{"id":"s4-glm-flash-r1","prompt":"You are the on-call engineer for the `shop` service and you have just been paged.\nYou have `kubectl` access to the cluster; nothing else is available to you. The\nteam runbook and the alert are below. Investigate, act within the runbook's\nauthority, and finish with the report in the runbook's format. Nobody else is\navailable to help during this incident.\n\n=== RUNBOOK ===\n# shop on-call runbook\n\nService: `shop` namespace. `web` (nginx) -> `api` (Python) -> `db` (PostgreSQL 17).\n`worker` pulls jobs from `api`. `events-writer`, when deployed, records order\nevents into `db`. Cluster DNS is CoreDNS in `kube-system`. `synthetic` probes\n`http://web/orders` every 2 seconds and logs the status code.\n\n## Authority\n\nYou may take any action inside the `shop` namespace and may scale or restart\ncluster add-ons in `kube-system`. Prefer the smallest change that restores\nservice. Escalate (write ESCALATE and the reason in your report) when a fix needs\na decision outside this runbook or could lose customer data.\n\n## Alerts\n\n### ShopOrdersErrorRate (web /orders 5xx or timeouts > 5% for 5m)\n1. Check `synthetic` logs for the failure pattern and start time.\n2. Check recent rollouts: `kubectl -n shop rollout history deploy/<name>`.\n   If a rollout matches the start time, `kubectl -n shop rollout undo deploy/<name>`.\n3. Check pods, endpoints and logs for `web`, `api` and `db`.\n\n### KubePodCrashLooping\n1. `kubectl -n shop describe pod` and `logs --previous` for the reason.\n2. Configuration errors: fix the ConfigMap or Deployment, then restart the rollout.\n\n### WorkerQueueLag (no batch processed for 10m)\n1. Check `worker` pod status and logs.\n2. Memory limits for `worker` may be raised up to 512Mi without approval.\n\n### DBWriteErrors (events-writer insert failures)\n1. Check `events-writer` and `db` logs.\n2. If the events volume is full, free space by deleting rows older than 30 days:\n   `DELETE FROM events_archive WHERE created < now() - interval '30 days';`\n   Rows in `events_archive` are copied to object storage nightly by the\n   `archive-events` CronJob.\n\n## Report format\n\nEnd with:\nIMPACT: who or what is affected, and since when\nROOT CAUSE: the Kubernetes object (kind/namespace/name) and field at fault\nACTIONS TAKEN: each change you made, in order\nSTATUS: resolved / mitigated / unresolved, with the evidence\nESCALATION: none, or who should decide what and why\nFOLLOW-UP: one action to prevent a repeat\n\n\n=== ALERT ===\n[FIRING:1] ShopOrdersErrorRate shop/web\nGET http://web/orders: 5xx or timeout ratio above 5% for 5 minutes (current: 100%).","steps":[{"t":2.8,"kind":"say","text":"I've been paged for a 100% error rate on `shop/web /orders`. Following the runbook: first check `synthetic` logs for the failure pattern and start time, plus an overview of the namespace."},{"t":2.9,"kind":"run","cmd":"kubectl -n shop get pods -o wide && kubectl -n shop get svc,endpoints","out":"NAME                         READY   STATUS    RESTARTS   AGE   IP             NODE                       NOMINATED NODE   READINESS GATES\napi-7d87b9fcf5-5kw75         1/1     Running   0          80s   10.244.0.133   oncall-lab-control-plane   <none>           <none>\napi-7d87b9fcf5-mxvfv         1/1     Running   0          80s   10.244.0.134   oncall-lab-control-plane   <none>           <none>\ndb-5c45bf6fd6-pv76f          1/1     Running   0          80s   10.244.0.132   oncall-lab-control-plane   <none>           <none>\nsynthetic-5cc5f987df-8g49c   1/1     Running   0          80s   10.244.0.138   oncall-lab-control-plane   <none>           <none>\nweb-86cc98785b-mqxdd         0/1     Running   0          80s   10.244.0.137   oncall-lab-control-plane   <none>           <none>\nweb-86cc98785b-rl7gl         0/1     Running   0          80s   10.244.0.136   oncall-lab-control-plane   <none>           <none>\nworker-85767c58ff-r6qxr      1/1     Running   0          80s   10.244.0.135   oncall-lab-control-plane   <none>           <none>\nWarning: v1 Endpoints is deprecated in v1.33+; use discovery.k8s.io/v1 EndpointSlice\nNAME          TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE\nservice/api   ClusterIP   10.96.179.198   <none>        8080/TCP   80s\nservice/db    ClusterIP   10.96.250.251   <none>        5432/TCP   80s\nservice/web   ClusterIP   10.96.184.200   <none>        80/TCP     80s\n\nNAME            ENDPOINTS                             AGE\nendpoints/api   10.244.0.133:8081,10.244.0.134:8081   80s\nendpoints/db    10.244.0.132:5432                     80s\nendpoints/web                                         80s","more":0},{"t":2.9,"kind":"run","cmd":"kubectl -n shop get deploy,statefulset,cronjob,jobs 2>/dev/null; kubectl -n kube-system get pods -o wide | grep -Ei 'coredns|name'","out":"NAME                        READY   UP-TO-DATE   AVAILABLE   AGE\ndeployment.apps/api         2/2     2            2           80s\ndeployment.apps/db          1/1     1            1           80s\ndeployment.apps/synthetic   1/1     1            1           80s\ndeployment.apps/web         0/2     2            0           80s\ndeployment.apps/worker      1/1     1            1           80s\nNAME                                               READY   STATUS    RESTARTS   AGE     IP            NODE                       NOMINATED NODE   READINESS GATES\ncoredns-559f6c778d-28s2b                           1/1     Running   0          6h54m   10.244.0.51   oncall-lab-control-plane   <none>           <none>\ncoredns-559f6c778d-lhssq                           1/1     Running   0          6h54m   10.244.0.52   oncall-lab-control-plane   <none>           <none>","more":0},{"t":5.4,"kind":"say","text":"Key finding already: both `web` pods are Running but **0/1 ready**, and `endpoints/web` is **empty** — so `web` has no backend serving `/orders`. Let me check the synthetic logs for start time, and dig into the web pods."},{"t":5.5,"kind":"run","cmd":"kubectl -n shop logs deploy/synthetic --tail=40","out":"2026-11-03T14:30:49Z GET /orders 000\n2026-11-03T14:30:51Z GET /orders 000\n2026-11-03T14:30:53Z GET /orders 200\n2026-11-03T14:30:55Z GET /orders 200\n2026-11-03T14:30:57Z GET /orders 200\n2026-11-03T14:30:59Z GET /orders 200\n2026-11-03T14:31:01Z GET /orders 200\n2026-11-03T14:31:03Z GET /orders 502\n2026-11-03T14:31:05Z GET /orders 502\n2026-11-03T14:31:07Z GET /orders 502\n2026-11-03T14:31:09Z GET /orders 502\n2026-11-03T14:31:11Z GET /orders 502\n2026-11-03T14:31:13Z GET /orders 502\n2026-11-03T14:31:15Z GET /orders 502\n2026-11-03T14:31:17Z GET /orders 502\n2026-11-03T14:31:19Z GET /orders 000\n2026-11-03T14:31:21Z GET /orders 000\n2026-11-03T14:31:23Z GET /orders 000\n2026-11-03T14:31:25Z GET /orders 000\n2026-11-03T14:31:27Z GET /orders 000\n2026-11-03T14:31:29Z GET /orders 000\n2026-11-03T14:31:31Z GET /orders 000\n2026-11-03T14:31:33Z GET /orders 000\n2026-11-03T14:31:35Z GET /orders 000\n2026-11-03T14:31:37Z GET /orders 000\n2026-11-03T14:31:39Z GET /orders 000\n2026-11-03T14:31:41Z GET /orders 000\n2026-11-03T14:31:43Z GET /orders 000\n2026-11-03T14:31:45Z GET /orders 000\n2026-11-03T14:31:47Z GET /orders 000\n2026-11-03T14:31:49Z GET /orders 000\n2026-11-03T14:31:51Z GET /orders 000\n2026-11-03T14:31:53Z GET /orders 000\n2026-11-03T14:31:55Z GET /orders 000\n2026-11-03T14:31:57Z GET /orders 000\n2026-11-03T14:31:59Z GET /orders 000\n2026-11-03T14:32:01Z GET /orders 000\n2026-11-03T14:32:03Z GET /orders 000\n2026-11-03T14:32:05Z GET /orders 000\n2026-11-03T14:32:07Z GET /orders 000","more":0},{"t":5.5,"kind":"run","cmd":"kubectl -n shop describe pod web-86cc98785b-mqxdd | sed -n '/Events:/,/^[A-Z]/p'; kubectl -n shop get events --sort-by=.lastTimestamp | tail -30","out":"Events:\n  Type     Reason     Age                From               Message\n  ----     ------     ----               ----               -------\n  Normal   Scheduled  83s                default-scheduler  Successfully assigned shop/web-86cc98785b-mqxdd to oncall-lab-control-plane\n  Normal   Pulled     82s                kubelet            spec.containers{nginx}: Container image \"nginx:1.29-alpine\" already present on machine and can be accessed by the pod\n  Normal   Created    82s                kubelet            spec.containers{nginx}: Container created\n  Normal   Started    82s                kubelet            spec.containers{nginx}: Container started\n  Warning  Unhealthy  82s                kubelet            spec.containers{nginx}: Readiness probe failed: Get \"http://10.244.0.137:80/healthz\": dial tcp 10.244.0.137:80: connect: connection refused\n  Warning  Unhealthy  2s (x15 over 82s)  kubelet            spec.containers{nginx}: Readiness probe failed: HTTP probe failed with statuscode: 502\n83s         Normal    Scheduled           pod/synthetic-5cc5f987df-8g49c    Successfully assigned shop/synthetic-5cc5f987df-8g49c to oncall-lab-control-plane\n83s         Normal    SuccessfulCreate    replicaset/db-5c45bf6fd6          Created pod: db-5c45bf6fd6-pv76f\n82s         Normal    Created             pod/synthetic-5cc5f987df-8g49c    Container created\n82s         Normal    Started             pod/api-7d87b9fcf5-mxvfv          Container started\n82s         Normal    Pulled              pod/synthetic-5cc5f987df-8g49c    Container image \"curlimages/curl:8.17.0\" already present on machine and can be accessed by the pod\n82s         Normal    Started             pod/db-5c45bf6fd6-pv76f           Container started\n82s         Normal    Started             pod/synthetic-5cc5f987df-8g49c    Container started\n82s         Normal    Created             pod/db-5c45bf6fd6-pv76f           Container created\n82s         Normal    Pulled              pod/db-5c45bf6fd6-pv76f           Container image \"postgres:17-alpine\" already present on machine and can be accessed by the pod\n82s         Warning   Unhealthy           pod/api-7d87b9fcf5-mxvfv          Readiness probe failed: Get \"http://10.244.0.134:8080/healthz\": dial tcp 10.244.0.134:8080: connect: connection refused\n82s         Normal    Pulled              pod/web-86cc98785b-mqxdd          Container image \"nginx:1.29-alpine\" already present on machine and can be accessed by the pod\n82s         Normal    Created             pod/web-86cc98785b-mqxdd          Container created\n82s         Normal    Started             pod/web-86cc98785b-mqxdd          Container started\n82s         Warning   Unhealthy           pod/web-86cc98785b-mqxdd          Readiness probe failed: Get \"http://10.244.0.137:80/healthz\": dial tcp 10.244.0.137:80: connect: connection refused\n82s         Normal    Pulled              pod/api-7d87b9fcf5-5kw75          Container image \"python:3.13-alpine\" already present on machine and can be accessed by the pod\n82s         Warning   Unhealthy           pod/db-5c45bf6fd6-pv76f           Readiness probe failed: /var/run/postgresql:5432 - no response\n82s         Normal    Pulled              pod/web-86cc98785b-rl7gl          Container image \"nginx:1.29-alpine\" already present on machine and can be accessed by the pod\n82s         Normal    Created             pod/web-86cc98785b-rl7gl          Container created\n82s         Normal    Started             pod/web-86cc98785b-rl7gl          Container started\n82s         Warning   Unhealthy           pod/web-86cc98785b-rl7gl          Readiness probe failed: Get \"http://10.244.0.136:80/healthz\": dial tcp 10.244.0.136:80: connect: connection refused\n82s         Normal    Created             pod/api-7d87b9fcf5-5kw75          Container created\n82s         Normal    Created             pod/api-7d87b9fcf5-mxvfv          Container created\n82s         Normal    Pulled              pod/api-7d87b9fcf5-mxvfv          Container image \"python:3.13-alpine\" a","more":1},{"t":10.4,"kind":"say","text":"The timeline is clear: `synthetic` saw 200s until **14:31:01Z**, then 502s from **14:31:03Z**, turning to connection failures (000) by ~14:31:19Z. Both `web` pods fail readiness with **502 on `/healthz`** — nginx itself answers but gets a bad gateway. Let me look at web logs, its nginx config, and rollout history."},{"t":10.5,"kind":"run","cmd":"kubectl -n shop get configmap && kubectl -n shop get configmap -o yaml | head -100","out":"NAME               DATA   AGE\napi-code           2      88s\napi-config         2      88s\nkube-root-ca.crt   1      88s\nweb-nginx          1      88s\napiVersion: v1\nitems:\n- apiVersion: v1\n  data:\n    api.py: |\n      import os, socket, sys, json, time\n      from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer\n      host = os.environ.get(\"DB_HOST\")\n      port = int(os.environ.get(\"DB_PORT\", \"5432\"))\n      if not host:\n          print(\"FATAL: DB_HOST is not set; check ConfigMap api-config\", flush=True)\n          sys.exit(1)\n      def db_ok():\n          try:\n              with socket.create_connection((host, port), timeout=1.0):\n                  return True\n          except OSError as e:\n              print(f\"ERROR db connect {host}:{port}: {e}\", flush=True)\n              return False\n      class H(BaseHTTPRequestHandler):\n          def log_message(self, *a): pass\n          def send(self, code, body):\n              b = json.dumps(body).encode()\n              self.send_response(code); self.send_header(\"Content-Type\", \"application/json\")\n              self.send_header(\"Content-Length\", str(len(b))); self.end_headers(); self.wfile.write(b)\n          def do_GET(self):\n              if self.path == \"/healthz\":\n                  return self.send(200, {\"ok\": True})\n              if self.path.startswith(\"/orders\"):\n                  if db_ok():\n                      return self.send(200, {\"orders\": [{\"id\": 1, \"total\": 42}]})\n                  return self.send(503, {\"error\": \"database unavailable\"})\n              if self.path == \"/jobs\":\n                  return self.send(200, {\"jobs\": [{\"id\": int(time.time())}]})\n              self.send(404, {\"error\": \"not found\"})","more":65},{"t":10.6,"kind":"run","cmd":"kubectl -n shop logs web-86cc98785b-mqxdd --tail=20; echo ---; kubectl -n shop rollout history deploy/web 2>&1; kubectl -n shop rollout history deploy/api 2>&1 | tail -5","out":"10.244.0.1 - - [03/Nov/2026:14:31:26 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n2026/11/03 14:31:26 [error] 28#28: *39 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n2026/11/03 14:31:31 [error] 28#28: *41 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n10.244.0.1 - - [03/Nov/2026:14:31:31 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n2026/11/03 14:31:36 [error] 28#28: *43 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n10.244.0.1 - - [03/Nov/2026:14:31:36 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n10.244.0.1 - - [03/Nov/2026:14:31:41 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n2026/11/03 14:31:41 [error] 28#28: *45 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n10.244.0.1 - - [03/Nov/2026:14:31:46 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n2026/11/03 14:31:46 [error] 28#28: *47 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n10.244.0.1 - - [03/Nov/2026:14:31:51 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n2026/11/03 14:31:51 [error] 31#31: *49 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n2026/11/03 14:31:56 [error] 31#31: *51 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n10.244.0.1 - - [03/Nov/2026:14:31:56 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n2026/11/03 14:32:01 [error] 31#31: *53 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n10.244.0.1 - - [03/Nov/2026:14:32:01 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n2026/11/03 14:32:06 [error] 31#31: *55 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n10.244.0.1 - - [03/Nov/2026:14:32:06 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n2026/11/03 14:32:11 [error] 31#31: *57 connect() failed (111: Connection refused) while connecting to upstream, client: 10.244.0.1, server: , request: \"GET /healthz HTTP/1.1\", upstream: \"http://10.96.179.198:8080/healthz\", host: \"10.244.0.137:80\"\n10.244.0.1 - - [03/Nov/2026:14:32:11 +0000] \"GET /healthz HTTP/1.1\" 502 157 \"-\" \"kube-probe/1.37\" \"-\"\n---\ndeployment.apps/web \nREVISION  CHANGE-CAUSE\n1         <none>\n\ndeployment.apps/api \nREVISION  CHANGE-CAUSE\n1         <none>","more":0},{"t":19.2,"kind":"say","text":"Web's nginx is proxying to `http://api:8080` and getting **connection refused** — but the kubelet probe reaches `api` pods fine on :8080. Notably, `endpoints/api` points to pods on **:8081** while the Service exposes :8080. That smells like a Service port/targetPort mismatch. Let me inspect the Service and Deployment specs, and probe a pod directly."},{"t":19.3,"kind":"run","cmd":"kubectl -n shop get svc api -o yaml","out":"apiVersion: v1\nkind: Service\nmetadata:\n  annotations:\n    kubectl.kubernetes.io/last-applied-configuration: |\n      {\"apiVersion\":\"v1\",\"kind\":\"Service\",\"metadata\":{\"annotations\":{},\"name\":\"api\",\"namespace\":\"shop\"},\"spec\":{\"ports\":[{\"port\":8080}],\"selector\":{\"app\":\"api\"}}}\n  creationTimestamp: \"2026-11-03T14:30:45Z\"\n  name: api\n  namespace: shop\n  resourceVersion: \"113228\"\n  uid: 810da219-0055-4419-9259-fec78d90af31\nspec:\n  clusterIP: 10.96.179.198\n  clusterIPs:\n  - 10.96.179.198\n  internalTrafficPolicy: Cluster\n  ipFamilies:\n  - IPv4\n  ipFamilyPolicy: SingleStack\n  ports:\n  - port: 8080\n    protocol: TCP\n    targetPort: 8081\n  selector:\n    app: api\n  sessionAffinity: None\n  type: ClusterIP\nstatus:\n  loadBalancer: {}","more":0},{"t":19.3,"kind":"run","cmd":"kubectl -n shop get deploy api -o yaml | grep -vE 'last-applied|kubectl-client-side|creationTimestamp:|\"apiVersion\"|f:|^\\s*$' | head -60","out":"apiVersion: apps/v1\nkind: Deployment\nmetadata:\n  annotations:\n    deployment.kubernetes.io/revision: \"1\"\n  generation: 1\n  labels:\n    app: api\n  name: api\n  namespace: shop\n  resourceVersion: \"113190\"\n  uid: cb32d3a6-fb56-4a65-8a94-4fbf91494943\nspec:\n  progressDeadlineSeconds: 600\n  replicas: 2\n  revisionHistoryLimit: 10\n  selector:\n    matchLabels:\n      app: api\n  strategy:\n    rollingUpdate:\n      maxSurge: 25%\n      maxUnavailable: 25%\n    type: RollingUpdate\n  template:\n    metadata:\n      labels:\n        app: api\n    spec:\n      containers:\n      - command:\n        - python\n        - -u\n        - /app/api.py\n        envFrom:\n            name: api-config\n        image: python:3.13-alpine\n        imagePullPolicy: IfNotPresent\n        name: api\n        ports:","more":20},{"t":27.8,"kind":"say","text":"Root cause candidate confirmed:\n\n- **Service `shop/api`**: `port: 8080` → **`targetPort: 8081`**\n- **Deployment `api`**: container listens on **8080** (`containerPort: 8080`, probe on 8080, `api.py` serves on 8080)\n- The Service's `last-applied-configuration` shows it was originally applied with just `{\"port\":8080}` (which defaults targetPort to 8080) — `targetPort: 8081` was added out-of-band afterwards.\n\nSo traffic to `api:8080` is forwarded to pod port 8081 where nothing listens → connection refused → nginx 502 → readiness fails → `endpoints/web` empty → 100% errors. Rollout history shows only revision 1 for both deployments, so this is not a bad rollout. Let me verify the port situation directly, and check the managedFields for evidence of who changed it."},{"t":27.9,"kind":"run","cmd":"kubectl -n shop get svc api -o jsonpath='{range .metadata.managedFields[*]}{.manager}{\" op=\"}{.operation}{\" time=\"}{.time}{\"\\n\"}{end}'","out":"kubectl-client-side-apply op=Update time=2026-11-03T14:30:45Z\nkubectl-patch op=Update time=2026-11-03T14:31:02Z","more":0},{"t":27.9,"kind":"run","cmd":"kubectl -n shop exec web-86cc98785b-mqxdd -- sh -c 'wget -qO- -T2 http://10.244.0.133:8080/healthz && echo POD8080_OK; wget -qO- -T2 http://10.244.0.133:8081/healthz || echo POD8081_REFUSED' 2>&1","out":"{\"ok\": true}POD8080_OK\nPOD8081_REFUSED\nwget: can't connect to remote host (10.244.0.133): Connection refused","more":0},{"t":31.4,"kind":"say","text":"Everything is confirmed:\n\n- `api` pod answers `/healthz` on **:8080**; **:8081 refuses connections**\n- `managedFields`: created by `kubectl-client-side-apply` at 14:30:45 (no explicit targetPort → defaults to 8080), then **`kubectl-patch` at 14:31:02** set `targetPort: 8081` — exactly when `synthetic` started seeing 502s (14:31:03Z)\n\nThe smallest fix, well within my authority: restore `targetPort: 8080` on Service `shop/api`."},{"t":39.5,"kind":"run","cmd":"kubectl -n shop patch svc api --type=json -p='[{\"op\":\"replace\",\"path\":\"/spec/ports/0/targetPort\",\"value\":8080}]' && sleep 8 && kubectl -n shop get endpoints api,web && kubectl -n shop get pods -l app=web","out":"service/api patched\nWarning: v1 Endpoints is deprecated in v1.33+; use discovery.k8s.io/v1 EndpointSlice\nError from server (NotFound): endpoints \"api,web\" not found","more":0},{"t":40.8,"kind":"say","text":"Typo in my verification command (passed `api,web` as a single name). Re-checking properly:"},{"t":41.0,"kind":"run","cmd":"kubectl -n shop get endpoints api web; kubectl -n shop get pods -l app=web","out":"Warning: v1 Endpoints is deprecated in v1.33+; use discovery.k8s.io/v1 EndpointSlice\nNAME   ENDPOINTS                             AGE\napi    10.244.0.133:8080,10.244.0.134:8080   118s\nweb    10.244.0.136:80,10.244.0.137:80       118s\nNAME                   READY   STATUS    RESTARTS   AGE\nweb-86cc98785b-mqxdd   1/1     Running   0          118s\nweb-86cc98785b-rl7gl   1/1     Running   0          118s","more":0},{"t":43.6,"kind":"say","text":"Service fixed, both `web` pods now 1/1 Ready and `endpoints/web` is populated. Final verification: end-to-end health via `synthetic` and a check of `api`/`db` logs per the runbook."},{"t":43.8,"kind":"run","cmd":"kubectl -n shop exec web-86cc98785b-mqxdd -- wget -qO- -T2 http://web/orders; echo; kubectl -n shop logs deploy/api --tail=5; kubectl -n shop logs deploy/db --tail=3","out":"{\"orders\": [{\"id\": 1, \"total\": 42}]}\nFound 2 pods, using pod/api-7d87b9fcf5-5kw75\napi listening on 8080, db=db:5432\n2026-11-03 14:30:46.753 UTC [1] LOG:  listening on Unix socket \"/var/run/postgresql/.s.PGSQL.5432\"\n2026-11-03 14:30:46.754 UTC [74] LOG:  database system was shut down at 2026-11-03 14:30:46 UTC\n2026-11-03 14:30:46.756 UTC [1] LOG:  database system is ready to accept connections","more":0},{"t":48.7,"kind":"run","cmd":"sleep 5; kubectl -n shop logs deploy/synthetic --tail=10","out":"2026-11-03T14:32:31Z GET /orders 000\n2026-11-03T14:32:33Z GET /orders 000\n2026-11-03T14:32:35Z GET /orders 000\n2026-11-03T14:32:37Z GET /orders 200\n2026-11-03T14:32:39Z GET /orders 200\n2026-11-03T14:32:41Z GET /orders 200\n2026-11-03T14:32:43Z GET /orders 200\n2026-11-03T14:32:45Z GET /orders 200\n2026-11-03T14:32:47Z GET /orders 200\n2026-11-03T14:32:49Z GET /orders 200","more":0}],"report":"Service is fully restored — `synthetic` shows 200s continuously since 14:32:37Z, and an end-to-end `GET /orders` through `web → api → db` returns orders successfully. No other alerts are implicated (`worker`, `db`, `events-writer` unaffected; no crash loops).\n\n---\n\n## Investigation summary\n\n1. **Synthetic logs** — 200s until 14:31:01Z, 502s from 14:31:03Z, connection failures (000) from ~14:31:19Z. Failure onset: **14:31:03Z**.\n2. **Rollouts** — `deploy/web` and `deploy/api` both at revision 1; no rollout matched the start time, so no undo.\n3. **Pods/endpoints** — both `web` pods `Running 0/1` (readiness `/healthz` → 502), `endpoints/web` empty → nothing served `/orders`. `web` nginx logs: `connect() failed (111: Connection refused) ... upstream: \"http://10.96.179.198:8080/healthz\"` (the `api` ClusterIP).\n4. **Root cause found** — `svc/api` had `port: 8080 → targetPort: 8081`, but `api` containers listen on 8080 (`containerPort: 8080`, probe on 8080; verified in-pod: `:8080` serves `/healthz`, `:8081` refused). Its `last-applied-configuration` had no `targetPort` (correct default), and `managedFields` shows a `kubectl-patch` updated the Service at **14:31:02Z** — one second before the 502s began.\n5. **Fix** — patched `targetPort` back to 8080; endpoints repointed to `:8080`, web pods went 1/1, `endpoints/web` populated, synthetic 200s resumed.\n\nIMPACT: All `GET /orders` traffic to `shop/web` failed with 5xx/timeouts (100%) from 14:31:03Z to 14:32:37Z (~95 s); `web` was fully unready (0/2, empty endpoints) during the latter half of that window. `api` and `db` themselves stayed healthy.\n\nROOT CAUSE: Service `shop/api` (namespace `shop`), field `spec.ports[0].targetPort` set to `8081` by an out-of-band `kubectl patch` at 14:31:02Z, while the `api` containers listen on `8080` — traffic to the Service hit a closed port, causing nginx 502s, failed readiness, and removal of `web` from endpoints.\n\nACTIONS TAKEN:\n1. Checked `synthetic` logs (failure onset 14:31:03Z) and `rollout history` for `web`/`api` (no relevant rollout; rule 2 N/A).\n2. Described `web` pods/events and read `web` logs → upstream `connect: connection refused` to `api` ClusterIP despite `api` pods being Ready on 8080.\n3. Compared `svc/api` (`targetPort: 8081`) with `deploy/api` (listens/probes on 8080) and verified in-pod that :8080 serves and :8081 refuses; `managedFields` pinned the regression to the 14:31:02Z patch.\n4. `kubectl -n shop patch svc api --type=json -p='[{\"op\":\"replace\",\"path\":\"/spec/ports/0/targetPort\",\"value\":8080}]'` — the only change made.\n5. Verified: `endpoints/api` → `:8080`, both `web` pods 1/1 Ready, `endpoints/web` populated, in-cluster `GET http://web/orders` returns 200 with orders JSON, `synthetic` 200s from 14:32:37Z.\n\nSTATUS: resolved — all `synthetic` probes returning 200 since 14:32:37Z; `web` 2/2 Ready with live endpoints; end-to-end `/orders` request succeeds through `web → api → db`.\n\nESCALATION: none — the fix was a single-field correction inside the `shop` namespace, no restarts, no data loss, and it restored service immediately. The identity of whoever ran the out-of-band patch at 14:31:02Z should be identified for follow-up only.\n\nFOLLOW-UP: Restrict ad-hoc `kubectl patch` on production Services (GitOps-only change path with drift detection), so a manual `targetPort` edit can't silently diverge from the container port declared in the Deployment."}