linearvoid/docs/infrastructure/monitoring/prometheus_curl.md

Prometheus scrape target metric names

Here are ready‑to‑run cURL commands you can use to query each Prometheus scrape target and list the metric names they expose.
The Prometheus HTTP API endpoint http://localhost:9090/api/v1/label/__name__/values returns all metric names currently known for the target’s job/instance.

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1. Chat (http://chat:3000/metrics)

curl -s 'http://localhost:9090/api/v1/label/__name__/values?match[]={job="chat",instance="chat:3000"}' | jq .

2. NGINX exporter (http://nginx-exporter:9113/metrics)

curl -s 'http://localhost:9090/api/v1/label/__name__/values?match[]={job="nginx",instance="nginx-exporter:9113"}' | jq .

3. Node exporter (http://node-exporter:9100/metrics)

curl -s 'http://localhost:9090/api/v1/label/__name__/values?match[]={job="node",instance="node-exporter:9100"}' | jq .

4. Playout (http://playout:8081/metrics)

curl -s 'http://localhost:9090/api/v1/label/__name__/values?match[]={job="playout",instance="playout:8081"}' | jq .

5. Postgres exporter (http://postgres-exporter:9187/metrics)

curl -s 'http://localhost:9090/api/v1/label/__name__/values?match[]={job="postgres",instance="postgres-exporter:9187"}' | jq .

6. Prometheus itself (http://prometheus:9090/metrics)

curl -s 'http://localhost:9090/api/v1/label/__name__/values?match[]={job="prometheus",instance="prometheus:9090"}' | jq .

7. Redis exporter (http://redis-exporter:9121/metrics)

curl -s 'http://localhost:9090/api/v1/label/__name__/values?match[]={job="redis",instance="redis-exporter:9121"}' | jq .

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How it works

• http://localhost:9090 – address of your Prometheus server.
• /api/v1/label/__name__/values – API call that lists all metric names (__name__ label) known to Prometheus.
• match[] – a selector that restricts the result to the specific job and instance you care about.
• -s – silent mode (no progress meter).
• | jq . – pretty‑prints the JSON response (optional but handy).

Running any of these commands will output a JSON array like:

[
  "up",
  "process_cpu_seconds_total",
  "http_requests_total",
  ...
]

which is the full set of metrics currently being scraped from that target. Adjust the Prometheus host/port if it differs from http://localhost:9090.