Sign inSign up
PostgreSQL Exporter

dhi.io/postgres-exporter

PostgreSQL Exporter

CIS
FIPS
STIG
linux/amd64
linux/arm64

A Prometheus exporter for monitoring PostgreSQL server metrics, exposing database statistics, connection info, and query performance.

OverviewGuidesImages

How to use this image

All examples in this guide use the public image. If you've mirrored the repository for your own use (for example, to your Docker Hub namespace), update your commands to reference the mirrored image instead of the public one.

For example:

  • Public image: dhi.io/<repository>:<tag>
  • Mirrored image: <your-namespace>/dhi-<repository>:<tag>

For the examples, you must first use docker login dhi.io to authenticate to the registry to pull the images.

Start a Postgres Exporter instance

Run the following command and replace <tag> with the image variant you want to run.

# First, start a PostgreSQL instance
docker run -d \
  --name postgres-server \
  -e POSTGRES_PASSWORD=mysecretpassword \
  -p 5432:5432 \
  dhi.io/postgres:18

# Then start the postgres-exporter
docker run -d \
  --name postgres-exporter \
  -p 9187:9187 \
  -e DATA_SOURCE_NAME="postgresql://postgres:mysecretpassword@postgres-server:5432/postgres?sslmode=disable" \
  --link postgres-server \
  dhi.io/postgres-exporter:<tag>

# Verify it's working
curl http://localhost:9187/metrics

# Clean up after testing
docker rm -f postgres-server postgres-exporter

Common Postgres Exporter use cases

Custom metrics with queries.yaml

Create a custom queries configuration file:

# Create queries.yaml
cat > queries.yaml << 'EOF'
pg_replication:
  query: "SELECT CASE WHEN NOT pg_is_in_recovery() THEN 0 ELSE GREATEST (0, EXTRACT(EPOCH FROM (now() - pg_last_xact_replay_timestamp()))) END AS lag"
  master: true
  metrics:
    - lag:
        usage: "GAUGE"
        description: "Replication lag behind master in seconds"

pg_postmaster:
  query: "SELECT pg_postmaster_start_time as start_time_seconds from pg_postmaster_start_time()"
  master: true
  metrics:
    - start_time_seconds:
        usage: "GAUGE"
        description: "Time at which postmaster started"
EOF

# Run exporter with custom queries
docker run -d \
  --name postgres-exporter \
  -p 9187:9187 \
  -v $(pwd)/queries.yaml:/queries.yaml:ro \
  -e DATA_SOURCE_NAME="postgresql://postgres:mysecretpassword@postgres-server:5432/postgres?sslmode=disable" \
  -e PG_EXPORTER_EXTEND_QUERY_PATH="/queries.yaml" \
  --link postgres-server \
  dhi.io/postgres-exporter:<tag>

# Clean up after testing
docker rm -f postgres-exporter
rm queries.yaml
TLS/SSL connection

Monitor PostgreSQL with TLS/SSL enabled:

# Start exporter with TLS connection
docker run -d \
  --name postgres-exporter-tls \
  -p 9187:9187 \
  -e DATA_SOURCE_NAME="postgresql://postgres:mysecretpassword@postgres-server:5432/postgres?sslmode=require" \
  --link postgres-server \
  dhi.io/postgres-exporter:<tag>

# For advanced TLS configurations with certificates
docker run -d \
  --name postgres-exporter-tls \
  -p 9187:9187 \
  -v /path/to/certs:/certs:ro \
  -e DATA_SOURCE_NAME="postgresql://postgres:mysecretpassword@postgres-server:5432/postgres?sslmode=verify-full&sslrootcert=/certs/ca.crt&sslcert=/certs/client.crt&sslkey=/certs/client.key" \
  --link postgres-server \
  dhi.io/postgres-exporter:<tag>

# Clean up after testing
docker rm -f postgres-exporter-tls
Docker Compose deployment

Complete monitoring stack with PostgreSQL and PostgreSQL Exporter:

services:
  postgres:
    image: dhi.io/postgres:18
    container_name: postgres-server
    environment:
      POSTGRES_PASSWORD: mysecretpassword
      POSTGRES_DB: mydb
    ports:
      - "5432:5432"
    volumes:
      - postgres-data:/var/lib/postgresql/data
    restart: unless-stopped

  postgres-exporter:
    image: dhi.io/postgres-exporter:<tag>
    container_name: postgres-exporter
    environment:
      DATA_SOURCE_NAME: "postgresql://postgres:mysecretpassword@postgres:5432/postgres?sslmode=disable"
    ports:
      - "9187:9187"
    depends_on:
      - postgres
    restart: unless-stopped

volumes:
  postgres-data:
Integration with Prometheus

Configure Prometheus to scrape PostgreSQL Exporter metrics:

First, create prometheus.yml:

global:
  scrape_interval: 15s
  evaluation_interval: 15s

scrape_configs:
  - job_name: 'postgres'
    static_configs:
      - targets: ['postgres-exporter:9187']

Then create docker-compose.yml:

services:
  postgres:
    image: dhi.io/postgres:18
    container_name: postgres-server
    environment:
      POSTGRES_PASSWORD: mysecretpassword
      POSTGRES_DB: mydb
    volumes:
      - postgres-data:/var/lib/postgresql/data

  postgres-exporter:
    image: dhi.io/postgres-exporter:<tag>
    container_name: postgres-exporter
    environment:
      DATA_SOURCE_NAME: "postgresql://postgres:mysecretpassword@postgres:5432/postgres?sslmode=disable"
    depends_on:
      - postgres

  prometheus:
    image: dhi.io/prometheus:3
    container_name: prometheus
    ports:
      - "9090:9090"
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml:ro
      - prom_data:/var/prometheus
    depends_on:
      - postgres-exporter

volumes:
  postgres-data:
  prom_data:
Kubernetes deployment

Deploy postgres-exporter in Kubernetes to monitor PostgreSQL instances:

apiVersion: v1
kind: ConfigMap
metadata:
  name: postgres-exporter-config
  namespace: monitoring
data:
  DATA_SOURCE_NAME: "postgresql://postgres:password@postgres-service:5432/postgres?sslmode=disable"
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres-exporter
  namespace: monitoring
  labels:
    app: postgres-exporter
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgres-exporter
  template:
    metadata:
      labels:
        app: postgres-exporter
    spec:
      containers:
      - name: postgres-exporter
        image: dhi.io/postgres-exporter:<tag>
        ports:
        - containerPort: 9187
          name: metrics
        env:
        - name: DATA_SOURCE_NAME
          valueFrom:
            configMapKeyRef:
              name: postgres-exporter-config
              key: DATA_SOURCE_NAME
        livenessProbe:
          httpGet:
            path: /
            port: 9187
          initialDelaySeconds: 30
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /
            port: 9187
          initialDelaySeconds: 5
          periodSeconds: 5
        resources:
          limits:
            cpu: 100m
            memory: 128Mi
          requests:
            cpu: 50m
            memory: 64Mi
---
apiVersion: v1
kind: Service
metadata:
  name: postgres-exporter
  namespace: monitoring
  labels:
    app: postgres-exporter
spec:
  type: ClusterIP
  ports:
  - port: 9187
    targetPort: 9187
    name: metrics
  selector:
    app: postgres-exporter
ServiceMonitor for Prometheus Operator
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: postgres-exporter
  namespace: monitoring
  labels:
    app: postgres-exporter
spec:
  selector:
    matchLabels:
      app: postgres-exporter
  endpoints:
  - port: metrics
    interval: 30s
    path: /metrics

Image variants

Docker Hardened Images come in different variants depending on their intended use.

Available image tags for postgres-exporter:

Variant TypeTag ExamplesDescription
Standard (Debian)0.18.1, 0.18, 0Runtime variants for production use
0.18.1-debian13, 0.18-debian13, 0-debian13Explicit Debian base specification
FIPS (Debian)0.18.1-fips, 0.18-fips, 0-fipsFIPS-validated cryptographic modules
0.18.1-debian13-fips, 0.18-debian13-fipsFIPS with explicit Debian base

Tag selection guidance:

  • Use dhi.io/postgres-exporter:0.18.1 for standard production deployments
  • Use dhi.io/postgres-exporter:0.18.1-fips for FIPS-compliant environments
  • Use major version tags (like :0) for automatic minor updates (not recommended for production)

Runtime variants are designed to run your application in production. These images are intended to be used either directly or as the FROM image in the final stage of a multi-stage build. These images typically:

  • Run as the nonroot user
  • Do not include a shell or a package manager
  • Contain only the minimal set of libraries needed to run the app

Build-time variants typically include dev in the variant name and are intended for use in the first stage of a multi-stage Dockerfile. These images typically:

  • Run as the root user
  • Include a shell and package manager
  • Are used to build or compile applications
FIPS variants

FIPS variants include fips in the variant name and tag. For PostgreSQL Exporter DHI, only runtime variants are available. These variants use cryptographic modules that have been validated under FIPS 140, a U.S. government standard for secure cryptographic operations.

Runtime requirements specific to FIPS:

  • FIPS mode restricts cryptographic operations to FIPS-validated algorithms
  • Usage of non-compliant operations (like MD5) will fail
  • Larger image size due to FIPS-validated cryptographic libraries

Steps to verify FIPS:

# Check if FIPS variant is being used
docker inspect dhi.io/postgres-exporter:<tag> | grep fips

# Verify FIPS mode in running container (if applicable)
docker logs <container-name>

Migrate to a Docker Hardened Image

To migrate your application to a Docker Hardened Image, you must update your Dockerfile. At minimum, you must update the base image in your existing Dockerfile to a Docker Hardened Image. This and a few other common changes are listed in the following table of migration notes:

ItemMigration note
Base imageReplace your base images in your Dockerfile with a Docker Hardened Image.
Package managementNon-dev images, intended for runtime, don't contain package managers. Use package managers only in images with a dev tag.
Non-root userBy default, non-dev images, intended for runtime, run as the nonroot user. Ensure that necessary files and directories are accessible to the nonroot user.
Multi-stage buildUtilize images with a dev tag for build stages and non-dev images for runtime. For binary executables, use a static image for runtime.
TLS certificatesDocker Hardened Images contain standard TLS certificates by default. There is no need to install TLS certificates.
PortsNon-dev hardened images run as a nonroot user by default. As a result, applications in these images can't bind to privileged ports (below 1024) when running in Kubernetes or in Docker Engine versions older than 20.10. PostgreSQL Exporter default port 9187 works without issues.
Entry pointDocker Hardened Images may have different entry points than images such as Docker Official Images. Inspect entry points for Docker Hardened Images and update your Dockerfile if necessary.
No shellBy default, non-dev images, intended for runtime, don't contain a shell. Use dev images in build stages to run shell commands and then copy artifacts to the runtime stage.

The following steps outline the general migration process.

  1. Find hardened images for your app.

    A hardened image may have several variants. Inspect the image tags and find the image variant that meets your needs.

  2. Update the base image in your Dockerfile.

    Update the base image in your application's Dockerfile to the hardened image you found in the previous step. For framework images, this is typically going to be an image tagged as dev because it has the tools needed to install packages and dependencies.

  3. For multi-stage Dockerfiles, update the runtime image in your Dockerfile.

    To ensure that your final image is as minimal as possible, you should use a multi-stage build. All stages in your Dockerfile should use a hardened image. While intermediary stages will typically use images tagged as dev, your final runtime stage should use a non-dev image variant.

  4. Install additional packages

    Docker Hardened Images contain minimal packages in order to reduce the potential attack surface. You may need to install additional packages in your Dockerfile. Inspect the image variants to identify which packages are already installed.

    Only images tagged as dev typically have package managers. You should use a multi-stage Dockerfile to install the packages. Install the packages in the build stage that uses a dev image. Then, if needed, copy any necessary artifacts to the runtime stage that uses a non-dev image.

    For Alpine-based images, you can use apk to install packages. For Debian-based images, you can use apt-get to install packages.

Troubleshooting migration

General debugging

The hardened images intended for runtime don't contain a shell nor any tools for debugging. The recommended method for debugging applications built with Docker Hardened Images is to use Docker Debug⁠ to attach to these containers. Docker Debug provides a shell, common debugging tools, and lets you install other tools in an ephemeral, writable layer that only exists during the debugging session.

Permissions

By default image variants intended for runtime, run as the nonroot user. Ensure that necessary files and directories are accessible to the nonroot user. You may need to copy files to different directories or change permissions so your application running as the nonroot user can access them.

Privileged ports

Non-dev hardened images run as a nonroot user by default. As a result, applications in these images can't bind to privileged ports (below 1024) when running in Kubernetes or in Docker Engine versions older than 20.10.

No shell

By default, image variants intended for runtime don't contain a shell. Use dev images in build stages to run shell commands and then copy any necessary artifacts into the runtime stage. In addition, use Docker Debug to debug containers with no shell.

Entry point

Docker Hardened Images may have different entry points than images such as Docker Official Images. Use docker inspect to inspect entry points for Docker Hardened Images and update your Dockerfile if necessary.

On this page

How to use this imageStart a Postgres Exporter instanceCommon Postgres Exporter use casesCustom metrics with queries.yamlTLS/SSL connectionDocker Compose deploymentIntegration with PrometheusKubernetes deploymentServiceMonitor for Prometheus OperatorImage variantsFIPS variantsMigrate to a Docker Hardened ImageTroubleshooting migrationGeneral debuggingPermissionsPrivileged portsNo shellEntry point