Deployment

Production deployment — connection & credentials, systemd / Docker / Kubernetes, auto-discovery and alerting

Use this page to deploy pg_exporter in production. It describes process arguments, environment variables, monitoring users, credentials, and deployment with systemd, Docker, or Kubernetes. It also describes pgBouncer monitoring, auto-discovery, Prometheus scrapes, and alerts.

The exporter reads process configuration from two sources. Command-line arguments take precedence:

Command-line arguments (--url, --config, …)
Environment variables (every flag has a corresponding PG_EXPORTER_* variable)

YAML collector definitions control metric collection. The default file is /etc/pg_exporter.yml. You can also use a configuration directory. See the Configuration reference.

Command-Line Arguments

pg_exporter \
  --url="postgres://monitor:S3cret@localhost:5432/postgres" \
  --config="/etc/pg_exporter.yml" \
  --web.listen-address=":9630" \
  --auto-discovery \
  --log.level="info"

The full flag list from pg_exporter --help:

Flags:
  -h, --[no-]help                Show context-sensitive help (also try --help-long and --help-man).
  -u, --url=URL                  postgres target url
  -c, --config=CONFIG            path to config dir or file
      --web.listen-address=:9630 ...
                                 Addresses on which to expose metrics and web interface. Repeatable for multiple addresses. Examples: `:9100` or `[::1]:9100` for http, `vsock://:9100` for vsock
      --web.config.file=""       Path to configuration file that can enable TLS or authentication. See: https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md
  -l, --label=""                 constant labels: comma separated list of label=value pair ($PG_EXPORTER_LABEL)
  -t, --tag=""                   tags, comma separated list of server tag ($PG_EXPORTER_TAG)
  -C, --[no-]disable-cache       force not using cache ($PG_EXPORTER_DISABLE_CACHE)
  -m, --[no-]disable-intro       disable internal/exporter self-monitoring metrics (only expose query metrics) ($PG_EXPORTER_DISABLE_INTRO)
  -a, --[no-]auto-discovery      automatically scrape all databases on the target server ($PG_EXPORTER_AUTO_DISCOVERY)
  -x, --exclude-database="template0,template1,postgres"
                                 excluded databases when auto-discovery is enabled ($PG_EXPORTER_EXCLUDE_DATABASE)
  -i, --include-database=""      included databases when auto-discovery is enabled ($PG_EXPORTER_INCLUDE_DATABASE)
  -n, --namespace=""             prefix of built-in metrics, (pg|pgbouncer) by default ($PG_EXPORTER_NAMESPACE)
  -f, --[no-]fail-fast           fail fast instead of waiting during start-up ($PG_EXPORTER_FAIL_FAST)
  -T, --connect-timeout=100      connect timeout in ms, 100 by default ($PG_EXPORTER_CONNECT_TIMEOUT)
  -P, --web.telemetry-path="/metrics"
                                 URL path under which to expose metrics ($PG_EXPORTER_TELEMETRY_PATH)
  -D, --[no-]dry-run             dry run and print raw configs
  -E, --[no-]explain             explain server planned queries
      --log.level="info"         log level: debug|info|warn|error
      --log.format="logfmt"      log format: logfmt|json
      --[no-]version             Show application version.

These behaviors affect deployment:

Startup policy: startup is non-blocking by default. If the database is unreachable, HTTP endpoints still start. A background probe retries until recovery. To fail when the database is unreachable, set --fail-fast. For example, use this option when systemd or an orchestrator controls restarts.
Telemetry path validation: from v1.4.0, startup validates --web.telemetry-path. Empty paths, conflicts with built-in endpoints, and non-canonical paths such as //metrics fail immediately with an error. Non-canonical paths cannot match requests.

Connection URL Sources

The exporter uses the first non-empty connection string from this list:

--url / -u command-line argument
PG_EXPORTER_URL environment variable
PGURL environment variable
Content of the file pointed to by PG_EXPORTER_URL_FILE (fits container Secret mounts)
Default postgresql:///?sslmode=disable (local-first, fits same-host deployment)

If the URL omits sslmode, the exporter appends sslmode=disable. At startup, it also clears libpq service-file environment variables, such as PGSERVICE / PGSERVICEFILE, and logs this action. Service files can override an explicit connection target. Clearing these variables ensures that the exporter connects to the URL shown in the log.

Monitoring User and Credentials

Create the Monitoring User

CREATE ROLE monitor WITH LOGIN PASSWORD 'S3cret' CONNECTION LIMIT 5;
GRANT pg_monitor TO monitor;   -- built-in monitoring role (PostgreSQL 10+), covers all default collectors

Keep CONNECTION LIMIT to prevent connection exhaustion if the configuration is incorrect. The exporter normally uses one to a few connections. With auto-discovery, it uses one connection per database.

Manage Passwords with .pgpass

Remove the password from the URL. Use libpq’s .pgpass file to supply it:

# Create as the OS user that runs the exporter
echo "localhost:5432:*:monitor:S3cret" > ~/.pgpass
chmod 600 ~/.pgpass

# URL without password
PG_EXPORTER_URL='postgres://monitor@localhost:5432/postgres'

RPM/DEB package installs

Packaged services run as the prometheus system user. From v1.4.0, its HOME is /var/lib/prometheus. Libpq looks for ~/.pgpass there. The package does not create this directory. Before you use .pgpass, run: install -d -o prometheus -g prometheus /var/lib/prometheus

TLS for the Database Connection

PG_EXPORTER_URL='postgres://monitor:[email protected]:5432/postgres?sslmode=verify-full&sslrootcert=/etc/pki/ca.crt'

Protecting the HTTP Port

The HTTP port provides /metrics and the management endpoints /reload, /explain, and /stat. Anyone with access to the port can read configuration and runtime state, or start a reload. On a shared network, enable TLS / Basic Auth with --web.config.file (exporter-toolkit web configuration). You can also restrict access through a firewall or reverse proxy.

Systemd Deployment (RPM/DEB packages)

RPM/DEB packages include a service unit and an environment file. After installation, edit the environment file and start the service:

# /usr/lib/systemd/system/pg_exporter.service
[Unit]
Description=Prometheus exporter for PostgreSQL/Pgbouncer server metrics
Documentation=https://pigsty.io/docs/pg_exporter
After=network.target

[Service]
EnvironmentFile=-/etc/default/pg_exporter
User=prometheus
ExecStart=/usr/bin/pg_exporter $PG_EXPORTER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target

Environment file /etc/default/pg_exporter (package defaults):

PG_EXPORTER_URL='postgres://:5432/postgres?sslmode=disable'
PG_EXPORTER_CONFIG=/etc/pg_exporter.yml
PG_EXPORTER_LABEL=""
PG_EXPORTER_TAG=""
PG_EXPORTER_DISABLE_CACHE=false
PG_EXPORTER_AUTO_DISCOVERY=true
PG_EXPORTER_EXCLUDE_DATABASE="template0,template1,postgres"
PG_EXPORTER_INCLUDE_DATABASE=""
PG_EXPORTER_NAMESPACE="pg"
PG_EXPORTER_FAIL_FAST=false
PG_EXPORTER_CONNECT_TIMEOUT=100
PG_EXPORTER_TELEMETRY_PATH="/metrics"
PG_EXPORTER_OPTS='--log.level=info'

Each command-line flag has an environment variable. Add the variables you need, such as PG_EXPORTER_DISABLE_INTRO. The file uses the noreplace package option. Upgrades do not overwrite your changes.

Common operations:

sudo systemctl enable --now pg_exporter    # start and enable at boot
sudo systemctl status pg_exporter          # check status
journalctl -u pg_exporter -f               # follow logs
curl -X POST localhost:9630/reload         # hot-reload collector config (no restart)

Docker Deployment

docker run -d \
  --name pg_exporter \
  --restart unless-stopped \
  -p 9630:9630 \
  -e PG_EXPORTER_URL="postgres://monitor:S3cret@host:5432/postgres" \
  pgsty/pg_exporter:latest

Docker Compose:

services:
  pg_exporter:
    image: pgsty/pg_exporter:latest
    container_name: pg_exporter
    restart: unless-stopped
    ports:
      - "9630:9630"
    environment:
      - PG_EXPORTER_URL=postgres://monitor:S3cret@postgres:5432/postgres
    volumes:
      - ./pg_exporter.yml:/etc/pg_exporter.yml:ro   # optional: custom collector config
    depends_on:
      - postgres

Note

The official image is built from scratch. It contains no system CA certificates. To connect to remote PostgreSQL with sslmode=verify-ca / verify-full, mount a CA certificate and set sslrootcert to its path. Without the certificate, TLS verification cannot complete.

Kubernetes Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: pg-exporter
  labels: { app: pg-exporter }
spec:
  replicas: 1
  selector:
    matchLabels: { app: pg-exporter }
  template:
    metadata:
      labels: { app: pg-exporter }
    spec:
      containers:
      - name: pg-exporter
        image: pgsty/pg_exporter:latest
        ports:
        - containerPort: 9630
        env:
        - name: PG_EXPORTER_URL
          valueFrom:
            secretKeyRef:
              name: pg-credentials
              key: connection-url
        livenessProbe:
          httpGet: { path: /liveness, port: 9630 }
          initialDelaySeconds: 30
          periodSeconds: 10
        readinessProbe:
          httpGet: { path: /readiness, port: 9630 }
          initialDelaySeconds: 5
          periodSeconds: 5
        resources:
          requests: { cpu: 100m, memory: 128Mi }
          limits: { cpu: 200m, memory: 256Mi }
---
apiVersion: v1
kind: Service
metadata:
  name: pg-exporter
  labels: { app: pg-exporter }
spec:
  ports:
  - { port: 9630, targetPort: 9630, name: metrics }
  selector: { app: pg-exporter }

To keep the connection string out of environment variables, set PG_EXPORTER_URL_FILE to a Secret-mounted file.

Auto-Discovery

Auto-discovery is enabled by default. It lets one exporter instance monitor every database in the target PostgreSQL instance:

pg_exporter --auto-discovery \
  --exclude-database="template0,template1,postgres" \  # default exclusion list
  --include-database=""                                # set to switch to allowlist mode

Behavior:

Cluster-level collectors (tags: [cluster]) run once on the primary connection
Database-level collectors run on every discovered database, with metrics distinguished by the datname label
Newly created / dropped databases are picked up / removed in subsequent planning cycles

Monitoring pgBouncer

Set the database name in the URL to pgbouncer. This name activates pgBouncer mode:

PG_EXPORTER_URL='postgres://stats_user:S3cret@localhost:6432/pgbouncer' pg_exporter

In pgBouncer mode, the exporter uses the pgbouncer metric prefix. It runs only pgBouncer collectors, such as SHOW STATS / SHOW POOLS. Usually, you run one exporter for PostgreSQL and another for pgBouncer. Give each exporter a different port.

Prometheus Scraping and Alerting

Scrape Configuration

scrape_configs:
  - job_name: 'postgresql'
    scrape_interval: 15s
    static_configs:
      - targets: ['pg-1:9630', 'pg-2:9630', 'pg-3:9630']

Kubernetes service discovery:

scrape_configs:
  - job_name: 'postgresql'
    kubernetes_sd_configs:
      - role: pod
    relabel_configs:
      - source_labels: [__meta_kubernetes_pod_label_app]
        regex: pg-exporter
        action: keep
      - source_labels: [__meta_kubernetes_pod_ip]
        target_label: __address__
        replacement: ${1}:9630

Set the scrape interval equal to or greater than the common collector ttl. Most collectors in the default bundle use 10 seconds. More frequent scrapes return cached results until the TTL expires.

Alert Rules

The following rules use available metrics:

groups:
  - name: pg_exporter
    rules:
      # Exporter process unreachable
      - alert: PgExporterDown
        expr: up{job="postgresql"} == 0
        for: 1m
        labels: { severity: critical }
        annotations:
          summary: "pg_exporter down ({{ $labels.instance }})"

      # Exporter alive but cannot reach the database
      - alert: PostgreSQLDown
        expr: pg_up == 0
        for: 1m
        labels: { severity: critical }
        annotations:
          summary: "PostgreSQL connection failed ({{ $labels.instance }})"

      # Overall scrape duration abnormal (unit: seconds)
      - alert: PgExporterSlowScrape
        expr: pg_exporter_scrape_duration > 10
        for: 5m
        labels: { severity: warning }
        annotations:
          summary: "pg_exporter slow scrape ({{ $labels.instance }})"

      # A specific collector keeps failing (locate by datname/query)
      - alert: PgExporterQueryError
        expr: increase(pg_exporter_query_scrape_error_count[10m]) > 0
        for: 10m
        labels: { severity: warning }
        annotations:
          summary: "Collector {{ $labels.query }} keeps failing on {{ $labels.datname }}"

Role-Based Traffic Routing

Use /primary, /replica, and /read as health probes for HAProxy or similar load balancers. These endpoints support primary/replica routing to separate read and write traffic. For endpoint behavior and a complete HAProxy example, see the API Reference.

Open-source Nginx does not support active HTTP health checks outside the traffic connection. The health_check directive requires NGINX Plus. To route PostgreSQL traffic by role, use HAProxy or a solution such as Patroni + vip-manager.