Final test: Observability: metrics, alerts, logs

Read the output

What is most likely wrong with the labapp job's target?

$ curl -s localhost:9090/api/v1/targets | jq '.data.activeTargets[] | select(.labels.job=="labapp") | {health, lastError}'
{
  "health": "down",
  "lastError": "Get \"http://127.0.0.1:8000/metrics\": dial tcp 127.0.0.1:8000: connect: connection refused"
}

• A Prometheus has not finished reading the config — the labapp job is not loaded yet.
• B The app answered, but the metric format is broken.
• C Nobody listens on 127.0.0.1:8000 — the app is not running or listens on another port.