Running Discourse with a separate PostgreSQL server


Anu reference or file need to be removed?

I needed to run development discourse (set up following Beginners Guide to Install Discourse for Development using Docker ) using database from another container. To do so, I had to modify the installation steps as follows:

  1. git clone
  2. cd discourse
  3. vim config/database.yml , on the top of the file, make it into:
  prepared_statements: false
  adapter: postgresql
  #database: <%= ENV['DISCOURSE_DEV_DB'] || 'discourse_development' %>
  database: discourse
  username: discourse
  password: yourdbpassword
  host: postgres
  min_messages: warning
  pool: 5
  timeout: 5000
  checkout_timeout: <%= ENV['CHECKOUT_TIMEOUT'] || 5 %>
    ### Don't include the port number here. Change the "port" site setting instead, at /admin/site_settings.
    ### If you change this setting you will need to
    ###   - restart sidekiq if you change this setting
    ###   - rebake all to posts using: `RAILS_ENV=production bundle exec rake posts:rebake`
    - "localhost"
  1. vim bin/docker/boot_dev, find the line starting with docker run, and add a network definition matching the docker network to which your postgres container is attached to: docker run --network my-docker_network-name -d -p 4305:...
  2. ./bin/docker/boot_dev
  3. ./bin/docker/unicorn
  4. you may need to run migrations: docker exec -it discourse_dev /bin/bash -c "cd /src; ./bin/rails db:migrate RAILS_ENV=development"
  5. visit http://localhost:9292/ and log in with credentials you set up earlier on that database

Is there a simpler way to do it, just with environment variables?

This failed for me. Any suggestions on how to fix it ?
I am able to access DB discourse remotely from command line so the connection to DB looks good

Pups::ExecError: cd /var/www/discourse && su discourse -c 'bundle exec rake db:migrate' failed with return #<Process::Status: pid 274 exit 1>
Location of failure: /pups/lib/pups/exec_command.rb:112:in `spawn'
exec failed with the params {"cd"=>"$home", "hook"=>"db_migrate", "cmd"=>["su discourse -c 'bundle exec rake db:migrate'"]}
** FAILED TO BOOTSTRAP ** please scroll up and look for earlier error messages, there may be more than one

I got the same error with the following lines in the log above:

rake aborted!
PG::ConnectionBad: could not connect to server: Connection refused
        Is the server running on host "" and accepting
        TCP/IP connections on port 5432?

Currently I am trying to find a fix.

The only way for me to rebuild with external postgres was the command mentioned earlier:

 rebuild app --docker-args --net=host --skip-mac-address

But in this case unicorn is started with default port 3000. Exposing ports is disabled as well. I cannot explain exactly, but something has changed since Sep '17, probably in launcher code.

1 Like

Hey guys,

what´s the best practice to migrate from docker based postgre db to dedicated?
The setup of the dedicated is described farther up this thread, right, but how can I then move the data from docker to dedicated db ?
Probably with backup & restore, but is there a tutorial for that available ?

Thanks and greetings,


Ideally, you have discourse stopped.
Dump your database with pg_dump and restore with pg_restore.
see PostgreSQL Restore Database

Before starting up Discourse using the new database, issue as admin:

grant all privileges on database discourse to discourse;
alter schema public owner to discourse;
create extension if not exists hstore;
create extension if not exists pg_trgm;