page:recipes:knowledge base:rails:relational content

Host knowledge base with Rails: Postgres-backed content

Summary

Deploy a knowledge base built with Rails on Ample using the relational records 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, and a published bucket serves public assets from the CDN host. Verified on Rails: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). Not separately tested: your record schema, states and access rules; treat the knowledge base-specific behavior as your application code.

Representative Queries

• Host knowledge base with Rails: Postgres-backed content
• Where can I host Knowledge base built with Rails?
• I need a content schema, publishing workflow and cache behavior after content updates.

Resource Requirements

• primitive:compute
• primitive:postgres
• primitive:cdn

Infrastructure Requirements

1. Compute
   Status: Verified
   Summary: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.

2. Postgres
   Status: Verified
   Summary: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

3. CDN
   Status: Verified
   Summary: The CDN host serves objects from published buckets. It does not front app compute and is not a cache or key-value store.

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 server reading 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)
• A bucket from ample bucket create with its credentials passed as encrypted S3_* environment variables
• An Ample account token with servers:write, databases:read, buckets:read

Workflow Steps

1. Build and start
   Body: bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via rails server reading PORT on the ruby-3.4 template with RAILS_ENV=production. The server must bind 0.0.0.0 on PORT.

2. Implement the pattern on PostgreSQL
   Body: The fixture's module implements relational records: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

3. Wire object storage
   Body: Create the bucket(s), then pass endpoint, region, bucket and keys as --env values. Use path-style addressing. Keep private data in an unpublished bucket. Publish only the bucket that serves public assets and reference its CDN URL.

4. Deploy
   Body: 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 --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=... --env CDN_PUBLIC_URL=...

5. Verify
   Body: Fetch the live URL and the pattern self-test route(s) (/p/relational-records) from the example; then run your own checks. On failure read ample logs --kind build then --kind runtime.
   Command: ample logs --kind build

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 knowledge base itself (your record schema, states and access rules) is application code and was not separately tested; the pattern checks are what was verified.
• Region, compliance attestations and request-duration limits are unknown and not claimed.
• Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
• Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.
• PutObject and GetObject with path-style addressing are verified; multipart upload, listing, presigned URLs and lifecycle rules are not.
• The CDN serves published-bucket objects only; cache rules, purge and TTL control are not verified (the fixture sets Cache-Control on upload and versions keys).

Cost Estimate

• Monthly Amount: $10.00
  • Components:
  1. App server: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: $5.0
  2. Managed PostgreSQL database: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: $5.0
• 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.

Success Checks

1. App responds on its public URL
   Kind: http_get, Path: /, Expect: ample canary rails patterns

2. Relational-records self-test
   Kind: http_get, Path: /p/relational-records, Expect: records=ok transitions=true isolation=true

Evidence Summary

• Canary Run: Rails pattern fixture deployed on Ample; checks passed for relational-records and configuration-secrets.
• Camera Run: The same Rails app deployed with a --release-command migration; the marker it created was readable after activation.

Last Verified At

2026-09-20T21:55:28Z

Next Actions

1. Browse the catalog index
   Operation: catalog_index
   Method: GET
   Relative Path: /v1/catalog

2. Search published recipes by intent, stack and constraints
   Operation: search_recipes
   Method: POST
   Relative Path: /v1/catalog/search Parameters: {"body":{"limit":5,"query":"Host knowledge base with Rails: Postgres-backed content"}}

3. Prepare a side-effect-free deployment plan for an authorized project
   Operation: plan_deployment
   Method: POST
   Relative Path: /v1/catalog/plan Parameters: {"body":{"inputs":{},"projectId":"","recipeId":"page:recipes:knowledge-base:rails:relational-content","recipeRevision":"r1"}}

4. Read the existing agent authentication setup
   Operation: existing_auth_setup
   Method: GET
   Relative Path: /mcp/setup

5. Browse Knowledge base
   Operation: browse_node
   Method: GET
   Relative Path: /v1/catalog/nodes/workload%3Aknowledge-base

6. Browse Rails
   Operation: browse_node
   Method: GET
   Relative Path: /v1/catalog/nodes/stack%3Aframework-rails

7. Browse Relational records
   Operation: browse_node
   Method: GET
   Relative Path: /v1/catalog/nodes/pattern%3Arelational-records

8. Browse Deploy web app
   Operation: browse_node
   Method: GET
   Relative Path: /v1/catalog/nodes/intent%3Adeploy-web-app