# Operations runbook This runbook describes the commands that are implemented and verified in this repository. It does not claim a production recovery point objective, recovery time objective, retention period, storage capacity, or high-availability model; those values require product policy and measurements from the eventual production environment. ## Private Gitea continuous integration The observed private Git remote is hosted by Gitea 1.22.0. Gitea 1.22 reads repository workflows from `.gitea/workflows/`, so the repository keeps a Gitea-specific quality workflow in addition to the GitHub-compatible workflow. Both files are checked by the pinned local actionlint gate. The Gitea workflow deliberately targets only the custom `who-need-help-ci` runner label. Its jobs build and run many Docker images and must not be scheduled onto an unrelated shared runner or onto the production application host. Its gates run sequentially in one job so a single push cannot start four heavy Docker suites concurrently. Before enabling it: 1. enable Actions in the private repository settings; 2. register a trusted runner controlled by this project; 3. assign `who-need-help-ci:host` only to a Linux host where the exact Docker Engine and Compose commands used by the repository have been verified; 4. install the runtime required by the pinned checkout action on that host; 5. keep the runner registration state and any Docker socket access outside the repository and away from untrusted projects. The runner's availability, labels, software versions, free resources and repository Actions setting cannot be established from the unauthenticated repository clone. Do not treat the presence of the workflow file as evidence that remote CI has run. After provisioning the runner, trigger the workflow manually, require the full job and all four gate steps to pass, and record the run URL and commit before protecting `main`. ## First production Compose environment The deployment environment selects topology and database ownership: | Setting | Result | | --- | --- | | `APP_TOPOLOGY=compact` | One Phoenix+Oban container, directly published to the host; default for the first server. | | `APP_TOPOLOGY=split` | Traefik, `WEB_REPLICAS` web containers, and `WORKER_REPLICAS` worker containers. | | `DATABASE_MODE=container` | Start the project-owned PostgreSQL/PostGIS container and volume. | | `DATABASE_MODE=external` | Do not create/start a Compose database; use only `DATABASE_URL`. | There is no Redis dependency. Queues, rate-limit counters, Oban leadership, and durable application state use PostgreSQL. ### Two independent checkouts and one `.env` in each The server uses exactly these independent Git clones: ```text /srv/who_need_help-test/.env /srv/who_need_help-production/.env ``` No `.env.test`, `.env.staging`, `.env.production`, or `.env.edge` is used. Each checkout can remain on a different commit. Test and production have different Compose projects, application/infrastructure image tags, database connections, Docker volumes, public aliases, Google OAuth clients, email delivery paths, and generated secrets. Oban queues are isolated by those different PostgreSQL databases. There is no Redis dependency. The shared Caddy edge is owned only by the production checkout and reads the same production `.env`; it is not a third project directory or a second secret file. Both applications intentionally share only the external `who_need_help_public_edge` Docker network. Caddy routes `whoneedhelp.com` to `who-need-help-production:4000` and `test.whoneedhelp.com` to `who-need-help-test:4000`. Create the test configuration inside the test checkout: ```bash cd /srv/who_need_help-test TEST_CODEX_SESSION_ID=YOUR_MAIN_CODEX_SESSION_ID \ TEST_GOOGLE_OAUTH_CLIENT_ID=YOUR_TEST_CLIENT_ID \ TEST_GOOGLE_OAUTH_CLIENT_SECRET=YOUR_TEST_CLIENT_SECRET \ ./scripts/init-test-env.sh test.whoneedhelp.com ./scripts/validate-test-env.sh .env test.whoneedhelp.com ./scripts/deploy-up.sh .env ``` For later test updates, check out the desired clean revision and update only the image tags. Existing deployment secrets remain unchanged: ```bash ./scripts/set-deployment-revision.sh .env ./scripts/deploy-up.sh .env ``` Test always uses its own `who_need_help_test` PostGIS container/volume and Mailpit. Its messages cannot be sent by the production UniSender account. Create the production configuration inside the production checkout after loading only the production database/provider credentials into the process: ```bash cd /srv/who_need_help-production PRODUCTION_DATABASE_MODE=external \ PRODUCTION_DATABASE_URL='ecto://PRODUCTION_ROLE:PASSWORD@localhost/who_need_help_production' \ PRODUCTION_DATABASE_SOCKET_DIR=/var/run/postgresql \ PRODUCTION_EMAIL_DELIVERY_PROVIDER=unisender_go \ PRODUCTION_UNISENDER_GO_API_KEY=YOUR_PRODUCTION_KEY \ PRODUCTION_GOOGLE_OAUTH_CLIENT_ID=YOUR_PRODUCTION_CLIENT_ID \ PRODUCTION_GOOGLE_OAUTH_CLIENT_SECRET=YOUR_PRODUCTION_CLIENT_SECRET \ PRODUCTION_CODEX_SESSION_ID=YOUR_MAIN_CODEX_SESSION_ID \ ./scripts/init-production-env.sh whoneedhelp.com ./scripts/validate-production-env.sh .env whoneedhelp.com ``` Promote the exact revision already verified in test by checking out that SHA in the independent production clone, then update only the production image tags: ```bash git checkout --detach ./scripts/set-deployment-revision.sh .env ./scripts/deploy-up.sh .env ``` Before either public switch, prove cross-environment isolation without printing credentials: ```bash /srv/who_need_help-test/scripts/validate-deployment-isolation.sh \ /srv/who_need_help-test /srv/who_need_help-production ``` Start/update test first and run the complete browser/API/Android verification. Only then check out that exact tested SHA in production. Start the shared edge from the production checkout with `./scripts/edge-up.sh .env`; start the production application separately with `./scripts/deploy-up.sh .env`. `edge-up.sh` explicitly selects `EDGE_COMPOSE_PROJECT_NAME`, so the shared proxy remains independent from both application Compose projects even though the same production `.env` also contains `COMPOSE_PROJECT_NAME`. The authoritative A records for `whoneedhelp.com`, `www.whoneedhelp.com`, and `test.whoneedhelp.com` must point to the verified server address before Caddy can obtain their certificates. Do not remove the edge volumes during an ordinary application deploy. Do not add `--volumes` to a stop command unless the exact database has been inspected and deletion is intended. The initializer reads `.env.example`, derives the numeric group of that host's Docker socket, generates independent random values for PostgreSQL, `SECRET_KEY_BASE`, handover codes, the BEAM release cookie, and metrics access, and writes an ignored mode-`0600` file. It does not print those values and refuses to overwrite an existing destination. By default, the generated public proxy port binds to `127.0.0.1`, which is appropriate only when the verified reverse proxy reaches the application on the same host. Set `PRODUCTION_HTTP_BIND_ADDRESS` when generating the file, or edit `HTTP_BIND_ADDRESS` afterward, to match the observed target topology. Replace `TRAEFIK_TRUSTED_IPS` with the exact source IP/CIDR observed at Traefik; do not copy the temporary VPN value into an unrelated server. Configure the transactional email provider and a sender accepted by it. SMTP uses `EMAIL_DELIVERY_PROVIDER=smtp` plus the `SMTP_*` settings. UniSender Go's HTTPS Web API uses `EMAIL_DELIVERY_PROVIDER=unisender_go`, `UNISENDER_GO_API_KEY`, and the default documented API base URL. The initializer accepts the corresponding `PRODUCTION_EMAIL_DELIVERY_PROVIDER`, `PRODUCTION_SMTP_*`, and `PRODUCTION_UNISENDER_GO_*` inputs. Optional `EMAIL_HTTP_CONNECT_TIMEOUT_MS` and `EMAIL_HTTP_RECEIVE_TIMEOUT_MS` override the Req/Finch defaults only when deployment measurements justify explicit values. Set optional `SUPPORT_INBOX_ADDRESS` to a monitored address for support/removal queue alerts and email `Reply-To`; leaving it empty disables operator email alerts, not the protected queues. If Google registration/sign-in is enabled, also set both Google Web client credentials and register `https://YOUR_PHX_HOST/auth/google/callback` as the exact authorized redirect URI. Leave both credentials empty to keep the feature disabled. Then run: ```bash ./scripts/validate-production-env.sh .env whoneedhelp.com ./scripts/deploy-up.sh .env ``` The production override keeps Mailpit behind its inactive `local-mail` profile, so public registration cannot appear to succeed while mail is only retained locally. The validator checks file ownership/mode, origin consistency, template markers, independent generated secrets, settings required by the selected email provider, a complete-or-empty Google credential pair, the generated database URL, and the final Compose render without printing secrets. It does not contact DNS, TLS, the email provider, the reverse proxy, or the application. After deployment, verify `/healthz/ready`, inspect all replica health and logs, register a unique address through the public browser, receive its message at the real mailbox, follow the HTTPS confirmation link, and remove only that run-scoped account. ### External PostgreSQL/PostGIS #### PostgreSQL on the same Linux host The server-local mode uses the PostgreSQL Unix socket instead of exposing the database on a Docker-reachable TCP address. Ecto/Postgrex receive `DATABASE_SOCKET_DIR`; `scripts/compose.sh` then adds `compose.external-db-socket.yaml` and mounts that exact directory read-only into the active application and migration services. An empty setting preserves the normal remote-provider TCP behavior. After read-only inspection confirms the intended PostgreSQL 18 cluster, installed PostGIS package, socket directory, and absence of the project-scoped roles/databases, run the root-only provisioner: ```bash sudo ./scripts/provision-host-postgres.sh "$USER" ``` Its exact mutation scope is: - prepend two database-and-role-specific `local ... scram-sha-256` rules to the active `pg_hba.conf`, retaining a mode-`0600` copy under `/var/backups/who_need_help/`, and reload that cluster; - create login roles `wnh_production` and `wnh_test` without superuser, database-creation, role-creation, replication, or row-security bypass rights; - create empty owner databases `who_need_help_production` and `who_need_help_test`, revoke public connect, and preload `citext` and PostGIS so the non-superuser Ecto migrations can run; - verify both credentials through the observed Unix socket and write separate mode-`0600` initializer fragments under `~/.config/who_need_help/` without printing passwords. The command refuses to overwrite credential fragments, refuses any matching pre-existing role/database or managed HBA marker, validates the candidate HBA rules before reload, and restores its HBA backup plus removes only objects it created if provisioning fails. It does not inspect or migrate application tables; the release migration runner remains authoritative for schema. Generate test or production after loading only the matching trusted fragment: ```bash set -a . "$HOME/.config/who_need_help/database-production.env" set +a ./scripts/init-production-env.sh whoneedhelp.com unset PRODUCTION_DATABASE_MODE PRODUCTION_DATABASE_URL \ PRODUCTION_DATABASE_SOCKET_DIR ``` For test external-database drills, load `database-test.env`; the public test deployment normally uses its own Compose database. Do not load both fragments into one shell. Provision the database and role first, then generate the environment without placing its credentials on a command line that is retained in shell history: ```bash export PRODUCTION_DATABASE_MODE=external read -rsp 'External DATABASE_URL: ' PRODUCTION_DATABASE_URL && echo export PRODUCTION_DATABASE_URL ./scripts/init-production-env.sh whoneedhelp.com unset PRODUCTION_DATABASE_URL ``` Set `PRODUCTION_APP_TOPOLOGY=split` during generation when independent web and worker scaling is required. In external mode `scripts/compose-up.sh` builds the migration image, runs `scripts/check-database.sh`, and fails before migration or application startup unless PostgreSQL and `PostGIS_Version()` are reachable. The check also reports the observed TLS flag. The connection URL must follow the database provider's verified TLS/CA requirements. `scripts/compose.sh .env config --services` is the canonical read-only render check. In external mode its output must not contain `db`. Use `scripts/compose.sh .env ps -a` and `scripts/compose.sh .env logs web worker` for the selected mode. The repository's Compose backup, restore, rotation, and rollback-based staging scripts deliberately refuse `DATABASE_MODE=external`; they are scoped to the project-owned database container. For an external database, use the provider's verified backup/restore procedure and test recovery before public launch. ## Compose database backup Create a PostgreSQL 18 custom-format archive, validate its table of contents, and write a SHA-256 manifest: ```bash ./scripts/backup-compose.sh ``` The default destination is the ignored `output/backups/` directory. An explicit new destination may be supplied as the only argument. The command refuses to overwrite either an archive or its checksum manifest and writes through temporary files before publishing the final pair. Files and newly created directories are restricted by `umask 077`. The archive covers the configured application database. PostgreSQL cluster globals such as roles and tablespaces are not part of `pg_dump`; deployment credentials and database roles must be provisioned separately from secrets. Local backup files on the same workstation are not an off-site backup. ## Encrypted local S3-compatible backup drill The isolated load project can run a complete encrypted Restic/MinIO drill: ```bash ./scripts/load-stack-up.sh ./scripts/backup-s3-drill.sh local-encrypted-backup ``` The script refuses the staging Compose project and validates the project and service labels of every pre-existing container in its scope. On first use, `scripts/ensure-local-load-env.sh` generates independent random MinIO and Restic credentials in ignored `.env.load` and restricts that file to mode `0600`. MinIO publishes Docker-assigned ports only on `127.0.0.1`; the observed API and console URLs are printed after a successful run. The backup tool combines the matching PostgreSQL 18 client with pinned Restic rebuilt on Go 1.26.5. MinIO server and client are also rebuilt as non-root Alpine images from checksum-pinned upstream source commits with the exact dependency updates recorded in `Dockerfile.minio`. The quality gate verifies their reported release, commit, Go runtime, configured user, and current HIGH/CRITICAL vulnerability scan. `restic backup --stdin-from-command` runs a custom-format `pg_dump`, checks the producer exit status, encrypts the data, and uploads it directly to MinIO. No plaintext database dump is written to the host. The drill then: 1. runs `restic check --read-data`; 2. streams `restic dump` into `pg_restore --list`; 3. restores into a uniquely named database created from `template0`; 4. checks tables, current Ecto migrations, PostGIS, and release migration readiness before removing that exact database; 5. clones and corrupts an isolated repository and requires both check and dump to fail; 6. stops an exact scoped in-progress backup container only after encrypted objects reach MinIO, requires zero published snapshots, prunes unreferenced packs, and rechecks the repository; 7. removes and verifies removal of the corruption/interruption buckets and requires source table counts to remain unchanged. The successful encrypted bucket is deliberately retained in the named local MinIO volume. Non-secret evidence is written under ignored `output/backups-s3//`; the runtime scratch directory is under ignored `tmp/backup-s3/`. Use a unique lowercase run label of at most 32 characters. The command refuses to replace an existing retained bucket. MinIO server and client are AGPLv3. `Dockerfile.minio` identifies the exact upstream source commits and contains the dependency changes and complete build commands used here. Before distributing or publicly operating modified images, review the license and make the corresponding source available as required; this runbook does not provide legal advice. This verifies encryption, local S3 protocol use, restore mechanics, and two failure paths on the observed workstation. A MinIO volume on that same workstation is not an off-site backup and does not establish production RPO, RTO, retention, capacity, key custody, object locking, or database HA. ## Local external-service boundary drill Run the OAuth, SMTP, and provider-neutral push protocol checks without public credentials, a server, or host-published ports: ```bash ./scripts/external-boundaries-run.sh local-boundaries ``` The script creates a uniquely named Compose project on an internal-only Docker network. It generates independent one-run OAuth and push credentials in an ignored mode-`0600` environment file, including a separate bearer token for the protected metrics endpoint, builds the production release plus a non-root standard-library Python protocol mock, and then verifies: `compose.external-boundaries.yaml` is the only deployment file that sets `ALLOW_INSECURE_EXTERNAL_HTTP=true`. Ordinary runtime configuration requires HTTPS for OAuth and push endpoints so provider credentials are not sent over plain HTTP. 1. GitHub-compatible OAuth authorization, PKCE S256, token exchange, normalized user lookup, state mismatch, provider rejection, one-time-code replay, a fresh flow after a temporary token error, and a token timeout; 2. SMTP acceptance, permanent recipient rejection without retry, one retry after a temporary greeting failure, a greeting timeout, and the result of submitting the same message twice; 3. the disabled default push boundary plus HTTP success, permanent rejection, one temporary retry, replay deduplication, and deduplication after an ambiguous timeout using the same idempotency key; 4. a fresh PostGIS database, current migrations, and two Oban worker replicas; request acceptance and new-chat domain transactions enqueue stable user-recipient events, replay is deduplicated before HTTP, an injected temporary chat delivery fails its first Oban attempt and completes on its second, and private message text is absent from the push payload. The evidence JSON and mock state contain counters, booleans, normalized identity fields, payload digests, run-scoped user/event identifiers, and the privacy-safe notification metadata asserted by the drill. The script fails if any generated secret appears in retained evidence. Its trap validates exact Compose labels, removes only that project, volumes and one-run images, and deletes the temporary credential file. Failure logs are retained under the same ignored evidence directory. This drill uses the application's real Assent/Req and Swoosh/gen_smtp clients, but the providers are local. It therefore verifies client-side protocol and product integration, not GitHub, SMTP-provider, FCM, or APNs availability. SMTP permits duplicate delivery after ambiguous outcomes, so the result explicitly makes no exactly-once claim. Push currently targets a stable `user:` recipient; selecting a provider, registering device tokens, and resolving that user to devices remain deployment/provider work. The implementation follows the configured adapter interfaces and protocol semantics documented by [Assent 0.3.1](https://hexdocs.pm/assent/0.3.1/Assent.HTTPAdapter.html), [GitHub OAuth](https://docs.github.com/en/apps/oauth-apps/building-oauth-apps/authorizing-oauth-apps), and [SMTP RFC 5321](https://datatracker.ietf.org/doc/html/rfc5321). The optional `WhoNeedHelp.Email.UnisenderGoAdapter` maps the same Swoosh email objects to UniSender Go's documented JSON contract, supplies a per-delivery idempotence key, redacts rejected recipient addresses from returned errors, and uses only HTTPS. The provider documents the endpoint, `X-API-KEY` header, response shape, and one-minute/64-character idempotence-key behavior in its [Web API reference](https://godocs.unisender.ru/web-api-ref). Every request explicitly sets `track_links` and `track_read` to `0`; UniSender Go otherwise enables both by default and may require account-level approval before it honors those values. `UNISENDER_GO_SKIP_UNSUBSCRIBE` defaults to `false` and must remain disabled until UniSender Go support explicitly enables that transactional capability for the account. After approval, set it to `true` to add `skip_unsubscribe=1` to the provider request. Verify a delivered message's raw HTML after the provider confirms the account change and before launch. ## Isolated restore drill Run a real restore into a uniquely named temporary database: ```bash ./scripts/restore-drill-compose.sh output/backups/compose-YYYYMMDD-HHMMSS.dump ``` The drill: 1. validates the SHA-256 manifest; 2. validates the archive table of contents; 3. creates a pristine database from `template0`; 4. restores with `pg_restore --exit-on-error`; 5. reads every restored public application table and checks the PostGIS library; 6. runs the current immutable release's migrations and migration-readiness check against only the temporary database; 7. drops only the temporary drill database and verifies that it is gone. A trap also attempts to drop the exact temporary database if a check fails. The source application database is never passed to `pg_restore`, `dropdb`, a clean operation, or the drill migration runner. The drill intentionally does not compare an older backup's row counts to the live source, because concurrent legitimate writes or a historical archive would make that comparison invalid. ## Isolated Compose upgrade rehearsal After creating a current custom-format backup, run the complete current release against an isolated restored copy: ```bash ./scripts/upgrade-rehearsal-compose.sh \ output/backups/compose-YYYYMMDD-HHMMSS.dump ``` The rehearsal validates the checksum and archive catalog, reads the public origin configuration from ignored `.env`, and uses only the independently generated credentials in ignored mode-`0600` `.env.e2e`. It builds a uniquely tagged production release, creates a uniquely named Compose project and database from `template0`, restores the archive, records application-table counts, and then: 1. applies every current timestamped Ecto migration; 2. requires the localized category column and all 11 valid cursor indexes; 3. starts 2 web and 2 worker replicas behind the isolated Traefik instance; 4. requires the four-node BEAM cluster and cross-node PubSub probe; 5. checks the production HTTP-to-HTTPS redirect, trusted-proxy public pages, and both health endpoints; 6. requires an empty before/after diff for every public application table except the expected migration and Oban-internal tables; 7. removes and verifies removal of the exact containers, networks, database volume, and one-run image. The input archive is read-only and is not copied into the evidence directory. The ordinary Compose project, source database, public route, and running containers are outside the generated project scope. Non-secret evidence is retained under ignored mode-`0700` `output/upgrade-rehearsal//`, with files mode `0600`. ## Clean tracked-revision deployment drill Run: ```bash ./scripts/clean-deploy-verify.sh ``` The script archives the current tracked Git revision into a new temporary directory. It verifies that the archive contains no local `.env`, Git metadata, generated output, or existing E2E/load environment. It generates independent one-run PostgreSQL, Phoenix, handover, BEAM-cookie, and metrics secrets with mode `0600`; optional GitHub OAuth and push delivery stay disabled. The drill uses a unique Compose project, application image, router/service name, internal network, PostgreSQL volume, database, and dynamic host ports. It requires exactly two healthy web and two running worker replicas, all tracked migrations, seeded categories, an idempotent repeated migration, working readiness/home/registration/Mailpit routes, four connected BEAM nodes, and a cross-replica PubSub message. It then removes the exact project including volumes, its one-run image, and the temporary archive, and verifies that those scoped resources are absent. Evidence is retained under `output/portability//`. This is a local Docker portability observation. It does not establish production SMTP, OAuth, push-provider, TLS, database-HA, storage, capacity, or jurisdictional readiness. ## Service checks ```bash docker compose ps curl --fail http://localhost:4010/healthz/live curl --fail http://localhost:4010/healthz/ready ./scripts/verify-realtime-cluster.sh compose ``` `live` verifies that the web process can serve HTTP. `ready` additionally runs `SELECT 1` through the configured Ecto repository. The cluster probe subscribes on one connected BEAM node and broadcasts from another. Health checks do not replace alerting, database backups, restore drills, or application-level synthetic checks. ## Local failure and rolling-replacement drills The isolated load project can exercise process crashes, sequential container replacement, and a real Oban retry without touching the normal Compose project: ```bash ./scripts/load-stack-up.sh ./scripts/load-resilience-run.sh local-resilience ``` The resilience script refuses `LOAD_PROJECT=who_need_help` and verifies the Compose project/service labels of every container before stopping it. It: 1. continuously calls readiness through the isolated Traefik route; 2. terminates the BEAM process in one web and one worker container and requires Docker's observed restart count to increase; 3. removes and replaces each web and worker replica one at a time; 4. waits for every configured BEAM node, then runs the cross-node PubSub probe; 5. enqueues a side-effect-free local worker that fails its first Oban attempt and succeeds on its second; 6. removes that exact Oban row and requires no fixture domain rows to remain. Traefik's retry middleware is attached to the HTTP and local TLS routers. Its attempt count is an environment input. Traefik retries transport failures and, with the checked configuration, does not opt in to retrying non-idempotent requests. This reduces a stale-backend window; it is not a claim of production availability. For the project-owned kind cluster, run: ```bash ./scripts/kind-rolling-verify.sh local-kind-rollout ``` The kind control plane is an optional verification environment, not part of the ordinary public Compose route. Pause it without deleting its container or Kubernetes state when the cluster is not being tested: ```bash ./scripts/kind-stop.sh ``` The next `./scripts/kind-up.sh` validates the ownership marker and kind labels, starts the stopped control plane, then continues with image loading and chart reconciliation. That script requires both the kind ownership marker and the control-plane cluster label before invoking `rollout restart`. It changes only the web and worker Deployment pod templates. It snapshots application-table counts before and after, continuously probes the observed Docker mapping for the chart's NodePort, requires all four old pod UIDs to disappear, waits for the exact BEAM peer count, and verifies cross-node PubSub. PostGIS, its hostPath, the Kubernetes Secret, and the namespace are not recreated. The rollout timeout, probe interval/timeout/retry count, and cluster-join timeout are experiment inputs. They are not production SLOs or resource requirements. ## Isolated Oban burst measurement The worker role consumes only `maintenance` and `push`. Configure their per-worker limits with `OBAN_MAINTENANCE_CONCURRENCY` and `OBAN_PUSH_CONCURRENCY`; multiplying either value by the number of worker replicas gives the configured cluster-wide concurrency for that queue. After starting the isolated load project, run an explicitly sized experiment: ```bash ./scripts/load-stack-up.sh ./scripts/oban-burst-run.sh local-oban-burst 1000 120 ``` The three required arguments are an evidence label, job count, and recorded experiment timeout in seconds. They are not capacity thresholds. The script refuses the ordinary `who_need_help` project, verifies the expected worker replicas, inserts only confirmed `LocalBurstProbe` jobs with a unique run id, records each worker's effective queue configuration and container samples, requires every job to complete, compares domain-table row counts, and deletes exactly its own jobs. The probe worker has no product side effects and no product flow enqueues it. ## Kubernetes ingress isolation `networkPolicy.enabled=true` renders the chart's ingress NetworkPolicy. Enforcement is a property of the cluster CNI, not of the YAML object alone. Before relying on it, verify that the target cluster uses a NetworkPolicy- capable plugin and run positive HTTP/cluster checks plus negative blocked-port checks there. Egress remains intentionally unrestricted until the actual database and external-service destinations are known. ## BEAM runtime memory guard Compose sets `ERL_ZFLAGS="+Q ${ERLANG_PORT_LIMIT}"`; Helm renders the same flag from `app.erlangPortLimit`. Both default to `65536`, OTP's normal port-table limit. This makes the runtime independent of an unusually large host or nested container `nofile` limit. Validate all live replicas after deployment: ```bash ./scripts/verify-beam-runtime.sh compose ./scripts/verify-beam-runtime.sh kind ``` The command records the effective port count/limit, allocated port-table bytes, BEAM memory, process count, cgroup memory, and RSS for each web and worker replica. It fails when a live VM does not use the configured limit; kind mode also requires the desired number of Ready application pods. `65536` is a concurrency ceiling for simultaneously existing Erlang ports (files, sockets, and drivers), not a container memory limit. Do not lower or raise it from a RAM estimate alone. A changed value must be validated against measured peak port usage and the target environment. ## Protected Prometheus metrics The web role exposes Prometheus text format at `/metrics`. It requires the independent `METRICS_TOKEN` deployment secret: ```bash curl --fail \ --header "Authorization: Bearer $METRICS_TOKEN" \ http://localhost:4010/metrics ``` The endpoint returns `401` without the exact token, disables response caching, and does not put the credential in a URL. The reporter exports cumulative HTTP request and duration, router exception, database query and duration, WebSocket connection, VM memory, and scheduler run-queue metrics. Cumulative durations are integer microseconds because the selected reporter's sum accumulator is integer-based; divide by `1_000_000` in PromQL when seconds are required. Definitions intentionally have no request path, user, request, or event-name labels that could create unbounded cardinality. Metrics are local to each BEAM process. Discover and scrape every web pod or container as a distinct target and preserve Prometheus's `instance` label. A request through the load-balanced public route reaches only one replica and is therefore useful as an authorization/smoke check, not as a cluster-wide aggregate. The isolated load project includes a local observability profile: ```bash ./scripts/load-stack-up.sh ./scripts/observability-run.sh local-observability ``` The run script refuses the staging project, validates every current web container's Compose labels, and writes a `file_sd` target for each observed internal IP. Prometheus reads the Bearer value from a mode-`0600` runtime file, not a tracked config or URL. Its direct request includes the internal `X-Forwarded-Proto: https` signal required by the application's production SSL rewrite while preserving the target's own `instance` label. Prometheus, Alertmanager, and Grafana are pinned by tag and digest. Their host ports default to Docker-assigned values bound only to `127.0.0.1`; the run prints the observed URLs. Grafana uses the random admin password generated in ignored `.env.load`, disables anonymous signup, update checks, suggested plugin installation, and its unused built-in alert engine. The Prometheus datasource and ten-panel dashboard are provisioned from tracked files. The dashboard separates all discovered web and worker replicas and includes HTTP traffic/latency, BEAM memory and scheduler run queues, Ecto execution and pool-wait latency, and Oban outcomes and queue wait by queue. The verification stops exactly one scoped load web container. The `WhoNeedHelpWebReplicaUnavailable` rule is based only on the factual `up == 0` result; it is a local failure drill, not an invented latency, capacity, or production SLO threshold. The script requires both firing and resolved webhook payloads from Alertmanager, starts the same container, waits for every direct target, and compares read-only database counts before and after. Evidence is retained in `output/observability/` without the metrics or Grafana secrets. Stop only the monitoring services with: ```bash ./scripts/observability-stop.sh ``` Prometheus/Grafana/Alertmanager retention, production notification destinations, production availability, and measured alert policies remain deployment decisions. In Kubernetes, put the metrics token in `existingSecret`; configure the external scraper to send it as a Bearer token. ## Rollback boundary The release image is immutable and migrations run as a separate one-shot role. Before a schema rollout, create and restore-test a current backup. Application rollback and database migration rollback are separate decisions: do not run an Ecto down migration merely because an image is rolled back. Inspect the exact migration and compatibility boundary first. The repository intentionally does not ship an automatic destructive production restore command.