Mastodon on Heroku, using Docker

Mastodon is a free, open-source social network server based on ActivityPub.

The Mastodon server is implemented a rails app, which relies on postgres and redis. It uses sidekiq for background jobs, along with a separate nodejs http streaming server.

Docker images: https://hub.docker.com/r/tootsuite/mastodon/

Dockerfile: https://github.com/mastodon/mastodon/blob/main/Dockerfile

docker-compose.yml: https://github.com/mastodon/mastodon/blob/main/docker-compose.yml

Heroku Docker Deploys: https://devcenter.heroku.com/categories/deploying-with-docker

Setup

CLI

Setup your heroku account and CLI:

$ brew install heroku
$ heroku login
$ heroku update beta
$ heroku plugins:install @heroku-cli/plugin-manifest
$ heroku container:login

App

Create the app and addons:

$ heroku create mastodon-test --manifest
$ heroku config:set LOCAL_DOMAIN=mastodon-test.herokuapp.com

Create redis addon at v5 (without TLS):

$ heroku addons:create heroku-redis:premium-0 --version 5

Generate secrets:

$ heroku config:set OTP_SECRET=$(docker run --rm -it tootsuite/mastodon:latest bin/rake secret)
$ heroku config:set SECRET_KEY_BASE=$(docker run --rm -it tootsuite/mastodon:latest bin/rake secret)
$ heroku config:set $(docker run --rm -e OTP_SECRET=placeholder -e SECRET_KEY_BASE=placeholder -it tootsuite/mastodon:latest bin/rake mastodon:webpush:generate_vapid_key | xargs)

Settings

Storage for uploaded user photos and videos

See lib/tasks/mastodon.rake for environment variables available for Wasabi, Minio or Google Cloud Storage.

$ heroku config:set S3_ENABLED=true S3_BUCKET=bbb AWS_ACCESS_KEY_ID=xxx AWS_SECRET_ACCESS_KEY=yyy

Federation

$ heroku config:set LIMITED_FEDERATION_MODE=true

Outgoing email

$ heroku addons:create mailgun
$ heroku config | grep MAILGUN_
$ heroku config:set SMTP_SERVER= SMTP_LOGIN= SMTP_PASSWORD= SMTP_FROM_ADDRESS=

ElasticSearch (optional)

$ heroku addons:create bonsai
$ heroku config:get BONSAI_URL
$ heroku config:set ES_ENABLED=true ES_HOST= ES_PORT= ES_USER= ES_PASS=

Deploy

There are two ways to deploy.

You can either push this repo to heroku via git, triggering the heroku.yml manifest which will build the Docker image on heroku's servers and deploy it.

Or you can build the docker locally, and push it directly to heroku's container registry and then deploy it manually via the cli.

Simple way

Just push to heroku, to build container and deploy:

Note that migrations are run automatically using a release phase command.

$ git push heroku

Manual way

Build and push the container:

$ heroku container:push web

Build and push the release container, then trigger it to run migrations (optional):

$ heroku container:push release
$ heroku container:release release

Deploy the new frontend container:

$ heroku container:release web

Sidekiq

Start the number of background workers needed:

$ heroku ps:scale worker=1