16 Nov 2014

I wanted to try and use Docker after hearing such great things about it. Since I might want to roll out a decent forum at some point, I wanted to look into installing Discourse. For the moment, this will be done on my desktop.

I start with the installation instructions for Docker on Ubuntu 14.04.

  • For Discourse it's needed to follow the instructions for the newest version of Docker and not to use the default Ubuntu package.

I proceed with this tutorial that specifies to run:

wget -qO- https://get.docker.io/ | sh
mkdir /var/docker
git clone https://github.com/discourse/discourse_docker.git /var/docker
cd /var/docker
cp samples/standalone.yml containers/app.yml

I modify /var/docker/containers/app.yml (all relevant changes to app.yml are at the bottom)


but on running start sudo ./launcher start app I get:

2014/11/16 10:46:31 Error response from daemon: Cannot start container 270d47cd8401c50f13e0a1e51428f5b9833a9480b53bc98735df55b425a70b6d: Error starting userland proxy: listen tcp bind: address already in use

This could be expected, because Apache runs on port 80.

in /var/docker/containers/app.yml there is an entry:

  - "80:80"   # fwd host port 80   to container port 80 (http)
  - "2222:22" # fwd host port 2222 to container port 22 (ssh)

After using netstat -antp to confirm port 8080 is unused, I change 80:80 to 8080:80 in the app.yml.

Now I rebuild and restart the container:

cd /var/docker
sudo ./launcher rebuild app # this applies the changes
sudo ./launcher start app

When I use the browser to go to http://localhost:8080/, it immediately gives me Discourse page!

Now I notice, when creating the admin account, that the activation mail is not send. Thinking back I did skip over the mail settings in the app.yml.

Here I had to experiment a bit with my mail settings and this turned out in the end what took most of the time for getting Discourse up and running. One thing I learned is that it's not neccesary to stop the app with sudo ./launcher stop app before making changes or rebuilding.

Soon I find that running sudo ./launcher mailtest app gives much more useful information, thanks to this thread.

I configure the app.yml to use the Google smtp server (settings are below), but sudo ./launcher mailtest app still gives an error:

ERROR: python yaml module not installed - run the following and try again:

sudo apt-get install python3-yaml

After installing this package mailtest tells me there is an authentication problem and apparently I need to allow "less secure apps" access to my gmail account. After setting this up at Google accounts, I can send mail with mailtest.

The activate mail link is now send and I can access the admin panel in Discourse.

I have also tried to set up mail with the SMTP settings of my own ISP, but this gave an error that I could not find any solutions to:

Traceback (most recent call last):
  File "/var/docker/scripts/mailtest", line 138, in <module>
    smtp = smtplib.SMTP(smtp_addr, smtp_port, timeout=5)
  File "/usr/lib/python3.4/smtplib.py", line 242, in __init__
    (code, msg) = self.connect(host, port)
  File "/usr/lib/python3.4/smtplib.py", line 321, in connect
    self.sock = self._get_socket(host, port, self.timeout)
  File "/usr/lib/python3.4/smtplib.py", line 292, in _get_socket
  File "/usr/lib/python3.4/socket.py", line 509, in create_connection
    raise err
  File "/usr/lib/python3.4/socket.py", line 500, in create_connection
OSError: [Errno 113] No route to host

Since I never use my ISP's mail server, it might simply be that I use the wrong SMTP address or something.

In the end, I use these setting in my app.yml (these are just the edited fragments):

  - "8080:80"  # fwd host port 80   to container port 80 (http)
  - "2222:22"  # fwd host port 2222 to container port 22 (ssh)

  DISCOURSE_DEVELOPER_EMAILS: 'myemail@example.com'


  DISCOURSE_SMTP_ADDRESS: smtp.gmail.com
  DISCOURSE_SMTP_USER_NAME: mygmail@gmail.com

I wonder now, since I'm starting discourse now with ./launcher start app if I should have renamed the containers/app.yml to discourse.yml to be able to start Discourse with ./launcher start discourse? I don't know how difficult (or easy?) it will be to change this afterwards, but I will leave it for another time to figure this out.