# Docker Compose notes

This integration is for an existing Mastodon deployment. It does not create a Mastodon stack and does not add a new long-running application container.

The host-side script calls commands equivalent to:

```sh
docker compose exec -T -e RAILS_ENV=production web bin/rails runner '...'
docker compose exec -T -e RAILS_ENV=production web bin/tootctl email-domain-blocks add ...
```

The official Mastodon Compose file uses a `web` service for the Rails application. Other distributions and custom Compose files may use a different service name; set `--compose-service` accordingly.

Before running the blocker, these two checks should succeed from the Compose directory:

```sh
docker compose exec -T web bin/rails runner 'puts EmailDomainBlock.count'
docker compose exec -T web bin/tootctl email-domain-blocks list --help
```

If the local deployment uses a wrapper, a different Compose project directory, or the old `docker-compose` binary, adjust `--compose-dir` and `--compose-command`. The Python program does not need access to the database container and should not be given database credentials.