82 lines
5 KiB
Markdown
82 lines
5 KiB
Markdown
# ${REPO_NAME}
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Express 5 + TypeScript backend generated from `nholtware/service-template-express`.
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## Endpoints
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- `GET /healthz` liveness, always 200 once listening
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- `GET /readyz` readiness: Postgres `SELECT 1` and Redis `PING` for whichever of `DATABASE_URL` / `REDIS_URL` are set; 503 + JSON reason otherwise
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- `GET /` service name, version (git sha), pod, `greeting` (runtime config), a `service_info` row, Redis hit counter, and `banner` while the `hello-banner` flag is on
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- `GET /admin/runtime-config` current runtime config `values`, `loadedAt`, `source` (`file` | `defaults`)
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- `GET /log-demo?msg=...` logs `{ demo: true, text }` with message `log-demo` (logging-pipeline demo; delete when you don't need it)
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## Local dev
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```sh
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cp .env.example .env # then export the vars, or use your shell's env loader
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npm ci && npm run dev
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npm run lint && npm test
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```
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Env is validated at boot (`src/lib/config.ts`): `PORT`, `SERVICE_NAME` (required), `LOG_LEVEL`, `DATABASE_URL?`, `REDIS_URL?`, `UNLEASH_URL?`, `UNLEASH_API_TOKEN?` (required with `UNLEASH_URL`), `UNLEASH_REFRESH_MS` (default 5000), `RUNTIME_CONFIG_PATH?`.
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Migrations: SQL files in `migrations/`, applied with `npm run migrate`.
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Logs: one JSON object per line on stdout (`level,time,msg,service,version`, plus `req.*`/`res.statusCode`/`responseTime` per request).
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## Seeing your logs
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Every container's stdout is shipped to Elasticsearch by Fluent Bit; nothing to configure per service.
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1. Open Kibana: https://kibana.lab.holtlabs.xyz, user `elastic`, password from
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`kubectl get secret -n logging logging-es-elastic-user -o jsonpath='{.data.elastic}' | base64 -d`.
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2. **Discover**, data view `kube-*` (the default).
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3. Query with KQL, e.g. `service:"${REPO_NAME}" and demo:true`, or `service:"${REPO_NAME}" and level:"error"`.
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Any field you pass to the logger becomes a queryable field:
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`req.log.info({ orderId }, "order placed")` → KQL `orderId:123`. The message string always
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overrides a `msg` key in the object, so don't name a field `msg`. Lines are searchable within a few seconds;
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retention is 14 days.
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## Feature flags
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Flags come from Unleash (UI: https://unleash.lab.holtlabs.xyz, environment `development`).
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`src/lib/flags.ts` wraps the official `unleash-client` SDK; routes get it as `deps.flags`:
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```ts
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if (deps.flags?.isEnabled("my-flag", { userId })) { ... }
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const v = deps.flags?.getVariant("my-experiment"); // v.name, v.enabled, v.payload
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```
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- In the cluster the deployment sets `UNLEASH_URL=http://unleash.unleash.svc:4242/api` and
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`UNLEASH_API_TOKEN` from Secret `unleash-client-token` (key `token`) in the service's namespace.
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- The SDK polls every 5 s; flipping a flag in the UI changes behaviour within seconds, no redeploy.
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- With `UNLEASH_URL` unset (local dev, tests) every flag reads `false` and one log line says so.
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If Unleash is down, flags keep their last fetched value (or `false`) and the service keeps serving.
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- Create the flag in the Unleash UI (project `default`) before using it; unknown flags read `false`.
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- Tests: pass a fake `Flags` to `createApp` (see `src/app.test.ts`); never hit a real Unleash.
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- `hello-banner` on `GET /` is the platform demo flag; delete it when you don't need it.
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## Runtime config
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Typed values you change with a git commit, live in running pods without a restart
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(timeouts, limits, copy; not on/off-for-whom, that's a feature flag; never secrets).
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- Schema + defaults: `src/runtime-config.schema.ts` (zod). Every key needs a default.
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- Read it per request: `deps.runtimeConfig.get().maxItems`. React to changes with
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`runtimeConfig.onChange((values, changedKeys) => ...)`.
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- In the cluster: ConfigMap `<app>-runtime-config` (key `runtime.yaml`) in gitops
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`manifests/<app>/runtime-config.yaml`, mounted as a directory at `/etc/app/`,
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`RUNTIME_CONFIG_PATH=/etc/app/runtime.yaml`. Edit, commit, push: live within ~4 min
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(ArgoCD polls every 3 min, kubelet refreshes the volume within ~1 min).
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Log line `runtime config reloaded` lists `changedKeys`.
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- A bad value (invalid YAML, fails the schema) keeps the last good values and logs `error`
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with the zod issues. The pod never crashes on a config commit. Fix it with another commit.
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- Local dev: `RUNTIME_CONFIG_PATH=./runtime.yaml npm run dev`; edits reload immediately.
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Unset = schema defaults (`source: "defaults"`).
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- `GET /admin/runtime-config` is unauthenticated, which is why nothing secret goes in here.
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## Using this template
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1. **Generate** a repo from this template in Forgejo (public). The repo name is substituted into `package.json`, this README, `.env.example`, and the first migration (CI derives the app name from the repo name itself).
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2. **Set 3 Actions secrets** on the new repo: `REGISTRY_USER` (`nholtware`), `REGISTRY_TOKEN` (registry push token), `GITOPS_TOKEN` (ci-bot gitops token).
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3. **Add gitops entries**: render `templates/backend/` (see its README) into `manifests/<app>/` and add `apps/<app>.yaml` in `nholtware/gitops`.
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4. **Push** to `main`. Generating a repo emits no push event, so CI only starts on your first push.
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