pl_mail/compose.demo.yaml

# A public demo, on top of the published image.
#
#   SERVER_NAME=demo.example.com \
#   docker compose -f compose.yaml -f compose.demo.yaml up -d --wait
#
# Layers over compose.yaml, not over compose.prod.yaml: that one builds the
# image from source, and a demo has no reason to. Everything here is either the
# demo switch or a consequence of it.
#
# APP_DEMO_MODE is hardcoded rather than interpolated, and that is the whole
# reason this file exists instead of a line in a README. `docker compose` reads
# the `.env` beside it — Symfony's, committed — and that file says
# APP_DEMO_MODE=0. A `${APP_DEMO_MODE:-1}` here would therefore resolve to 0 for
# every operator who cloned the repo, and the stack would come up looking
# perfectly healthy and not be a demo at all: no /demo route, no button, and
# real IMAP sync attempts against accounts pointing at example.com. That is the
# same trap APP_ENV fell into once — see ComposeEnvironmentTest, which holds
# this file to the rule too.
#
# Before putting one on the internet: give it its own APP_SECRET and
# APP_ENCRYPTION_KEY and never reuse them from an install holding real mail.
# The encryption key is what reads mailbox passwords, and a box where anyone can
# log in is the last place a real one should exist. Left unset, secrets-init
# mints fresh ones into the demo's own volume, which is what you want.
#
# See docs/install/demo-mode.md.

# APP_ENV is spelled out beside the demo switch rather than inherited, for the
# reason ComposeEnvironmentTest gives: a file that configures the app services
# should say which environment it is configuring them for, so that it cannot be
# read as "whatever the base happened to say".
x-demo-env: &demo-env
  APP_ENV: prod
  APP_DEMO_MODE: "1"
  # Safe to interpolate: `.env` sets exactly this value, so an operator who
  # never heard of the variable gets the documented default either way.
  APP_DEMO_TTL: ${APP_DEMO_TTL:-PT2H}

  # The legal notice. Passed through explicitly, because compose hands a
  # container only what a service declares — putting these in an .env file
  # makes them available for ${…} interpolation and nothing else. Without these
  # three lines the operator sets them, restarts, and the page still says they
  # are unset, with nothing anywhere explaining why.
  #
  # Empty defaults, matching the shipped .env, so the page keeps saying loudly
  # that it has no operator until somebody gives it one.
  APP_DEMO_IMPRESSUM_NAME: ${APP_DEMO_IMPRESSUM_NAME:-}
  APP_DEMO_IMPRESSUM_ADDRESS: ${APP_DEMO_IMPRESSUM_ADDRESS:-}
  APP_DEMO_IMPRESSUM_EMAIL: ${APP_DEMO_IMPRESSUM_EMAIL:-}
  APP_DEMO_PRIVACY_HOST: ${APP_DEMO_PRIVACY_HOST:-}

services:
  # Serves /demo, provisions visitors and renders the demo bar.
  php:
    environment:
      <<: *demo-env

  # Every background process but one, and each is needed:
  #
  #   - worker-ingest delivers the scripted mail the Receive button asks for,
  #     and the auto-reply to anything a visitor sends. Without it the button
  #     appears to do nothing: the job is queued and never handled.
  #   - worker-export: nothing outbound leaves a demo (DemoMailSender swallows
  #     it), but a send still travels through this queue, so without it Send
  #     sits pending.
  #   - worker-bulk: a demo's mailboxes are small, so a bulk action is quick,
  #     but without the consumer its indicator would sit at nothing for ever.
  #   - the scheduler runs app:demo:reap every ten minutes. Without it expired
  #     visitors are never deleted, and the database grows by a user, an
  #     account, ten threads and ten contacts for everybody who followed the
  #     link, with nothing anywhere saying so.
  #   - the Mercure hub is what refreshes a visitor's inbox when mail arrives.
  #
  # The IMAP supervisor is the one left out. It holds an IDLE connection per
  # mailbox, and a demo has no mailbox to hold one to: its accounts point at
  # documentation domains that resolve nowhere, so it would spend the whole
  # time failing to connect and backing off.
  worker:
    command: php bin/console app:work --without=imap-supervisor
    environment:
      <<: *demo-env