log/var-log/postgres/current /var/discourse/shared/standalone/log/var-log/nginx/*log
</pre>
</pre>


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</pre>
</pre>


==Unable to Connect==
==Web Server Issues==
 
This section will cover troubleshooting issues with Nginx, Varnish, etc.
 
Below will be just a list of error messages posted here primarily for the purpose of catching search queries on this wiki and directing them to this text:
 
To troubleshoot Discourse web server issues, this is a reminder: remember that there are two distinct nginx servers:
 
# nginx running on the server (docker host)
# nginx running _inside_ the discourse container running on the server
 
Don't forget to troubleshoot both!
 
<pre>
user@ose:~$ curl -kI https://discourse.opensourceecology.org/
HTTP/1.1 502 Bad Gateway
Server: nginx
Date: Mon, 30 Mar 2020 09:03:23 GMT
Content-Type: text/html
Content-Length: 150
Connection: keep-alive
 
user@ose:~$
</pre>
 
===502 Bad Gateway===
 
Relevant error messages:
 
* cURL
 
<pre>
Failed to connect to discourse.opensourceecology.org port 80: Connection refused
</pre>
 
===Unable to Connect===


Relevant error messages:
Relevant error messages:
Line 136: Line 200:
</pre>
</pre>


This is because literally nothing is responding on the ip address and port. There's actually two nginx processes to debug:
This is because literally nothing is responding on the ip address and port.
 
# nginx running on the server
# nginx running on the discourse container running on the server
 
Make sure you debug both!


==`git pull` fail==
==`git pull` fail==
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The easiest action is to just move the locally modified files out of the way, do a clean `<code>git pull</code>`, make note a diff of the changes, and re-apply the local changes by re-visiting the relevant section of install guide. For detailed instructions on this process, see the "Updating Discourse" [[#Step 3: Update git]] section.
The easiest action is to just move the locally modified files out of the way, do a clean `<code>git pull</code>`, make note a diff of the changes, and re-apply the local changes by re-visiting the relevant section of install guide. For detailed instructions on this process, see the "Updating Discourse" [[#Step 3: Update git]] section.


=2019-11 Install Guide=
==Removal In Progress==


In 2019-11, I ([[User:Maltfield|Michael Altfield]]) tested an install of Discourse on the [[OSE Staging Server]]. I documented the install steps here so they could be exactly reproduced on production
You may get an error when attempting to rebuild the Discourse docker container because an old docker container is stuck in a "Removal In Progress" state. For example:
 
==Install Prereqs==
 
First we have to install docker. The version in the yum repos (1.13.1) was too old to be supported by Discourse (which states it requires a minimum of 17.03.1).
 
Note that the install procedure recommended by Docker and Discourse for Docker is a curl piped to shell. This should never, ever, ever be done. The safe procedure is to manually add the gpg key and repo to the server as get.docker.org script should do -- assuming it were not modified in transit. Note that Docker does *not* cryptographically sign their install script in any way, and it therefore cannot be safely validated.
 
The gpg key itself is available at the following URL from docker.com
 
* https://download.docker.com/linux/centos/gpg
 
Please do your due diligence to validate that this gpg key is the official key and was not manipulated in-transit by Mallory. Unfortunately, at the time of writing, this is non-trivial since there's no signatures on the key, the key is not uploaded to any public keyservers, the docker team doesn't have a keybase account, etc. I submitted a feature request to the docker team's 'for-linux' repo asking them to at least upload this gpg key to the keys.openpgp.org keyserver on 2019-11-12 <ref>https://github.com/docker/for-linux/issues/849</ref>
 
After installing the docker gpg file to '<code>/etc/pki/rpm-gpg/docker.gpg</code>', execute the following commands as root to install docker:


<pre>
<pre>
# first, install the (ASCII-armored) docker gpg key to /etc/pki/rpm-gpg/docker.gpg
[root@osestaging1 discourse]# time /var/discourse/launcher rebuild discourse_ose
cp docker.gpg /etc/pki/rpm-gpg/docker.gpg
...
chown root:root /etc/pki/rpm-gpg/docker.gpg
169:M 23 Mar 2020 10:19:33.054 # Redis is now ready to exit, bye bye...
chmod 0644 /etc/pki/rpm-gpg/docker.gpg
2020-03-23 10:19:33.127 UTC [52] LOG: database system is shut down
 
sha256:6e6c81a3529175c1aa8e3391599499704f3abb9833ca3e943cf1b5443da4f47c
# and install the repo
fbf51479947c537d2247bf38bd0ca2f1cb96257dbbf86e93038e6a19f2bab5d6
cat > /etc/yum.repos.d/docker-ce.repo  <<'EOF'
Removing old container
[docker-ce-stable]
+ /bin/docker rm discourse_ose
name=Docker CE Stable - $basearch
Error response from daemon: container 12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8: driver "overlay2" failed to remove root filesystem: unlinkat /var/lib/docker/overlay2/99f609ae22d509152fd6db0120ba111c4d892b153d41d2e720790c864d5d678a/merged: device or resource busy
baseurl=https://download.docker.com/linux/centos/7/$basearch/stable
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/docker.gpg
EOF
 
# finally, install docker from the repos
yum install docker-ce
</pre>
 
Now execute the following commands as root to make docker start on system boot & start it up.
 
<pre>
systemctl enable docker.service
systemctl start docker.service
</pre>
 
==Install Discourse==
 
In this step we will configure & install the Discourse docker container and all its components
 
===Clone Repo===
 
From the [https://github.com/discourse/discourse/blob/master/docs/INSTALL-cloud.md Disourse Install Guide], checkout the github repo as root to /var/discourse. You'll want to validate that this wasn't modified in transit; there are no cryptographic signatures to validate authenticity of the repo's contents here. A huge failing on Discourse's part (but, again, Discourse's sec is rotten from its foundation in Docker; see above).
 
Execute the following as root to populate the '<code>/var/discourse/</code>' directory:
 
<pre>
sudo -s
git clone https://github.com/discourse/discourse_docker.git /var/discourse
cd /var/discourse
</pre>
 
===Create container yaml===
 
Now, the next step of the official Discourse '<code>INSTALL-cloud</code>' guide is to use the `<code>./discourse-setup</code>` script, but--at the time of writing--that script doesn't support building a config for servers that have an MTA running on the server without auth (ie: most linux servers on the net, whose MTA isn't accessible over the internet and instead just handle traffic over 127.0.0.1 and don't require auth--like our server is setup).
 
But we need to run this `<code>./discourse-setup</code>` script once just to generate a template '<code>app.yml</code>' config file before proceeding. When it asks you for a hostname, enter '<code>discourse.example.com</code>', which will cause it to fail but generate the '<code>containers/app.yml</code>' file that we need so we can proceed with manual install.
 
Execute the commands shown in the example below as root, inputting to the prompts matching what is shown:
 
<pre>
[root@osestaging1 discourse]# ls containers/
[root@osestaging1 discourse]#
[root@osestaging1 discourse]# ./discourse-setup
which: no docker.io in (/sbin:/bin:/usr/sbin:/usr/bin)
which: no docker.io in (/sbin:/bin:/usr/sbin:/usr/bin)
./discourse-setup: line 275: netstat: command not found
./discourse-setup: line 275: netstat: command not found
Ports 80 and 443 are free for use
‘samples/standalone.yml’ -> ‘containers/app.yml’
Found 1GB of memory and 1 physical CPU cores
setting db_shared_buffers = 128MB
setting UNICORN_WORKERS = 2
containers/app.yml memory parameters updated.
 
Hostname for your Discourse? [discourse.example.com]: discourse.example.com
 
Checking your domain name . . .
WARNING:: This server does not appear to be accessible at discourse.example.com:443.
 
A connection to http://discourse.example.com (port 80) also fails.
 
This suggests that discourse.example.com resolves to the wrong IP address
or that traffic is not being routed to your server.
 
Google: "open ports YOUR CLOUD SERVICE" for information for resolving this problem.
 
If you want to proceed anyway, you will need to
edit the containers/app.yml file manually.
[root@osestaging1 discourse]#
</pre>
 
Verify the change from the previous commands by confirming the existence of the '<code>containers/app.yml</code>' file.
 
<pre>
[root@osestaging1 discourse]# ls containers/
app.yml
[root@osestaging1 discourse]#
 
</pre>
 
The default name of the Discourse docker container is '<code>app</code>'. Let's rename that to '<code>discourse_ose</code>'.
 
Execute the following command as root to update th container's yaml file name:
 
<pre>
mv containers/app.yml containers/discourse_ose.yml
</pre>
 
Verify the change from the previous command by confirming that the file is now named '<code>discourse_ose.yml</code>'
 
<pre>
[root@osestaging1 discourse]# ls containers/
discourse_ose.yml
[root@osestaging1 discourse]#
</pre>
 
===SMTP===
 
The Discourse install script doesn't support the very simple config of an smtp server running on localhost:25 without auth. That is to say, Discourse doesn't support the default postfix config for RHEL/CentOS and most web servers on the net..
 
We have to manually edit the /var/discourse/containers/discourse_ose.yml
 
Note that 'localhost' resolves to the IP Address of the container created by docker when referenced from within the context of Discourse, but our smtp server is running on the host server. Therefore, we cannot use 'localhost' for the DISCOURSE_SMTP_ADDRESS. Instead, we use the IP Address of the host server's docker0 interface. In this case, it's 172.17.0.1, and that can be verified via the output of `ip address show dev docker0` run on the host where docker is installed (in this case, osestaging1).
 
First, let's comment-out any existing SMTP-related environment variables defined in the yml file.
 
Execute the following command as root to comment-out the SMTP-related lines in the yaml file:
 
<pre>
sed --in-place=.`date "+%Y%m%d_%H%M%S"` 's%^\([^#]*\)\(DISCOURSE_SMTP.*\)$%\1#\2%' /var/discourse/containers/discourse_ose.yml
</pre>
 
Now execute the following commands as root to add our SMTP settings to the '<code>env:</code>' section:
 
<pre>
grep 'DISCOURSE_SMTP_ADDRESS: 172.17.0.1' /var/discourse/containers/discourse_ose.yml || sed --in-place=.`date "+%Y%m%d_%H%M%S"` 's%^env:$%env:\n  DISCOURSE_SMTP_ADDRESS: 172.17.0.1 # this is the IP Address of the host server on the docker0 interface\n  DISCOURSE_SMTP_PORT: 25\n  DISCOURSE_SMTP_AUTHENTICATION: none\n  DISCOURSE_SMTP_OPENSSL_VERIFY_MODE: none\n  DISCOURSE_SMTP_ENABLE_START_TLS: false\n%' /var/discourse/containers/discourse_ose.yml
</pre>
 
Verify the previous two changes by confirming that your '<code>discourse_ose.yml</code>' config file now looks something like this. Note the addition of the '<code>DISCOURSE_SMTP_*</code>' lines immediately under the '<code>env:</code>' block and that the following '<code>DISCOURSE_SMTP_*</code>' lines are commented-out.
 
<pre>
[root@osestaging1 discourse]# grep -C1 'DISCOURSE_SMTP' /var/discourse/containers/discourse_ose.yml
env:
  DISCOURSE_SMTP_ADDRESS: 172.17.0.1 # this is the IP Address of the host server on the docker0 interface
  DISCOURSE_SMTP_PORT: 25
  DISCOURSE_SMTP_AUTHENTICATION: none
  DISCOURSE_SMTP_OPENSSL_VERIFY_MODE: none
  DISCOURSE_SMTP_ENABLE_START_TLS: false


--
starting up existing container
  # WARNING the char '#' in SMTP password can cause problems!
+ /bin/docker start discourse_ose
  #DISCOURSE_SMTP_ADDRESS: smtp.example.com
Error response from daemon: container is marked for removal and cannot be started
  #DISCOURSE_SMTP_PORT: 587
Error: failed to start containers: discourse_ose
  #DISCOURSE_SMTP_USER_NAME: user@example.com
  #DISCOURSE_SMTP_PASSWORD: pa$$word
  #DISCOURSE_SMTP_ENABLE_START_TLS: true          # (optional, default true)


real    8m39.585s
user    0m1.764s
sys    0m1.684s
[root@osestaging1 discourse]#  
[root@osestaging1 discourse]#  
</pre>
</pre>


Also note that you will need to the postfix configuration (<code>/etc/postfix/main.cf</code>) to bind on the docker0 interface, change the '<code>mynetworks_style</code>' from '<code>host</code>' to nothing (comment it out), and add the docker0 subnet to the '<code>mynetworks</code>' list to auth the Discourse docker client to be able to send mail through the smtp server.
Restarting docker _may_ help you to manually delete the docker container. Or not
 
Execute the following command as root to update the postfix config:


<pre>
<pre>
grep 'mynetworks = 127.0.0.0/8, 172.17.0.0/16' /etc/postfix/main.cf || sed --in-place=.`date "+%Y%m%d_%H%M%S"` 's%^mynetworks_style = host$%#mynetworks_style = host\nmynetworks = 127.0.0.0/8, 172.17.0.0/16%' /etc/postfix/main.cf
[root@osestaging1 containers]# docker ps -a
CONTAINER ID        IMAGE              COMMAND            CREATED            STATUS                PORTS              NAMES
12bb1e40517b        4d92ff0b76a7        "/sbin/boot"        6 days ago          Removal In Progress                      discourse_ose
[root@osestaging1 containers]# systemctl restart docker
[root@osestaging1 containers]# docker ps -a
CONTAINER ID        IMAGE              COMMAND            CREATED            STATUS              PORTS              NAMES
12bb1e40517b        4d92ff0b76a7        "/sbin/boot"        6 days ago          Dead                                    discourse_ose
[root@osestaging1 containers]# docker rm 12bb1e40517b
Error response from daemon: container 12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8: driver "overlay2" failed to remove root filesystem: unlinkat /var/lib/docker/overlay2/99f609ae22d509152fd6db0120ba111c4d892b153d41d2e720790c864d5d678a/merged: device or resource busy
[root@osestaging1 containers]# docker ps -a
CONTAINER ID        IMAGE              COMMAND            CREATED            STATUS                PORTS              NAMES
12bb1e40517b        4d92ff0b76a7        "/sbin/boot"        6 days ago          Removal In Progress                      discourse_ose
[root@osestaging1 containers]#
</pre>
</pre>


Verify the change above by confirming that your postfix '<code>main.cf</code>' file now looks something like this. Note that the '<code>myhost_style</code>' lines are all commented-out and that the '<code>mynetworks</code>' line now includes '<code>172.17.0.1</code>'.
This issue coincides with the following error being written to the systemd journal log


<pre>
<pre>
root@osestaging1 discourse]# grep -E 'mynetworks|interfaces' /etc/postfix/main.cf
Mar 23 10:44:55 osestaging1 dockerd[16920]: time="2020-03-23T10:44:55.578997874Z" level=error msg="Error removing mounted layer 12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8: unlinkat /var/lib/docker/overlay2/99f609ae22d509152fd6db0120ba111c4d892b153d41d2e720790c864d5d678a/merged: device or resource busy"
# The inet_interfaces parameter specifies the network interface
Mar 23 10:44:55 osestaging1 dockerd[16920]: time="2020-03-23T10:44:55.579614708Z" level=error msg="Handler for DELETE /v1.40/containers/12bb1e40517b returned error: container 12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8: driver \"overlay2\" failed to remove root filesystem: unlinkat /var/lib/docker/overlay2/99f609ae22d509152fd6db0120ba111c4d892b153d41d2e720790c864d5d678a/merged: device or resource busy"
# the software claims all active interfaces on the machine. The
# See also the proxy_interfaces parameter, for network addresses that
#inet_interfaces = all
#inet_interfaces = $myhostname
#inet_interfaces = $myhostname, localhost
#inet_interfaces = localhost
inet_interfaces = 127.0.0.1, 172.17.0.1
# The proxy_interfaces parameter specifies the network interface
# the address list specified with the inet_interfaces parameter.
#proxy_interfaces =
#proxy_interfaces = 1.2.3.4
# receives mail on (see the inet_interfaces parameter).
# to $mydestination, $inet_interfaces or $proxy_interfaces.
# ${proxy,inet}_interfaces, while $local_recipient_maps is non-empty
# The mynetworks parameter specifies the list of "trusted" SMTP
# By default (mynetworks_style = subnet), Postfix "trusts" SMTP
# On Linux, this does works correctly only with interfaces specified
# Specify "mynetworks_style = class" when Postfix should "trust" SMTP
# mynetworks list by hand, as described below.
# Specify "mynetworks_style = host" when Postfix should "trust"
#mynetworks_style = class
#mynetworks_style = subnet
#mynetworks_style = host
# Alternatively, you can specify the mynetworks list by hand, in
# which case Postfix ignores the mynetworks_style setting.
#mynetworks = 168.100.189.0/28, 127.0.0.0/8
#mynetworks = $config_directory/mynetworks
#mynetworks = hash:/etc/postfix/network_table
mynetworks = 127.0.0.0/8, 172.17.0.0/16
# - from "trusted" clients (IP address matches $mynetworks) to any destination,
# - destinations that match $inet_interfaces or $proxy_interfaces,
# unknown@[$inet_interfaces] or unknown@[$proxy_interfaces] is returned
[root@osestaging1 discourse]#
</pre>
</pre>
 
===Other container env vars===
A fix is to stop docker, force remove the problem container's directory, and start docker again. '''It would be wise to make a backup before attempting to proceed with this, just in-case you permanently delete the wrong container's directory!'''
 
Now we will update the container's yaml file with the necessary environment variables.
 
Execute the following commands as root to set the DISCOURSE_DEVELOPER_EMAILS variable (and comment-out the existing one):


<pre>
<pre>
sed --in-place=.`date "+%Y%m%d_%H%M%S"` 's%^\([^#]*\)\(DISCOURSE_DEVELOPER_EMAILS.*\)$%\1#\2%' /var/discourse/containers/discourse_ose.yml
[root@osestaging1 containers]# docker ps -a
grep '^\s*DISCOURSE_DEVELOPER_EMAILS:' /var/discourse/containers/discourse_ose.yml || sed --in-place=.`date "+%Y%m%d_%H%M%S"` 's%^env:$%env:\n  DISCOURSE_DEVELOPER_EMAILS: 'discourse@opensourceecology.org,ops@opensourceecology.org,marcin@opensourceecology.org,michael@opensourceecology.org'\n\n%' /var/discourse/containers/discourse_ose.yml
CONTAINER ID        IMAGE              COMMAND            CREATED            STATUS                PORTS              NAMES
12bb1e40517b        4d92ff0b76a7        "/sbin/boot"        6 days ago          Removal In Progress                      discourse_ose
[root@osestaging1 containers]# docker ps -a --no-trunc
CONTAINER ID                                                      IMAGE                                                                    COMMAND            CREATED            STATUS                PORTS              NAMES
12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8  sha256:4d92ff0b76a725a5252fce8567e961fc01eebe68c2b34d1abc9c94cae041597e  "/sbin/boot"       6 days ago          Removal In Progress                      discourse_ose
[root@osestaging1 containers]# systemctl stop docker
[root@osestaging1 containers]# rm -rf /var/lib/docker/containers/12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8
[root@osestaging1 containers]# systemctl start docker
[root@osestaging1 containers]# docker ps -a
CONTAINER ID        IMAGE              COMMAND            CREATED            STATUS              PORTS              NAMES
[root@osestaging1 containers]#
</pre>
</pre>


Execute the following commands as root to set the DISCOURSE_HOSTNAME variable (and comment-out the existing one):
=Installing Themes and Components=


<pre>
By design, our [[Web_server_configuration|web servers]] can only <em>respond</em> to requests; they cannot initiate requests. And [[Discourse/Install#iptables|Discourse is no different]].
sed --in-place=.`date "+%Y%m%d_%H%M%S"` 's%^\([^#]*\)\(DISCOURSE_HOSTNAME.*\)$%\1#\2%' /var/discourse/containers/discourse_ose.yml
grep "DISCOURSE_HOSTNAME: 'discourse.opensourceecology.org'" /var/discourse/containers/discourse_ose.yml || sed --in-place=.`date "+%Y%m%d_%H%M%S"` "s%^env:$%env:\n  DISCOURSE_HOSTNAME: 'discourse.opensourceecology.org'\n\n%" /var/discourse/containers/discourse_ose.yml
</pre>


Verify the previous two changes by confirming that your '<code>discourse_ose.yml</code>' config file now looks something like this. Note the addition of the '<code>DISCOURSE_HOSTNAME</code>' and '<code>DISCOURSE_DEVELOPER_EMAILS</code>' lines immediately under the '<code>env:</code>' block and that the following '<code>DISCOURSE_HOSTNAME</code>' and '<code>DISCOURSE_DEVELOPER_EMAILS</code>' lines are commented-out.
This means that the usual route of installing themes and components in Discourse via the WUI (<code>Admin -> Customize -> Themes -> Install -> Popular -> Install</code>) won't work.


<pre>
<pre>
[root@osestaging1 discourse]# grep -C1 -E 'DISCOURSE_HOSTNAME|DISCOURSE_DEVELOPER_EMAILS' /var/discourse/containers/discourse_ose.yml
Error cloning git repository, access is denied or repository is not found
env:
  DISCOURSE_HOSTNAME: 'discourse@opensourceecology.org,ops@opensourceecology.org,marcin@opensourceecology.org,michael@opensourceecology.org'
 
 
  DISCOURSE_DEVELOPER_EMAILS: discourse.opensourceecology.org
 
--
  ## Required. Discourse will not work with a bare IP number.
  #DISCOURSE_HOSTNAME: 'discourse.example.com'
 
--
  ## on initial signup example 'user1@example.com,user2@example.com'
  #DISCOURSE_DEVELOPER_EMAILS: 'me@example.com,you@example.com'
 
[root@osestaging1 discourse]#
</pre>
</pre>


===Nginx socket===
==Step #1: Find repo==


Also, we already have nginx bound to port 443 as our ssl terminator, so the defaults in our container's yaml file will fail. Instead, we add the 'web.socketed.template.yml' file, remove the 'expose' block, and we'll setup nginx to proxy connections to the resulting discourse unix socket file <ref>https://meta.discourse.org/t/running-other-websites-on-the-same-machine-as-discourse/17247</ref>
To install a theme or theme component in our Discourse, first find its git repo. You can find many Discourse theme repos by listing all repos tagged with the topic '<code>discourse-theme</code>' or '<code>discourse-theme-component</code>' in the [https://github.com/discourse Discourse project on github].


Execute the following command as root to add the '<code>web.socketed.template.yml</code>' template to the list of templates in the '<code>discourse_ose.yml</code>' file.
* https://github.com/search?q=topic%3Adiscourse-theme+org%3Adiscourse+fork%3Atrue
* https://github.com/search?q=topic%3Adiscourse-theme-component+org%3Adiscourse+fork%3Atrue


<pre>
==Step #2: Download zip==
grep 'templates/web.socketed.template.yml' /var/discourse/containers/discourse_ose.yml || sed --in-place=.`date "+%Y%m%d_%H%M%S"` 's%^  - "templates/web.template.yml"$%  - "templates/web.template.yml"\n  - "templates/web.socketed.template.yml"%' /var/discourse/containers/discourse_ose.yml
</pre>


Verify the change from the above command by confirming that the container's yaml file now looks something like this. Note the addition of the '<code>web.socketed.template.yml</code>' line immediately under the '<code>templates:</code>' line.
[[File:202005_discourseInstallTheme1.jpg|left|600px]]


<pre>
For example, here's a link to the github repo for the Discourse "Classic Theme"
[root@osestaging1 discourse]# grep -C2 templates /var/discourse/containers/discourse_ose.yml
## visit http://www.yamllint.com/ to validate this file as needed


templates:
* https://github.com/discourse/discourse-classic
  - "templates/postgres.template.yml"
  - "templates/redis.template.yml"
  - "templates/web.template.yml"
  - "templates/web.socketed.template.yml"
  - "templates/web.ratelimited.template.yml"
## Uncomment these two lines if you wish to add Lets Encrypt (https)
  #- "templates/web.ssl.template.yml"
  #- "templates/web.letsencrypt.ssl.template.yml"


## which TCP/IP ports should this container expose?
From the theme's github repo page, download a zip of the repo by clicking <code>"Clone or download" -> "Download ZIP"</code>
[root@osestaging1 discourse]#
</pre>


And now execute the following command as root to comment-out the entire "expose" block and all its contents:
<br style="clear:both;" />
==Step #3: Upload zip==


<pre>
[[File:202005_discourseInstallTheme2.jpg|right|600px]]
perl -i".`date "+%Y%m%d_%H%M%S"`" -p0e 's%expose:\n  -([^\n]*)\n  -([^\n]*)%#expose:\n#  -\1\n#  -\2%gs' /var/discourse/containers/discourse_ose.yml
</pre>


Verify the change from the above command by confirming that the container yaml file now looks something like this. Note that the '<code>expose:</code>' line and all of its subsequent lines are commented-out:
Now, login to our Discourse site and navigate to <code>Admin -> Customize -> Themes</code>


<pre>
Click <code>Install</code>
[root@osestaging1 discourse]# grep -C4 expose /var/discourse/containers/discourse_ose.yml
## Uncomment these two lines if you wish to add Lets Encrypt (https)
  #- "templates/web.ssl.template.yml"
  #- "templates/web.letsencrypt.ssl.template.yml"


## which TCP/IP ports should this container expose?
<br style="clear:both;" />
## If you want Discourse to share a port with another webserver like Apache or nginx,
[[File:202005_discourseInstallTheme3.jpg|left|600px]]
## see https://meta.discourse.org/t/17247 for details
#expose:
#  - "80:80"   # http
#  - "443:443" # https


params:
In the JS modal "pop-up", choose <code>From your device</code>.
[root@osestaging1 discourse]#
</pre>


===Nginx mod_security===
Finally, click <code>Browse</code> and upload the <code>.zip</code> file downloaded above.


In our other sites hosted on this server, we have a nginx -> varnish -> apache architecture. While I'd like to mimic this architecture for all our sites, it's important to note a few things about Apache, Nginx, mod_security, and Discourse that elucidate why we shouldn't do that.
<br style="clear:both;" />


# There's a package in the yum repos for adding mod_security to apache. There is no package for adding mod_security to Nginx. Adding mod_security to Nginx requires compiling Nginx from source
=Looking Forward=
# Discourse is heavily tied to Nginx. It appears that nobody has ever run Discourse on Apache, and doing so would be non-trivial. Moreover, our custom Apache vhost config would likely break in future versions of Discourse <ref>https://meta.discourse.org/t/how-to-run-discourse-in-apache-vhost-not-nginx/133112/11</ref>
# Putting apache as a reverse proxy in-front of Discourse could add a significant performance issues because of the way Apache handles long polling, which the Discourse message bus uses <ref>https://meta.discourse.org/t/howto-setup-discourse-with-lets-encrypt-and-apache-ssl/46139</ref> <ref>https://stackoverflow.com/questions/14157515/will-apache-2s-mod-proxy-wait-and-occupy-a-worker-when-long-polling</ref> <ref>https://github.com/SamSaffron/message_bus</ref>
# The Discourse install process already compiles Nginx from source so that it can add the <code>brotli</code> module to nginx <ref>https://github.com/discourse/discourse_docker/blob/416467f6ead98f82342e8a926dc6e06f36dfbd56/image/base/install-nginx#L18</ref>


Therefore, I think it makes sense to cut apache out of the architecture for our Discourse install entirely. If we're already forced to compile nginx from source, we might as well just update their <code>install-nginx</code> script and configure mod_security in nginx instead of apache. Then our architecture becomes nginx -> varnish -> nginx.
This section will outline possible changes to be made to the Docker install/config in the future


First, execute the following commands as root to update the <code>install-nginx</code> script with the logic for installing the depends on our docker container and compiling nginx with mod_security.
==Moving DBs outside docker==


<pre>
It's worthwhile to consider moving the redis and postgresql components of Discourse outside of the docker container <ref>https://meta.discourse.org/t/performance-scaling-and-ha-requirements/60098/8</ref>
cd /var/discourse/image/base
cp install-nginx install-nginx.`date "+%Y%m%d_%H%M%S"`.orig
 
# add a block to checkout the the modsecurity nginx module just before downloading the nginx source
grep 'ModSecurity' install-nginx || sed -i 's%\(curl.*nginx\.org/download.*\)%# mod_security --maltfield\napt-get install -y libmodsecurity-dev modsecurity-crs\ncd /tmp\ngit clone --depth 1 https://github.com/SpiderLabs/ModSecurity-nginx.git\n\n\1%' install-nginx
 
# update the configure line to include the ModSecurity module checked-out above
sed -i '/ModSecurity/! s%^[^#]*./configure \(.*nginx.*\)%#./configure \1\n./configure \1 --add-module=/tmp/ModSecurity-nginx%' install-nginx
 
# add a line to cleanup section
grep 'rm -fr /tmp/ModSecurity-nginx' install-nginx || sed -i 's%\(rm -fr.*/tmp/nginx.*\)%rm -fr /tmp/ModSecurity-nginx\n\1%' install-nginx
</pre>
 
The above commands were carefully crafted to be idempotent and robust so that they will still work on future versions of the <code>install-nginx</code> script, but it's possible that they will break in the future. For reference, here is the resulting file.
 
Please verify the change from the above commands by confirming that your new file looks something like this. Note the addition of the '<code>mod-security</code>' block and the changed '<code>./configure</code>' line.
 
<pre>
[root@osestaging1 base]# cat /var/discourse/image/base/install-nginx
#!/bin/bash
set -e
VERSION=1.17.4
cd /tmp
 
apt install -y autoconf 
 
 
git clone https://github.com/bagder/libbrotli
cd libbrotli
./autogen.sh
./configure
make install
 
cd /tmp
 
 
# this is the reason we are compiling by hand...
git clone https://github.com/google/ngx_brotli.git
 
# mod_security --maltfield
apt-get install -y libmodsecurity-dev modsecurity-crs
cd /tmp
git clone --depth 1 https://github.com/SpiderLabs/ModSecurity-nginx.git
 
curl -O https://nginx.org/download/nginx-$VERSION.tar.gz
tar zxf nginx-$VERSION.tar.gz
cd nginx-$VERSION
 
# so we get nginx user and so on
apt install -y nginx libpcre3 libpcre3-dev zlib1g zlib1g-dev
# we don't want to accidentally upgrade nginx and undo our work
apt-mark hold nginx
 
# now ngx_brotli has brotli as a submodule
cd /tmp/ngx_brotli && git submodule update --init && cd /tmp/nginx-$VERSION
 
# ignoring depracations with -Wno-deprecated-declarations while we wait for this https://github.com/google/ngx_brotli/issues/39#issuecomment-254093378
#./configure --with-cc-opt='-g -O2 -fPIE -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wno-deprecated-declarations' --with-ld-opt='-Wl,-Bsymbolic-functions -fPIE -pie -Wl,-z,relro -Wl,-z,now' --prefix=/usr/share/nginx --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/run/nginx.pid --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-debug --with-pcre-jit --with-ipv6 --with-http_ssl_module --with-http_stub_status_module --with-http_realip_module --with-http_auth_request_module --with-http_addition_module --with-http_dav_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_v2_module --with-http_sub_module --with-stream --with-stream_ssl_module --with-mail --with-mail_ssl_module --with-threads --add-module=/tmp/ngx_brotli
./configure --with-cc-opt='-g -O2 -fPIE -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wno-deprecated-declarations' --with-ld-opt='-Wl,-Bsymbolic-functions -fPIE -pie -Wl,-z,relro -Wl,-z,now' --prefix=/usr/share/nginx --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/run/nginx.pid --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-debug --with-pcre-jit --with-ipv6 --with-http_ssl_module --with-http_stub_status_module --with-http_realip_module --with-http_auth_request_module --with-http_addition_module --with-http_dav_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_v2_module --with-http_sub_module --with-stream --with-stream_ssl_module --with-mail --with-mail_ssl_module --with-threads --add-module=/tmp/ngx_brotli --add-module=/tmp/ModSecurity-nginx
 
make install


mv /usr/share/nginx/sbin/nginx /usr/sbin
=Strategic Open Source=


cd /
[[File:202005_discourseStrategicOpenSource_PURGEtopic1.jpg|right|500px]]
rm -fr /tmp/ModSecurity-nginx
[[File:202005_discourseStrategicOpenSource_PURGEtopic2.jpg|right|600px]]
rm -fr /tmp/nginx
rm -fr /tmp/libbrotli
rm -fr /tmp/ngx_brotli
rm -fr /etc/nginx/modules-enabled/*
[root@osestaging1 base]#   
</pre>


Though unintuitive, Discourse's <code>launcher rebuild</code> script won't actually use these local files in <code>image/base/*</code>, including the <code>install-nginx</code> script modified above. To make sure that our Discourse docker container users a docker image with the nginx changes made above, we have to explicitly specify the image in the hard-coded <code>image</code> variable of the <code>launcher</code> script. This, sadly, is not documented anywhere by the Discourse project, and I only discovered this solution after much trial-and-error.
As of 2020, Discourse does appear to be the best solution to replace our deprecated [[Vanilla Forums]]. Unfortunately, it became clear over the course of its POC that the Discourse project is yet another example of [[Strategic Open Source]].


Execute the following commands as root to change the '<code>image</code>' variable in the Discourse '<code>launcher</code>' script.
While the code is open, Discourse does <em>not</em> have a open and collaborative culture.


<pre>
This escalated in May 2020 on meta.discourse.org after I ([[User:Maltfield|Michael Altfield]]) published my varnish config to a [https://meta.discourse.org/t/discourse-purge-cache-method-on-content-changes/132917 topic I was using to document integration of Discourse with Varnish]. The Discourse staff told me (again) that Discourse already has built-in caching.
# replace the line "image="discourse/base:<version>" with 'image="discourse_ose"'
grep 'discourse_ose' /var/discourse/launcher || sed --in-place=.`date "+%Y%m%d_%H%M%S"` '/base_image/! s%^\(\s*\)image=\(.*\)$%#\1image=\2\n\1image="discourse_ose"%' /var/discourse/launcher
</pre>


Verify the change from the above command by confirming that the launcher script now looks something like this. Note the commented-out '<code>image=</code>' line and its replacement below it.
I responded (again) asking where their built-in caching was documented. Then Jeff Atwood (co-founder of Discourse) stepped-in and linked me to their source code. Frustrated, I asked:


<pre>
<blockquote>
[root@osestaging1 discourse]# grep 'image=' /var/discourse/launcher
Michael Altfield: Serious question: Does the discourse team have a policy against writing documentation? Does the discourse project have any documentation-related policies at all?
user_run_image=""
</blockquote>
    user_run_image="$2"
#image="discourse/base:2.0.20200220-2221"
image="discourse_ose"
  run_image=`cat $config_file | $docker_path run $user_args --rm -i -a stdin -a stdout $image ruby -e \
    run_image=$user_run_image
    run_image="$local_discourse/$config"
  base_image=`cat $config_file | $docker_path run $user_args --rm -i -a stdin -a stdout $image ruby -e \
    image=$base_image
[root@osestaging1 discourse]#
</pre>


And now we must build the 'discourse_ose' docker image, which will execute the updated <code>install-nginx</code> script and then become available to the <code>launcher</code> script above. This image build will take 5 minutes to 1 hour to complete.
Atwood's response was to threaten to ban me


Execute the following command as root to build the custom Discourse docker image:
<blockquote>
Jeff Atwood: We do have a policy against people being rude to us. Would you like to explore that policy now?
</blockquote>


<pre>
I made clear how I appreciate and value anyone's contributions to an open-source code base and added "but code alone is not a substitute for documentation" before reiterating my question about their documentation polcies. Atwood's response was
time nice docker build --tag 'discourse_ose' /var/discourse/image/base/
</pre>


Next we create a new yaml template to update the relevant nginx configuration files when bootstrapping the environment.
<blockquote>
Atwood: ...We don't tend to spend time on that, as historically it is not a good use of our engineering budget. If you'd like to pay us...
</blockquote>


Execute the following commands as root to create the '<code>web.modsecurity.template.yml</code>' file.
Then, what really shocked me was that the entire thread was marked to be deleted in 14 days. Note that I had been using this thread as a place to document how to integrate Discourse with Varnish--something that as-yet hasn't been documented in such detail anywhere on the 'net.


<pre>
I added:
cat << EOF > /var/discourse/templates/web.modsecurity.template.yml
run:
  - exec:
    cmd:
      - sudo apt-get update
      - sudo apt-get install -y modsecurity-crs
      - cp /etc/modsecurity/modsecurity.conf-recommended /etc/modsecurity/modsecurity.conf
      - sed -i 's/SecRuleEngine DetectionOnly/SecRuleEngine On/' /etc/modsecurity/modsecurity.conf
      - sed -i 's^\(\s*\)[^#]*SecRequestBodyInMemoryLimit\(.*\)^\1#SecRequestBodyInMemoryLimit\2^' /etc/modsecurity/modsecurity.conf
      - sed -i '/nginx/! s%^\(\s*\)[^#]*SecAuditLog \(.*\)%#\1SecAuditLog \2\n\1SecAuditLog /var/log/nginx/modsec_audit.log%' /etc/modsecurity/modsecurity.conf


  - file:
<blockquote>
    path: /etc/nginx/conf.d/modsecurity.include
So I just noticed this:
    contents: |
        ################################################################################
        # File:    modsecurity.include
        # Version: 0.1
        # Purpose: Defines mod_security rules for the discourse vhost
        #          This should be included in the server{} blocks nginx vhosts.
        # Author:  Michael Altfield <michael@opensourceecology.org>
        # Created: 2019-11-12
        # Updated: 2019-11-12
        ################################################################################
        Include "/etc/modsecurity/modsecurity.conf"
       
        # OWASP Core Rule Set, installed from the 'modsecurity-crs' package in debian
        Include /etc/modsecurity/crs/crs-setup.conf
        Include /usr/share/modsecurity-crs/rules/*.conf


  - replace:
> This topic will be automatically deleted in 14 days.
    filename: "/etc/nginx/conf.d/discourse.conf"
    from: /server.+{/
    to: |
      server {
        modsecurity on;
        modsecurity_rules_file /etc/nginx/conf.d/modsecurity.include;


EOF
Please tell me this means this thead will become read-only and not deleted.
</pre>


Execute the following command as root to add the above-created template to our Discourse docker container yaml file's templates list:
I've gone through a lot of effort using this thread as a means to provide documentation to other users, and I want to ensure that it won't be deleted...
</blockquote>


<pre>
Their response? The immediately deleted the entire topic. But not before I made a backup ([[:File:202005_discourseStrategicOpenSource_PURGEtopic_full.gif|gif]], [[:File:202005_discourseStrategicOpenSource_PURGEtopic_full.pdf|pdf]]).
grep 'templates/web.modsecurity.template.yml' containers/discourse_ose.yml || sed -i 's%^\([^#].*templates/web.socketed.template.yml.*\)$%\1\n  - "templates/web.modsecurity.template.yml"%' containers/discourse_ose.yml
</pre>
 
Verify the change from the above command by confirming that the <code>containers/discourse_ose.yml</code> file looks something like this. Note the addition of the <code>templates/web.modsecurity.template.yml</code> line.
 
<pre>
[root@osestaging1 discourse]#  grep -A10 templates containers/discourse_ose.yml
templates:
  - "templates/postgres.template.yml"
  - "templates/redis.template.yml"
  - "templates/web.template.yml"
  - "templates/web.socketed.template.yml"
  - "templates/web.modsecurity.template.yml"
  - "templates/web.ratelimited.template.yml"
## Uncomment these two lines if you wish to add Lets Encrypt (https)
  #- "templates/web.ssl.template.yml"
  #- "templates/web.letsencrypt.ssl.template.yml"
 
## which TCP/IP ports should this container expose?
## If you want Discourse to share a port with another webserver like Apache or nginx,
## see https://meta.discourse.org/t/17247 for details
#expose:
#  - "80:80"  # http
#  - "443:443" # https


params:
This whole interaction made it clear to me that:
  db_default_text_search_config: "pg_catalog.english"
[root@osestaging1 discourse]#
</pre>


===iptables===
# Discourse has a toxic community that doesn't care about open collaboration
# Discourse intentionally doesn't document their product
# Discourse intentionally deletes user-submitted documentation
# I think that Discorse intentionally tries to make their product obscure and their users more helpless as a means to generate revenue


Discourse will run fine with its container having literally no internet access. This is because the communication in/out of the Discourse docker container is done via an nginx reverse proxy on the docker host through a unix socket file on the Discourse docker container.
<br style="clear:both;" />
 
However, the docker container is a whole OS on its own, including its own apt packages. Therefore, it's critical that the docker container running Discourse maintain security patches for its OS via Debian's unattended-upgrades.
 
* https://wiki.debian.org/UnattendedUpgrades
* https://github.com/discourse/discourse/blob/master/docs/INSTALL-cloud.md#post-install-maintenance
 
Therefore, rather than blocking all internet traffic from the Discourse container, it's better to use iptables on the docker host to setup a firewall similar to how we set it up on our other servers (blocking the web server from initiating OUTbound connections). Note that this is necessarily done <em>inside</em> the container so we can create OUTPUT rules that block on a per-user basis, which cannot be done from the docker host. This is critical to prevent nginx/ruby/etc from initiating outbound connections. Indeed, web servers should only be able to <em>respond</em> to requests.
 
Unfortunately, being root in the default Discourse docker container is actually not sufficient to edit iptables rules. You'll still get permission denied errors. To fix this, first we must add the <code>NET_ADMIN</code> capability to the Discourse docker container spawned by the <code>launcher</code> script. The most robust way to add the <code>NET_ADMIN</code> capability to the Discourse docker container is to update your container’s yaml file to include the necessary argument to the <code>docker run ... /sbin/boot</code> command via the <code>docker_args</code> yaml string:
 
Execute this as root to update the container's yaml file:
 
<pre>
grep 'NET_ADMIN' /var/discourse/containers/discourse_ose.yml || sed --in-place=.`date "+%Y%m%d_%H%M%S"` 's%^templates:$%docker_args: "--cap-add NET_ADMIN"\n\ntemplates:%' /var/discourse/containers/discourse_ose.yml
</pre>
 
Verify the change from the above command by confirming that your file now looks something like this. Note the addition of the 'docker_args:' line.
 
<pre>
[root@osestaging1 discourse]# grep -C2 'templates:' /var/discourse/containers/discourse_ose.yml
docker_args: "--cap-add NET_ADMIN"
 
templates:
  - "templates/web.socketed.template.yml"
  - "templates/web.modsecurity.template.yml"
[root@osestaging1 discourse]#
</pre>
 
The above change defined <code>--cap-add NET_ADMIN</code> as an extra argument to be passed to the <code>docker run ... /sbin/boot</code> command executed by <code>launcher</code> script's <code>run_start()</code> function via the <code>$user_args</code> variable:
 
* https://github.com/discourse/discourse_docker/blob/87fd7172af8f2848d5118fdebada646c5996821b/launcher#L631-L633
 
<pre>
run_start() {
...
    $docker_path run --shm-size=512m $links $attach_on_run $restart_policy "${env[@]}" "${labels[@]}" -h "$hostname"
        -e DOCKER_HOST_IP="$docker_ip" --name $config -t "${ports[@]}" $volumes $mac_address $user_args \
        $run_image $boot_command
 
  )
  exit 0
 
}
</pre>
 
Now we add a template for setting up iptables in the docker container's runit boot scripts.
 
<pre>
cat << EOF > /var/discourse/templates/iptables.template.yml
run:
  - file:
    path: /etc/runit/1.d/01-iptables
    chmod: "+x"
    contents: |
        #!/bin/bash
        ################################################################################
        # File:    /etc/runit/1.d/01-iptables
        # Version: 0.2
        # Purpose: installs & locks-down iptables
        # Author:  Michael Altfield <michael@opensourceecology.org>
        # Created: 2019-11-26
        # Updated: 2019-12-17
        ################################################################################
        sudo apt-get update
        sudo apt-get install -y iptables
        sudo iptables -A INPUT -i lo -j ACCEPT
        sudo iptables -A INPUT -s 127.0.0.1/32 -j DROP
        sudo iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
        sudo iptables -A INPUT -j DROP
        sudo iptables -A OUTPUT -s 127.0.0.1/32 -d 127.0.0.1/32 -j ACCEPT
        sudo iptables -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
        sudo iptables -A OUTPUT -m owner --uid-owner 0 -j ACCEPT
        sudo iptables -A OUTPUT -m owner --uid-owner 100 -j ACCEPT
        sudo iptables -A OUTPUT -j DROP
        sudo ip6tables -A INPUT -i lo -j ACCEPT
        sudo ip6tables -A INPUT -s ::1/128 -j DROP
        sudo ip6tables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
        sudo ip6tables -A INPUT -j DROP
        sudo ip6tables -A OUTPUT -s ::1/128 -d ::1/128 -j ACCEPT
        sudo ip6tables -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
        sudo ip6tables -A OUTPUT -m owner --uid-owner 0 -j ACCEPT
        sudo ip6tables -A OUTPUT -m owner --uid-owner 100 -j ACCEPT
        sudo ip6tables -A OUTPUT -j DROP
 
EOF
</pre>
 
And, finally, execute the following command as root to add the above-created template to our container yaml file's template list:
 
<pre>
grep 'templates/iptables.template.yml' /var/discourse/containers/discourse_ose.yml || sed --in-place=.`date "+%Y%m%d_%H%M%S"` 's%^templates:$%templates:\n  - "templates/iptables.template.yml"%' /var/discourse/containers/discourse_ose.yml
</pre>
 
Verify the change from the above command by confirming that your <code>containers/discourse_ose.yml</code> file looks something like this. Note the addition of the '<code>templates/iptables.template.yml</code>' line.
 
<pre>
[root@osestaging1 discourse]# grep -C2 'templates:' /var/discourse/containers/discourse_ose.yml
docker_args: "--cap-add NET_ADMIN"
 
templates:
  - "templates/iptables.template.yml"
  - "templates/web.socketed.template.yml"
[root@osestaging1 discourse]#
</pre>
 
==discourse.opensourcecology.org DNS==
 
Add 'discourse.opensourceecology.org' to the list of domain names defined for our VPN IP Address in /etc/hosts on the staging server.
 
In production, this will mean actually adding A & AAAA DNS entries for 'discourse' to point to our production server.
 
==Nginx Vhost Config==
 
Create the following nginx vhost config file to proxy connections sent to '<code>discourse.opensourceecology.org</code>' to the unix socket file created by Discourse. Note that this file exists on the docker server that runs the Discourse container, and it controls _that_ nginx server--which is distinct from the nginx server that runs _inside_ the Discourse docker container.
 
Execute the following commands as root to create the '<code>/etc/nginx/conf.d/discourse.opensourceecology.org.conf</code>' file.
 
<pre>
cat << EOF > /etc/nginx/conf.d/discourse.opensourceecology.org.conf
################################################################################
# File:    discourse.opensourceecology.org.conf
# Version: 0.1
# Purpose: Internet-listening web server for truncating https, basic DOS
#          protection, and passing to varnish cache (varnish then passes to
#          apache)
# Author:  Michael Altfield <michael@opensourceecology.org>
# Created: 2019-11-07
# Updated: 2019-11-07
################################################################################
 
# this whole site is a subdomain, so the below block for redirecting a naked
# domain does not apply here
#server {
#      # redirect the naked domain to 'www'
#      #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
#  #                  '$status $body_bytes_sent "$http_referer" '
#  #                  '"$http_user_agent" "$http_x_forwarded_for"';
#      #access_log /var/log/nginx/www.opensourceecology.org/access.log main;
#      #error_log /var/log/nginx/www.opensourceecology.org/error.log main;
#  include conf.d/secure.include;
#  include conf.d/ssl.opensourceecology.org.include;
#  listen 10.241.189.11:443;
#      server_name opensourceecology.org;
#      return 301 https://www.opensourceecology.org$uri;
#
#}
 
server {
 
access_log /var/log/nginx/discourse.opensourceecology.org/access.log main;
error_log /var/log/nginx/discourse.opensourceecology.org/error.log;
 
  include conf.d/secure.include;
  include conf.d/ssl.opensourceecology.org.include;
  #include conf.d/ssl.openbuildinginstitute.org.include;
 
  listen 10.241.189.11:443;
  #listen [2a01:4f8:172:209e::2]:443;
 
  server_name discourse.opensourceecology.org;
 
#############
# SITE_DOWN #
#############
# uncomment this block && restart nginx prior to apache work to display the
# "SITE DOWN" webpage for our clients
 
#      root /var/www/html/SITE_DOWN/htdocs/;
#  index index.html index.htm;
#
#      # force all requests to load exactly this page
#      location / {
#              try_files $uri /index.html;
#      }
 
###################
# SEND TO VARNISH #
###################
 
#  location / {
#      proxy_pass http://127.0.0.1:6081;
#      proxy_set_header X-Real-IP $remote_addr;
#      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
#      proxy_set_header X-Forwarded-Proto https;
#      proxy_set_header X-Forwarded-Port 443;
#      proxy_set_header Host $host;
#  }
 
##################
# SEND TO DOCKER #
##################
 
location / {
proxy_pass http://unix:/var/discourse/shared/standalone/nginx.http.sock:;
proxy_set_header Host $http_host;
proxy_http_version 1.1;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto https;
proxy_set_header X-Real-IP $remote_addr;
}
 
}
EOF
</pre>
 
==Varnish==
 
TODO: actually include varnish
 
* https://meta.discourse.org/t/discourse-purge-cache-method-on-content-changes/132917
 
==Backups==
 
Add this block to /root/backups/backup.sh (TODO: test this)
 
<pre>
#############
# DISCOURSE #
#############
 
# cleanup old backups
$NICE $RM -rf /var/discourse/shared/standalone/backups/default/*.tar.gz
time $NICE $DOCKER exec discourse_ose discourse backup
$NICE $MV /var/discourse/shared/standalone/backups/default/*.tar.gz "${backupDirPath}/${archiveDirName}/discourse_ose/"
 
...
 
#########
# FILES #
#########
 
# /var/discourse
echo -e "\tINFO: /var/discourse"
$MKDIR "${backupDirPath}/${archiveDirName}/discourse_ose"
time $NICE $TAR --exclude "/var/discourse/shared/standalone/postgres_data" --exclude "/var/discourse/shared/standalone/postgres_data/uploads" --exclude "/var/discourse/shared/standalone/backups" -czf ${backupDirPath}/${archiveDirName}/discourse_ose/discourse_ose.${stamp}.tar.gz /var/discourse/*
</pre>
 
==SSL Cert==
 
TODO: update the certbot cron script to add a Subject Alt Name for discourse.opensourceecology.org
 
==Import Vanilla Forums==
 
TODO: attempt to import our old forum's data into Discourse.
 
==Docker image cleanup cron==
 
A common pitfall when running docker in production is that the images build up over time, eventually filling the disk and breaking the server.
 
Execute the commands below as root to add a script and corresponding cron job & log dir for pruning docker images to prevent disk-fill:
 
<pre>
cat << EOF > /usr/local/bin/docker-purge.sh
#!/bin/bash
set -x
################################################################################
# Author:  Michael Altfield <michael at opensourceecology dot org>
# Created: 2020-03-08
# Updated: 2020-03-08
# Version: 0.1
# Purpose: Cleanup docker garbage to prevent disk fill issues
################################################################################
 
############
# SETTINGS #
############
 
NICE='/bin/nice'
DOCKER='/bin/docker'
DATE='/bin/date'
 
##########
# HEADER #
##########
 
stamp=`${DATE} -u +%Y%m%d_%H%M%S`
echo "================================================================================"
echo "INFO: Beginning docker pruning on ${stamp}"
 
###################
# DOCKER COMMANDS #
###################
 
# automatically clean unused container and images that are >= 4 weeks old
time ${NICE} ${DOCKER} container prune --force --filter until=672h
time ${NICE} ${DOCKER} image prune --force --all --filter until=672h
time ${NICE} ${DOCKER} system prune --force --all --filter until=672h
 
# exit cleanly
exit 0
EOF
chmod +x /usr/local/bin/docker-purge.sh
mkdir /var/log/docker
cat << EOF > /etc/cron.d/docker-prune
40 07 * * * root time /bin/nice /usr/local/bin/docker-purge.sh &>> /var/log/docker/prune.log
EOF
</pre>
 
==Start Discourse==
 
Execute the following command TODO
 
TODO
 
Congratulations! Docker should now be fully installed.
 
=Updating Discoruse=
 
This section will describe how to update the Discourse software
 
==Discourse Versions==
 
First, a note about Discourse releases: Discourse maintains a "stable" release, but they don't actually backport bug patches to their stable releases like one would expect. There's no LTS (or STS!) for Discourse stable releases.
 
They only fix bugs in future beta releases (which will also include new commits that may break more things). Therefore, the default branch for production is "beta" releases, and they urge their customers not to use "stable." I honestly think this is a terrible idea, especially for a small org like OSE without any full-time ops staff to constantly update our prod apps.
 
* https://github.com/discourse/discourse/releases
 
IMHO, the takeaway to this is that updates should be done to Discourse very carefully and with through testing in staging before taking a backup and following the identical procedure on production.
 
==Check for Updates==
 
Discourse updates often, and it will tell you to update the app (requiring downtime) even if there's 1 (untested?) commit to their discourse github repository
 
* https://github.com/discourse/discourse/
 
==Step 0: Trigger Backup Scripts for System-Wide backup==
 
For good measure, trigger a backup of the entire system's database & files:
 
<pre>
sudo su -
time sudo /bin/nice /root/backups/backup.sh &>> /var/log/backups/backup.log
exit
</pre>
 
When finished, list the backup files in our [[Backblaze]] B2 server backups bucket to verify that the whole system backup was successful before proceeding
 
<pre>
source /root/backups/backup.settings
$SUDO -u ${b2UserName} $B2 ls ${B2_BUCKET_NAME}
</pre>
 
==Step 1: Set variables==
 
Type these commands to set some variables, which will be used by the commands in the sections below. Replace 'www.opensourceecology.org' with the corresponding directory for the wp site you're updating.
 
<pre>
sudo su -
export vhostDir="/var/discourse/"
export stamp=`date +%Y%m%d_%T`
export tmpDir="/var/tmp/discourseUpgrade.${stamp}"
 
# verify
echo "${vhostDir}"
echo "${stamp}"
echo "${tmpDir}"
ls -lah "${vhostDir}"
</pre>
 
==Step 2: Make Vhost-specific backups==
 
The backups made in the previous step are huge. Because it's easier to work with vhost-specific backups, let's make a redundant copy available in /var/tmp/:
 
<pre>
mkdir "${tmpDir}"
chown root:root "${tmpDir}"
chmod 0700 "${tmpDir}"
pushd "${tmpDir}"
 
# discourse backup (db & uploaded files only)
nice rm -rf /var/discourse/shared/standalone/backups/default/*.tar.gz
time nice docker exec discourse_ose discourse backup
nice mv /var/discourse/shared/standalone/backups/default/*.tar.gz ${tmpDir}/
 
# files backup (all discourse files)
time nice tar --exclude "${vhostDir}/shared/standalone/postgres_data" --exclude "${vhostDir}/shared/standalone/postgres_data/uploads" --exclude "${vhostDir}/shared/standalone/backups" -czf ${tmpDir}/discourse_files.${stamp}.tar.gz /var/discourse/*
 
popd
</pre>
 
==Step 3: Update git==
 
We've made some OSE-specific changes to the files in <code>/var/discourse</code> that conflict with the upstream git repo, so let's move those out of the way before updating. After the <code>git pull</code>, we'll update them again.
 
First execute the commands shown in the example below as root to get a list of all the files that have been modified locally.
 
<pre>
[root@osestaging1 /]# pushd /var/discourse
/var/discourse /
[root@osestaging1 discourse]# git status --short | grep -E '^\s*M'
M image/base/install-nginx
M launcher
[root@osestaging1 discourse]# popd
/
[root@osestaging1 /]#
</pre>
 
In the example above, we see that the '<code>/var/discourse/launcher</code>' script and '<code>/var/discourse/image/base/install-nginx</code>' script have both been modified in our custom OSE install. Now let's move those two files out of the way so we can do a clean `<code>git pull</code>` after.
 
Execute the following commands as root. If there were more than just the two files listed above that were modified, then you should update this documentation to reflect the necessary changes.
 
<pre>
export vhostDir="/var/discourse/"
stamp=`date "+%Y%m%d_%H%M%S"`
 
# launcher
mv "${vhostDir}/launcher" "${vhostDir}/launcher.${stamp}"
git checkout "${vhostDir}/launcher"
 
# install-nginx
mv "${vhostDir}/image/base/install-nginx" "${vhostDir}/image/base/install-nginx.${stamp}"
git checkout "${vhostDir}/image/base/install-nginx"
</pre>
 
Now sync to the upstream repo
 
<pre>
pushd "${vhostDir}"
git pull origin master
popd
</pre>
 
Before proceeding, let's get a diff of the changes so we can understand what may have changed upstream, which might break our commands in our OSE Discourse install guide
 
<pre>
diff "${vhostDir}/image/base/install-nginx.${stamp}" "${vhostDir}/image/base/install-nginx"
diff "${vhostDir}/launcher.${stamp}" "${vhostDir}/launcher"
</pre>
 
Write down the output from the above commands in your log; you may need it to debug later.
 
Next, to re-apply the changes to the '<code>install-nginx</code>' script and "<code>launcher</code>' script, see the following relevant section for a list of the necessary commands:
 
# [[#Nginx_mod_security]]
 
See also https://meta.discourse.org/t/how-do-i-manually-update-discourse-and-docker-image-to-latest/23325
 
==Step 4: Build Discourse docker image with OSE modifications==
 
Now we must rebuild the upstream Discourse Docker image with our OSE-specific modifications, such as giving nginx mod_security support.
 
<pre>
pushd "${vhostDir}/image/base"
 
# force a fresh build (no-cache) so the `git pull` lines will trigger
# note this will take a *ridiculously* long time; the Discourse team compiles many packages from source :(
time nice docker build --no-cache --network=host --tag 'discourse_ose' /var/discourse/image/base/
 
popd
</pre>
 
==Step 5: Rebuild the app==
 
<pre>
time nice ${vhostDir}/launcher rebuild discourse_ose
</pre>
 
=Looking Forward=
 
This section will outline possible changes to be made to the Docker install/config in the future
 
==Moving DBs outside docker==
 
It's worthwhile to consider moving the redis and postgresql components of Discourse outside of the docker container <ref>https://meta.discourse.org/t/performance-scaling-and-ha-requirements/60098/8</ref>


=MJ Feb 2019 Review=
=MJ Feb 2019 Review=
Line 1,213: Line 468:
# Whonix https://forums.whonix.org/
# Whonix https://forums.whonix.org/
# Manjaro https://forum.manjaro.org
# Manjaro https://forum.manjaro.org
=Alternatives=
A much simpler-to-maintain alternative to Discourse might be [[Flarum]]


=See Also=
=See Also=


* [[Discourse/Updating]]
* [[Discourse/Install]]
* [[OSE Forum]]
* [[OSE Forum]]
* [[Vanilla Forums]]
* [[Vanilla Forums]]
Line 1,224: Line 485:


=Links=
=Links=
#[[Michael Log]]
#[[Using Discourse]]
#'''[[OSE Forums]]'''
#[[Discourse Install Log]]
#[[Discourse Install Log]]
# https://docs.discourse.org- API Docs only (not very useful)
# https://docs.discourse.org API Docs only (not very useful)
# https://meta.discourse.org/c/10-howto - "howto" tagged topics on meta.discourse.org
# https://meta.discourse.org/c/10-howto - "howto" tagged topics on meta.discourse.org
# https://meta.discourse.org/c/howto/faq/4 - Discourse FAQ
# https://meta.discourse.org/c/howto/faq/4 - Discourse FAQ
Line 1,231: Line 495:
# https://meta.discourse.org/t/where-are-all-the-discourse-logs/58022
# https://meta.discourse.org/t/where-are-all-the-discourse-logs/58022
# https://meta.discourse.org/t/discourse-moderation-guide/63116
# https://meta.discourse.org/t/discourse-moderation-guide/63116
#
#Civilized Discourse Construction Kit - positively biased post about Discourse by its founder - [https://blog.codinghorror.com/civilized-discourse-construction-kit/]
#Civilized Discourse Construction Kit - positively biased post about Discourse - [https://blog.codinghorror.com/civilized-discourse-construction-kit/]
# https://www.slant.co/options/2789/~discourse-review
# https://www.slant.co/options/2789/~discourse-review
# https://forums.whonix.org/t/change-whonix-forum-software-to-discourse/1181
# https://forums.whonix.org/t/change-whonix-forum-software-to-discourse/1181

Latest revision as of 00:04, 28 February 2023

This article describes OSE's use of the Discourse software.

For a detailed guide to updating our Discourse server, see Discourse/Updating.

For a detailed guide on how we installed Discourse in 2020 on our CentOS 7 server, see Discourse/Install.

Official Discourse Documentation

Discourse doesn't have any official documentation outside of their API documentation.

It appears that this is intentional to make Discourse admins' lives difficult as a way to increase revenue. See #Strategic Open Source for more info.

TODO

List of outstanding tasks before attempting to install Discourse on production:

  1. iptables rules that prevent the discourse app from being able to initiate calls to the Internet (it should *only* be able to *respond* to queries) as we do for our apache backend by blocking non-established traffic from going through the OUTPUT table by the apache uid
    1. test an upgrade after this is done as well.
  2. OWASP CORS rules to prevent sqli/XSS/etc attacks as we do in apache
    1. update the install-nginx script so that it compiles nginx with mod_security (and probably downloads the OWASP CRS as well) https://github.com/discourse/discourse_docker/blob/416467f6ead98f82342e8a926dc6e06f36dfbd56/image/base/install-nginx
    2. add a new templates/web.modsecurity.yml file that updates the /etc/nginx/conf.d/discourse.conf file to enable mod_security (and add some blacklisted rules as-needed), similar to the existing web.socketed.template.yml file https://github.com/discourse/discourse_docker/blob/416467f6ead98f82342e8a926dc6e06f36dfbd56/templates/web.socketed.template.yml
  3. iptables on docker container instead of total internet blocking so the docker container can actually update its own OS packages?
    1. TODO: document update to `launcher` script's run_start() function's final `docker run` command to add the argument '--add-cap=NET_ADMIN' so the docker container root's user has permission to modify iptables rules.
  4. Fix unattended-upgrade https://meta.discourse.org/t/does-discourse-container-use-unattended-upgrades/136296
  5. Test/document Discourse upgrade process
  6. Test/document backup & restore process
  7. Stable cron job for docker image cleanup to prevent disk-fill
  8. Varnish cache https://meta.discourse.org/t/discourse-purge-cache-method-on-content-changes/132917
  9. Minimum/hardened permissions of the /var/discourse dir https://meta.discourse.org/t/minimum-hardened-file-permissions/148974

Useful Commands

This section will describe useful commands when working with Discourse 

# get docker info
docker info

# list running docker containers
docker ps

# list all docker containers
docker ps -a

# list all docker images
docker image list

# get docker disk usage (including reclaimable space)
docker system df

# get a shell on the Discourse's docker container
/var/discourse/launcher enter discourse_ose

# access the rails console (exec from inside the docker container)
rails c

# restart a process from within the docker container (ie: cron, nginx, postgres, redis, rsyslog, unicorn)
sv stop nginx && sv start nginx

# stop/start/restart the Discourse container
/var/discourse/launcher stop discourse_ose
/var/discourse/launcher start discourse_ose
/var/discourse/launcher restart discourse_ose

# "rebuild" Discourse app (ie: for upgrades or changes to "templates/" yaml files)
# Takes 5-20 minutes to run, and it may break. Test on staging first.
/var/discourse/launcher rebuild discourse_ose

# "enter" a docker image to inspect/debug/troubleshoot the image itself
[root@osestaging1 ~]# docker image ls
REPOSITORY                      TAG                 IMAGE ID            CREATED             SIZE
local_discourse/discourse_ose   latest              b4d3feecf9e1        5 days ago          2.62GB
discourse_ose                   latest              2ea22070a06d        2 weeks ago         2.33GB
[root@osestaging1 ~]# docker run --rm -it --entrypoint /bin/bash 2ea22070a06d
root@00841db59cd7:/# 

# get capabilities of discourse docker container
id=`docker inspect --format="{{.Id}}" discourse_ose`
grep -E 'CapAdd|CapDrop|Capabilities' /var/lib/docker/containers/$id/hostconfig.json

# tail "outer" nginx logs
tail -c0 -f /var/log/nginx/*log /var/log/nginx/discourse.opensourceecology.org/*log

# monitor varnish for discourse-specific queries only
varnishlog -q "ReqHeader eq 'Host: discourse.opensourceecology.org'"

# tail "inner" discourse logs (run this on the docker host, not inside the container)
tail -c0 -f /var/discourse/shared/standalone/log/rails/*log /var/discourse/shared/standalone/log/var-log/redis/current /var/discourse/shared/standalone/log/var-log/postgres/current /var/discourse/shared/standalone/log/var-log/nginx/*log

Troubleshooting

This section will provide tips on how to troubleshoot the Discourse install

Important Files & Directories

For more information about our Discourse configuration, please see the following files & directories on the Docker Host: 

/var/discourse/
/var/discourse/launcher
/var/discourse/containers/discourse_ose.yml
/var/discourse/templates/
/var/discourse/templates/templates/iptables.template.yml
/var/discourse/templates/templates/postgres.template.yml
/var/discourse/templates/templates/redis.template.yml
/var/discourse/templates/templates/web.template.yml
/var/discourse/templates/templates/web.ratelimited.template.yml
/var/discourse/templates/templates/web.socketed.template.yml
/var/discourse/templates/templates/web.modsecurity.template.yml
/var/discourse/image/base/
/var/discourse/image/base/Dockerfile
/var/discourse/image/base/install-nginx

And the following logs may be helpful: 

/var/discourse/shared/standalone/log/rails/production.log
/var/discourse/shared/standalone/log/rails/unicorn.stderr.log
/var/discourse/shared/standalone/log/var-log/redis/current
/var/discourse/shared/standalone/log/var-log/nginx/{access.log,error.log}
/var/discourse/shared/standalone/log/var-log/postgres/current

And the following files & directories inside the Discourse Docker Container: 

/var/www/discourse/
/var/www/discourse/public
/etc/nginx/conf.d/discourse.conf

Web Server Issues

This section will cover troubleshooting issues with Nginx, Varnish, etc.

Below will be just a list of error messages posted here primarily for the purpose of catching search queries on this wiki and directing them to this text:

To troubleshoot Discourse web server issues, this is a reminder: remember that there are two distinct nginx servers:

  1. nginx running on the server (docker host)
  2. nginx running _inside_ the discourse container running on the server

Don't forget to troubleshoot both! 

user@ose:~$ curl -kI https://discourse.opensourceecology.org/
HTTP/1.1 502 Bad Gateway
Server: nginx
Date: Mon, 30 Mar 2020 09:03:23 GMT
Content-Type: text/html
Content-Length: 150
Connection: keep-alive

user@ose:~$

502 Bad Gateway

Relevant error messages:

  • cURL
Failed to connect to discourse.opensourceecology.org port 80: Connection refused

Unable to Connect

Relevant error messages:

  • cURL
Failed to connect to discourse.opensourceecology.org port 80: Connection refused
  • Firefox
Unable to connect

Firefox can’t establish a connection to the server at discourse.opensourceecology.org.

    The site could be temporarily unavailable or too busy. Try again in a few moments.
    If you are unable to load any pages, check your computer’s network connection.
    If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web.
  • Chromium
This site can’t be reached discourse.opensourceecology.org refused to connect.
Try:

Checking the connection
Checking the proxy and the firewall
ERR_CONNECTION_REFUSED

This is because literally nothing is responding on the ip address and port.

`git pull` fail

The built-in Discourse 'launcher' script may try to do a `git pull` that may fail when it tries to update a file that we've modified in OSE's config. For example: 

[root@osestaging1 discourse]# /var/discourse/launcher rebuild discourse_ose
Ensuring launcher is up to date
Fetching origin
remote: Enumerating objects: 6, done.
remote: Counting objects: 100% (6/6), done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 6 (delta 2), reused 2 (delta 2), pack-reused 0
Unpacking objects: 100% (6/6), done.
From https://github.com/discourse/discourse_docker
   bb9a173..b0c92ba  master     -> origin/master
Updating Launcher
Updating bb9a173..b0c92ba
error: Your local changes to the following files would be overwritten by merge:
		launcher
Please, commit your changes or stash them before you can merge.
Aborting
failed to update
Ensuring launcher is up to date
Fetching origin
Updating Launcher
Updating bb9a173..b0c92ba
error: Your local changes to the following files would be overwritten by merge:
		launcher
Please, commit your changes or stash them before you can merge.
Aborting
failed to update
Ensuring launcher is up to date
Fetching origin
Updating Launcher
Updating bb9a173..b0c92ba
...

The above output was an endless loop complaining about the conflict between the file 'launcher' in the '/var/discourse/' directory. In order to fix the conflict, you must merge the changes--which may be a non-trivial process.

The easiest action is to just move the locally modified files out of the way, do a clean `git pull`, make note a diff of the changes, and re-apply the local changes by re-visiting the relevant section of install guide. For detailed instructions on this process, see the "Updating Discourse" #Step 3: Update git section.

Removal In Progress

You may get an error when attempting to rebuild the Discourse docker container because an old docker container is stuck in a "Removal In Progress" state. For example: 

[root@osestaging1 discourse]# time /var/discourse/launcher rebuild discourse_ose
...
169:M 23 Mar 2020 10:19:33.054 # Redis is now ready to exit, bye bye...
2020-03-23 10:19:33.127 UTC [52] LOG:  database system is shut down
sha256:6e6c81a3529175c1aa8e3391599499704f3abb9833ca3e943cf1b5443da4f47c
fbf51479947c537d2247bf38bd0ca2f1cb96257dbbf86e93038e6a19f2bab5d6
Removing old container
+ /bin/docker rm discourse_ose
Error response from daemon: container 12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8: driver "overlay2" failed to remove root filesystem: unlinkat /var/lib/docker/overlay2/99f609ae22d509152fd6db0120ba111c4d892b153d41d2e720790c864d5d678a/merged: device or resource busy

starting up existing container
+ /bin/docker start discourse_ose
Error response from daemon: container is marked for removal and cannot be started
Error: failed to start containers: discourse_ose

real    8m39.585s
user    0m1.764s
sys     0m1.684s
[root@osestaging1 discourse]#

Restarting docker _may_ help you to manually delete the docker container. Or not 

[root@osestaging1 containers]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                PORTS               NAMES
12bb1e40517b        4d92ff0b76a7        "/sbin/boot"        6 days ago          Removal In Progress                       discourse_ose
[root@osestaging1 containers]# systemctl restart docker
[root@osestaging1 containers]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
12bb1e40517b        4d92ff0b76a7        "/sbin/boot"        6 days ago          Dead                                    discourse_ose
[root@osestaging1 containers]# docker rm 12bb1e40517b
Error response from daemon: container 12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8: driver "overlay2" failed to remove root filesystem: unlinkat /var/lib/docker/overlay2/99f609ae22d509152fd6db0120ba111c4d892b153d41d2e720790c864d5d678a/merged: device or resource busy
[root@osestaging1 containers]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                PORTS               NAMES
12bb1e40517b        4d92ff0b76a7        "/sbin/boot"        6 days ago          Removal In Progress                       discourse_ose
[root@osestaging1 containers]#

This issue coincides with the following error being written to the systemd journal log 

Mar 23 10:44:55 osestaging1 dockerd[16920]: time="2020-03-23T10:44:55.578997874Z" level=error msg="Error removing mounted layer 12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8: unlinkat /var/lib/docker/overlay2/99f609ae22d509152fd6db0120ba111c4d892b153d41d2e720790c864d5d678a/merged: device or resource busy"
Mar 23 10:44:55 osestaging1 dockerd[16920]: time="2020-03-23T10:44:55.579614708Z" level=error msg="Handler for DELETE /v1.40/containers/12bb1e40517b returned error: container 12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8: driver \"overlay2\" failed to remove root filesystem: unlinkat /var/lib/docker/overlay2/99f609ae22d509152fd6db0120ba111c4d892b153d41d2e720790c864d5d678a/merged: device or resource busy"

A fix is to stop docker, force remove the problem container's directory, and start docker again. It would be wise to make a backup before attempting to proceed with this, just in-case you permanently delete the wrong container's directory! 

[root@osestaging1 containers]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                PORTS               NAMES
12bb1e40517b        4d92ff0b76a7        "/sbin/boot"        6 days ago          Removal In Progress                       discourse_ose
[root@osestaging1 containers]# docker ps -a --no-trunc
CONTAINER ID                                                       IMAGE                                                                     COMMAND             CREATED             STATUS                PORTS               NAMES
12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8   sha256:4d92ff0b76a725a5252fce8567e961fc01eebe68c2b34d1abc9c94cae041597e   "/sbin/boot"        6 days ago          Removal In Progress                       discourse_ose
[root@osestaging1 containers]# systemctl stop docker
[root@osestaging1 containers]# rm -rf /var/lib/docker/containers/12bb1e40517bb4893ff428096fa204f145c75d64be6a269cbe3093543373c6a8
[root@osestaging1 containers]# systemctl start docker
[root@osestaging1 containers]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
[root@osestaging1 containers]#

Installing Themes and Components

By design, our web servers can only respond to requests; they cannot initiate requests. And Discourse is no different.

This means that the usual route of installing themes and components in Discourse via the WUI (Admin -> Customize -> Themes -> Install -> Popular -> Install) won't work. 

Error cloning git repository, access is denied or repository is not found

Step #1: Find repo

To install a theme or theme component in our Discourse, first find its git repo. You can find many Discourse theme repos by listing all repos tagged with the topic 'discourse-theme' or 'discourse-theme-component' in the Discourse project on github. 

* https://github.com/search?q=topic%3Adiscourse-theme+org%3Adiscourse+fork%3Atrue
* https://github.com/search?q=topic%3Adiscourse-theme-component+org%3Adiscourse+fork%3Atrue

Step #2: Download zip

202005 discourseInstallTheme1.jpg

For example, here's a link to the github repo for the Discourse "Classic Theme" 

* https://github.com/discourse/discourse-classic

From the theme's github repo page, download a zip of the repo by clicking "Clone or download" -> "Download ZIP"


Step #3: Upload zip

202005 discourseInstallTheme2.jpg

Now, login to our Discourse site and navigate to Admin -> Customize -> Themes

Click Install


202005 discourseInstallTheme3.jpg

In the JS modal "pop-up", choose From your device.

Finally, click Browse and upload the .zip file downloaded above.


Looking Forward

This section will outline possible changes to be made to the Docker install/config in the future

Moving DBs outside docker

It's worthwhile to consider moving the redis and postgresql components of Discourse outside of the docker container [1]

Strategic Open Source

202005 discourseStrategicOpenSource PURGEtopic1.jpg
202005 discourseStrategicOpenSource PURGEtopic2.jpg

As of 2020, Discourse does appear to be the best solution to replace our deprecated Vanilla Forums. Unfortunately, it became clear over the course of its POC that the Discourse project is yet another example of Strategic Open Source.

While the code is open, Discourse does not have a open and collaborative culture.

This escalated in May 2020 on meta.discourse.org after I (Michael Altfield) published my varnish config to a topic I was using to document integration of Discourse with Varnish. The Discourse staff told me (again) that Discourse already has built-in caching.

I responded (again) asking where their built-in caching was documented. Then Jeff Atwood (co-founder of Discourse) stepped-in and linked me to their source code. Frustrated, I asked:

Michael Altfield: Serious question: Does the discourse team have a policy against writing documentation? Does the discourse project have any documentation-related policies at all?

Atwood's response was to threaten to ban me

Jeff Atwood: We do have a policy against people being rude to us. Would you like to explore that policy now?

I made clear how I appreciate and value anyone's contributions to an open-source code base and added "but code alone is not a substitute for documentation" before reiterating my question about their documentation polcies. Atwood's response was

Atwood: ...We don't tend to spend time on that, as historically it is not a good use of our engineering budget. If you'd like to pay us...

Then, what really shocked me was that the entire thread was marked to be deleted in 14 days. Note that I had been using this thread as a place to document how to integrate Discourse with Varnish--something that as-yet hasn't been documented in such detail anywhere on the 'net.

I added:

So I just noticed this:

> This topic will be automatically deleted in 14 days.

Please tell me this means this thead will become read-only and not deleted.

I've gone through a lot of effort using this thread as a means to provide documentation to other users, and I want to ensure that it won't be deleted...

Their response? The immediately deleted the entire topic. But not before I made a backup (gif, pdf).

This whole interaction made it clear to me that:

  1. Discourse has a toxic community that doesn't care about open collaboration
  2. Discourse intentionally doesn't document their product
  3. Discourse intentionally deletes user-submitted documentation
  4. I think that Discorse intentionally tries to make their product obscure and their users more helpless as a means to generate revenue


MJ Feb 2019 Review

  • Legend: Check.png = exists, Check.pngCheck.png = good, Check.pngCheck.pngCheck.png = great
  • Check.pngQ&A plugin appears to be adequate, but does not have downvotes. Downvotes are important, as a knowledgeable person should ideally be able to downsize bull****. This is important for collaborative learning - and should be developed to approach the usefulness of Stack Exchange and Reddit. Would need to put development time into this.
  • Check.pngCheck.pngCheck.pngRating - appears excellent - [1]
  • Check.pngCheck.pngCheck.pngCommenting plugin - excellent, up with Disqus. [2]
  • Check.pngCheck.pngCheck.pngBug Tracking - a simple wiki/Discourse hack can be done by a Bugtracking or Known Bugs category on the wiki, and embedding a thread on that bug from Discourse, so discussion can happen, and when resolved, thread can be closed. We'd have to see in practice how this looks. That is the simplest way to go without installing yet another pieces of software, and using Discourse and Wiki hold most of the weight, the rest being Wordpress.

Cons

  • Free to try rather than really free? See last con at [3]

OSE Use Case

  • The generic OSE use case for transparency is using the Wiki for embedding all kinds of content, where the wiki is a proven and scalable tool for collaborative development - and a core tool in OSE's usage. With this said, it is useful to have various forms of content embedded in the wiki, so that we don't have to use many different platforms for different functions: we can just embed content from other common platforms. The intent is modular design where content can be reused and mixed throughout OSE's web presence.
  1. Embed individual Discourse threads on wiki pages. This way we upgrade content from wiki pages to live discussion - where content for discussion can be edited right in the wiki page. The intent of this is to improve the use of the Wiki as a development platform so that the wiki is more intuitive. See embed of thread example - [4]. This must allow any single thread from Discourse to be embedded.
  2. Rating of a service or product - in an open source franchise, products/services of collaborators can be rated. A simple tool like the wiki can have a rating feature - without having to use any other software. This is yet another way to make the wiki more functional and user-friendly. See example - [5]
  3. Upvoting - no evidence of Discourse serving this function well compared to Askbot. By upvoting, we mean simply that all the content remains visible, and a single solution is not marked. This allows users to pick nuggets from different answers - while allowing bulk filtering to occur before looking at the answer. From the OSE perspective, marking a question as resolved is not inclusive or abundant. What if someone else has a better solution? It may be that Discourse can be modified to do upvoting readily, or can simulate this function well - but we would have to see in practice if this is feasible.

2018-09 Review

In 2018-09, I (Michael Altfield) had just learned about Discourse as I was working on the phplist project. phplist's forums use Discourse. At the same time, Alex Au recommended to Marcin that we setup a replacement forum using Discourse.

Pros

  1. Very pleasant interface
  2. Very nice functionality ootb. Badges, user trust system for easy moderation, climbing ranks, love, at-calls (@), etc -- co-founder Jeff Atwood also founded Stack Exchange, so expect similar functionality
  3. Very popular. Many, many forums have switched to Discourse over the past several years
  4. Great selection of plugins & integrations (though no decent db/index for searching them) https://meta.discourse.org/c/plugin https://github.com/discourse
    1. ie: replace wordpress comments with a discourse thread. This may or may not be good.
      1. Example wordpress blog post: https://blog.discourse.org/2018/06/understanding-discourse-trust-levels/
      2. Corresponding discourse thread for the comments to the above post: https://meta.discourse.org/t/wp-discourse-dysfunctional-shows-only-start-the-discussion-at/36016
  5. Looks like we can import our content from Vanila https://meta.discourse.org/t/how-to-migrate-from-vanilla-to-discourse/27273
  6. Well-funded org that hosts their project (think wordpress.com) for many of their customers. The good here is that Discorse can pay a salary to devs, unlike many open source projects. But it's worth nothing that people choose to pay for hosting probably because it's Ruby on Rails, and a PIA to self-host.
  7. While not officially supported, it looks like users have setup Discourse behind varnish 4 [2]

Cons

  1. Ruby on rails
  2. They openly state that they're hard to install, and therefore _only_ support installation via a docker container [3]
  3. I'm seriously worried about the security of a project that thinks it's acceptable to use wget -qO- https://get.docker.com/ | sh as a step in their install guide [4]
  4. Discourse explicitly states that they only support newer devices. I'm concerned that means that we may make our content inaccessible to, say, that 6-year-old desktop running windows xp in the machine shop. Indeed, discourse only supports IE 11+, which came with Windows 8.1 in 2013--5 years ago. [5]
  5. If javascript is disabled, the site is read-only. JS is a requirement for posting, replying, etc. But because Discourse also functions as a mailing list, JS-free users can still contribute content in a limited way by replying to threads via email [6]

Neutral

  1. Project has been around for 5 years (initial release in 2013) https://en.wikipedia.org/wiki/Discourse_%28software%29

Noteable sites using Discourse

  1. Ubuntu https://discourse.ubuntu.com/
  2. Phplist https://discuss.phplist.org/
  3. Whonix https://forums.whonix.org/
  4. Manjaro https://forum.manjaro.org

Alternatives

A much simpler-to-maintain alternative to Discourse might be Flarum

See Also

References

  1. ↑ https://meta.discourse.org/t/performance-scaling-and-ha-requirements/60098/8
  2. ↑ https://meta.discourse.org/t/discourse-behind-varnish/4864/10
  3. ↑ https://github.com/discourse/discourse/blob/master/docs/INSTALL.md#why-do-you-only-officially-support-docker
  4. ↑ https://github.com/discourse/discourse/blob/master/docs/INSTALL-cloud.md#install-docker--git
  5. ↑ https://github.com/discourse/discourse#requirements
  6. ↑ https://forums.whonix.org/t/turn-off-javascript-for-forums/1692/2

Links

  1. Michael Log
  2. Using Discourse
  3. OSE Forums
  4. Discourse Install Log
  5. https://docs.discourse.org API Docs only (not very useful)
  6. https://meta.discourse.org/c/10-howto - "howto" tagged topics on meta.discourse.org
  7. https://meta.discourse.org/c/howto/faq/4 - Discourse FAQ
  8. https://meta.discourse.org/t/advanced-troubleshooting-with-docker/15927
  9. https://meta.discourse.org/t/where-are-all-the-discourse-logs/58022
  10. https://meta.discourse.org/t/discourse-moderation-guide/63116
  11. Civilized Discourse Construction Kit - positively biased post about Discourse by its founder - [6]
  12. https://www.slant.co/options/2789/~discourse-review
  13. https://forums.whonix.org/t/change-whonix-forum-software-to-discourse/1181
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