Ruby

A Ruby app deploys from its repository. Nimbus Land recognises it from your Gemfile, builds it and starts it, and for Rails fills in the settings a first deploy needs. Your own values always win.

Quick start#

A stock rails new app deploys as is. In the console, create an app from your repository with the deploy wizard. From the CLI, run this in the project directory:

nimbus deploy

Check these first:

• Your server listens on PORT. Puma and Rails already do. See what every app needs.
• If the app reads encrypted credentials, have your config/master.key ready to paste as RAILS_MASTER_KEY. See Rails.
• If the app uses SQLite, keep the storage volume the wizard offers, or every release starts with an empty database.

For non-Rails Ruby apps, RACK_ENV=production is suggested.

Rails#

A stock rails new app ships its own Dockerfile, and Nimbus Land builds from it. See Dockerfile. A Rails app without a Dockerfile is built by Nimbus Land directly. Either way, it fills in what a first deploy needs:

• RAILS_ENV and RACK_ENV are set to production when your image doesn't set them.

• SECRET_KEY_BASE is generated and stored on the app when neither it nor RAILS_MASTER_KEY is set, so a stock app boots and sessions survive redeploys.

• RAILS_MASTER_KEY appears in the wizard as an empty secret. Paste your local config/master.key only if the app reads encrypted credentials. It is required when the repository ships config/credentials.yml.enc (or config/credentials/production.yml.enc) and config/environments/production.rb sets config.require_master_key = true; the wizard then holds Deploy until it is filled. From the CLI:

  nimbus env set RAILS_MASTER_KEY=- --secret < config/master.key

  See Secret environment variables.

• Storage volume. A SQLite app keeps its databases under storage/. When the Gemfile names sqlite3 and neither pg nor mysql2, the wizard offers a 1 GB volume at /rails/storage (/workspace/src/storage when Nimbus Land builds the app itself). Keep it, or every release starts with an empty database. From the CLI or API, attach a volume at the same path yourself. An app with a volume stops the old instance before starting the new one, so a redeploy has a few seconds with nothing serving. See Volumes and SQLite databases.

• Background jobs. When the Gemfile names solid_queue, SOLID_QUEUE_IN_PUMA=true is suggested so queued jobs run. Alternatively, add the Solid Queue worker in the Background workers section of the Resources tab. See commands, workers and one-off runs.

• Migrations. The scaffold's entrypoint runs bin/rails db:prepare on every start. With Postgres, use the release command instead: the wizard suggests bundle exec rails db:migrate. See release command.

Troubleshooting#

For problems that aren't specific to Ruby, such as an app that never answers, see Apps troubleshooting.

Missing master key#

The app fails at start with Missing encryption key to decrypt file with. Add RAILS_MASTER_KEY as a secret on the Resources tab (the contents of config/master.key, or config/credentials/production.key) and deploy again.

ArgumentError: unknown keyword: quirks_mode#

A fresh Rails 8.0 app fails assets:precompile with this message. Add gem "json", "< 3" to the Gemfile, run bundle install, commit and deploy again.

The SQLite database is empty after a deploy#

The app has no volume at its storage/ path. Attach one as described under Rails.