page:recipes:asset library:rails:relational workflow
Host asset library with Rails: relational workflow state
Deploy a asset library built with Rails on Ample using the transactional workflows pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL. Verified on Rails: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Not separately tested: your domain records, validation rules and concurrency policy; treat the asset library-specific behavior as your application code.
Representative Queries
- Host asset library with Rails: relational workflow state
- Where can I host Asset library built with Rails?
- I need a domain record schema, validation rules and concurrency behavior.
Resource Requirements
primitive:computeprimitive:postgres
Infrastructure Requirements
- Compute: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
- Postgres: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.
Prerequisites
- A Rails project that builds and starts with the documented commands (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via
rails serverreading PORT on the ruby-3.4 template with RAILS_ENV=production) - A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
- An Ample account token with servers:write, databases:read
Workflow Steps
- Build and start: bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via
rails serverreading PORT on the ruby-3.4 template with RAILS_ENV=production. The server must bind 0.0.0.0 on PORT. - Implement the pattern on PostgreSQL: The fixture's module implements transactional workflows: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
- Deploy: Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op. Command:
ample deploy . --name --public - Verify: Fetch the live URL and the pattern self-test route(s) (/p/transactional-workflows) from the example; then run your own checks. On failure read
ample logs --kind buildthen--kind runtime. Command:ample logs --kind build
Example
- Title: Rails pattern fixture
- Description: Multi-pattern Rails app whose transactional workflows module was checked live; the module is under tests/deploy-canaries/_pattern-modules.
- Source Ref: tests/deploy-canaries/rails-patterns
Success Checks
- app responds on its public URL
- transactional-workflows self-test
Limitations
- Verified on the ruby-3.4 template at s-1vcpu-1gb with the example fixture; other sizes, templates, and Rails major versions are not verified.
- The asset library itself (your domain records, validation rules, and concurrency policy) is application code and was not separately tested; the pattern checks are what was verified.
Cost Estimate
- Currency: USD
- Monthly Amount: 10.0
- Note: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.