Prometheus Source

When you set kind: prometheus on a source, pgwatch scrapes an HTTP endpoint that exposes data in the Prometheus text exposition format and forwards every metric family to the configured sink. This page documents the connection-string format and the presets that ship out of the box. For the recipe to wire pgwatch to Patroni or postgres_exporter, see How-to: Monitor a Prometheus exporter.

Connection string

The conn_str field is a plain HTTP or HTTPS URL. Optional query parameters control TLS validation and are stripped before the request is sent to the exporter.

Query parameter	Description
`tlsskipverify=true`	Disable TLS certificate verification (use with caution).
`tlsrootcert=<path>`	Absolute path to a PEM-encoded CA certificate file used to verify the server certificate.

Basic Auth credentials are embedded in the URL in the standard user:password@host form.

Examples

# Plain HTTP - no auth
conn_str: "http://patroni-node1:8008/metrics"

# HTTPS with a custom CA certificate
conn_str: "https://patroni-node1:8008/metrics?tlsrootcert=/etc/ssl/certs/my-ca.pem"

# HTTPS with Basic Auth and TLS certificate verification disabled
conn_str: "https://user:secret@patroni-node1:8008/metrics?tlsskipverify=true"

Presets

`patroni`

Covers the key metric families emitted by Patroni's GET /metrics endpoint (default port 8008):

Metric family	What it measures	Interval
`patroni_postgres_running`	1 if Postgres is running	30 s
`patroni_primary`	1 if this node is the primary	30 s
`patroni_replica`	1 if this node is a replica	30 s
`patroni_standby_leader`	1 if this node is standby leader	30 s
`patroni_cluster_unlocked`	1 if the cluster has no leader lock	30 s
`patroni_xlog_location`	WAL location on primary	30 s
`patroni_xlog_received_location`	received WAL on replica	30 s
`patroni_xlog_replayed_location`	replayed WAL on replica	30 s
`patroni_dcs_last_seen`	seconds since DCS last contacted	30 s
`patroni_pending_restart`	1 if node needs a restart	60 s
`patroni_is_paused`	1 if auto-failover is disabled	60 s
`patroni_postgres_timeline`	Postgres timeline	60 s

`postgres-exporter-basic`

Covers the most important metric families emitted by postgres_exporter:

Metric family	Interval
`pg_stat_activity_count`	30 s
`pg_stat_bgwriter_checkpoints_timed`	60 s
`pg_stat_replication_pg_wal_lsn_diff`	30 s

Custom metrics

Specify individual metric families and their intervals with custom_metrics:

- name: patroni-prod-node1
  kind: prometheus
  conn_str: "http://patroni-node1:8008/metrics"
  custom_metrics:
    patroni_primary: 30
    patroni_cluster_unlocked: 30
    patroni_dcs_last_seen: 30
  is_enabled: true

Custom tags

Use custom_tags to attach arbitrary key-value pairs to every stored data point. This is useful when multiple nodes feed the same sink and you need to distinguish them:

- name: patroni-prod-node1
  kind: prometheus
  conn_str: "http://patroni-node1:8008/metrics"
  preset_metrics: patroni
  custom_tags:
    cluster: prod
    node: node1
  is_enabled: true