Railway: Deploy the NestJS API from GHCR The API follows the build-once path from Phase 33: Railway pulls the exact GHCR image tagged with the Git SHA. When Railway uses a Docker-image source, it skips its own source build so the artifact tested in CI is the artifact that runs.
GHCR sha image → Railway service → /health/ready → Traffic switch
Service rules • Source: exact GHCR image tag, not :latest
• Listen on 0.0.0.0 and process.env.PORT
• Healthcheck path: /health/ready
• Custom domain: api.taskflow.example.com with automatic TLS
Registry credentials • Private GHCR images require Railway private-registry support and a read-only package token.
• Do not reuse the CI token that has write:packages.
• A public image avoids registry credentials but may not suit a proprietary application.
# Container runtime concept
HOST=0.0.0.0
PORT=<injected by Railway>
NODE_ENV=production# Image identity ghcr.io/acme/taskflow-api:sha-<full-commit>
Railway health checks gate the new deployment before traffic is switched, but Railway documents that this healthcheck is deployment-time gating rather than continuous post-deploy monitoring.
Sources: Railway private registry deployment, service-source, domain, healthcheck, and rollback documentation.
Deployment is the controlled movement of a versioned artifact into a configured runtime with evidence of health and a credible rollback path.
Restate the goal of “Railway NestJS API Deployment” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: versioned artifact → production config → runtime → health/smoke test → rollback path. Mark the one boundary this lesson changes.
Inspect the current repository state and record the exact files, route, table, or runtime involved. Avoid creating an abstraction before you can name the existing owner.
Implement the smallest vertical slice. Add one coherent change, run the narrowest verification command, and read the output before continuing.
Connect the slice to TaskFlow’s phase artifact: Staging and production deployment runbooks with release identity, environment matrix, smoke tests, and rollback procedure.. Verify behavior from the outside as a user or API client would.
Create one controlled failure that is safe to reproduce. Predict the symptom first, capture evidence, locate the earliest broken boundary, then fix only that cause.
Close the reference and rebuild or explain the core change from memory. Record what you would monitor or test before trusting the same change in production.
1. Build an immutable artifact.
2. Apply production configuration/secrets.
3. Run compatible migrations.
4. Start the new version.
5. Check readiness and smoke tests.
6. Observe errors/latency.
7. Promote or execute rollback.Do not copy this as a finished answer. Predict what each boundary does, type the smallest useful slice, run it, then compare the result with your prediction.
Separate platform deploy status from application readiness; run smoke tests against real routes and dependencies.
Use expand/contract migrations and keep rollback compatibility explicit before release.
Without copying the final source, create a second small scenario that applies “Railway NestJS API Deployment” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Deploy the exact API container artifact and verify bind address, PORT, and readiness endpoint.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.Code deploy occurs before required migration or vice versa without compatibility plan
Predict the symptom before causing the failure. Then locate the earliest boundary where reality diverges from expectation.Why does this responsibility live here, what input does it trust, what output proves success, and what would go wrong if another layer owned it?
If your explanation is vague, repeat the boundary trace before moving on.Close the reference. Reproduce the core idea from memory or explain the exact request/data flow aloud. Then check your diff or notes for accidental shortcuts that bypass validation, authorization, error handling, or verification earned in earlier phases.