Guidance on multi-site setup

Installation
1

Hi everyone!

I’ve been working on setting up a multi-site Discourse instance, and while I’ve made some progress, I’m running into a few roadblocks and could really use some guidance from someone. I’ve gone through the Multisite configuration with Docker guide, but I still have a few questions:

  1. Where can I find the “multisite.yml” file that’s mentioned? I don’t see it in my discourse/templates folder.
  2. Do I need to set up hooks for after_postgres even if I’m just using the standard volume and not a dedicated database?
  3. Is there a simple app.yml template for a basic multi-site setup? I’m not looking to add plugins or anything fancy—just something straightforward to get started.

For context, I’m currently running a standard Discourse instance on a GCP VM, accessible via mamacares. My app.yml is pretty much the default—no plugins or dedicated database. If anyone has experience with this or knows of a quick start guide for setting up a multi-site configuration, I’d really appreciate the help!

This is my current app.yml for reference (I removed the sensitive data)

## this is the all-in-one, standalone Discourse Docker container template
##
## After making changes to this file, you MUST rebuild
## /var/discourse/launcher rebuild app
##
## BE *VERY* CAREFUL WHEN EDITING!
## YAML FILES ARE SUPER SUPER SENSITIVE TO MISTAKES IN WHITESPACE OR ALIGNMENT!
## visit http://www.yamllint.com/ to validate this file as needed

templates:
  - "templates/postgres.template.yml"
  - "templates/redis.template.yml"
  - "templates/web.template.yml"
  ## Uncomment the next line to enable the IPv6 listener
  #- "templates/web.ipv6.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:
  db_default_text_search_config: "pg_catalog.english"

  ## Set db_shared_buffers to a max of 25% of the total memory.
  ## will be set automatically by bootstrap based on detected RAM, or you can override
  db_shared_buffers: "256MB"

  ## can improve sorting performance, but adds memory usage per-connection
  #db_work_mem: "40MB"

  ## Which Git revision should this container use? (default: tests-passed)
  #version: tests-passed

env:
  LC_ALL: en_US.UTF-8
  LANG: en_US.UTF-8
  LANGUAGE: en_US.UTF-8
  # DISCOURSE_DEFAULT_LOCALE: en

  ## How many concurrent web requests are supported? Depends on memory and CPU cores.
  ## will be set automatically by bootstrap based on detected CPUs, or you can override
  UNICORN_WORKERS: 4

  ## TODO: The domain name this Discourse instance will respond to
  ## Required. Discourse will not work with a bare IP number.
  DISCOURSE_HOSTNAME: 'www.mamacares.com'

  ## Uncomment if you want the container to be started with the same
  ## hostname (-h option) as specified above (default "$hostname-$config")
  #DOCKER_USE_HOSTNAME: true

  ## TODO: List of comma delimited emails that will be made admin and developer
  ## on initial signup example 'user1@example.com,user2@example.com'
  DISCOURSE_DEVELOPER_EMAILS: '---------'

  ## TODO: The SMTP mail server used to validate new accounts and send notifications
  # SMTP ADDRESS, username, and password are required
  # WARNING the char '#' in SMTP password can cause problems!
  DISCOURSE_SMTP_ADDRESS: ----------
  #DISCOURSE_SMTP_PORT: --------
  DISCOURSE_SMTP_USER_NAME: ----------
  DISCOURSE_SMTP_PASSWORD: ------------
  #DISCOURSE_SMTP_ENABLE_START_TLS: true           # (optional, default true)
  #DISCOURSE_SMTP_DOMAIN: discourse.example.com    # (required by some providers)
  #DISCOURSE_NOTIFICATION_EMAIL: noreply@discourse.example.com    # (address to send notifications from)

  ## If you added the Lets Encrypt template, uncomment below to get a free SSL certificate
  #LETSENCRYPT_ACCOUNT_EMAIL: me@example.com

  ## The http or https CDN address for this Discourse instance (configured to pull)
  ## see https://meta.discourse.org/t/14857 for details
  #DISCOURSE_CDN_URL: https://discourse-cdn.example.com

  ## The maxmind geolocation IP account ID and license key for IP address lookups
  ## see https://meta.discourse.org/t/-/173941 for details
  #DISCOURSE_MAXMIND_ACCOUNT_ID: 123456
  #DISCOURSE_MAXMIND_LICENSE_KEY: 1234567890123456

## The Docker container is stateless; all data is stored in /shared
volumes:
  - volume:
      host: /var/discourse/shared/standalone
      guest: /shared
  - volume:
      host: /var/discourse/shared/standalone/log/var-log
      guest: /var/log

## Plugins go here
## see https://meta.discourse.org/t/19157 for details
hooks:
  after_postgres:
    - exec: sudo -u postgres createdb b_discourse || exit 0
    - exec:
        stdin: |
          grant all privileges on database b_discourse to discourse;
        cmd: sudo -u postgres psql b_discourse
        raise_on_fail: false
    - exec: /bin/bash -c 'sudo -u postgres psql b_discourse <<< "alter schema public
        owner to discourse;"'
    - exec: /bin/bash -c 'sudo -u postgres psql b_discourse <<< "create extension if
        not exists hstore;"'
    - exec: /bin/bash -c 'sudo -u postgres psql b_discourse <<< "create extension if
        not exists pg_trgm;"'
  after_code:
    - exec:
        cd: $home/plugins
        cmd:
          - mkdir -p plugins
          - git clone https://github.com/discourse/docker_manager.git
  before_bundle_exec:
    - file:
        path: $home/config/multisite.yml
        contents: |
          secondsite:
            adapter: postgresql
            database: b_discourse
            pool: 25
            timeout: 5000
            db_id: 2
            host_names:
              #- www.mamacares.com
              - www.vet.community
  after_bundle_exec:
    - exec: cd /var/www/discourse && sudo -E -u discourse bundle exec rake multisite:migrate

## Any custom commands to run after building
run:
  - exec: echo "Beginning of custom commands"
  ## If you want to set the 'From' email address for your first registration, uncomment and change:
  ## After getting the first signup email, re-comment the line. It only needs to run once.
  #- exec: rails r "SiteSetting.notification_email='info@unconfigured.discourse.org'"
  - exec: echo "End of custom commands"

Thanks so much, and looking forward to any advice you can share!

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