odonate / postgres-exporter

Prometheus exporter for PostgreSQL server-side metrics.

PostgreSQL Exporter

Prometheus exporter for PostgreSQL server-side metrics.

Tested PostgreSQL Versions: 11

This library is intended as an alternative to the prometheus-community's postgres_exporter, which still uses lib/pq; a library that is in maintenance mode.

Instead, we leverage pgx, which aims to be low-level, fast, and performant, while also enabling PostgreSQL-specific features that the standard database/sql package does not allow for (and also it is actively maintained).

We also offer support for multi-target scraping (see below).

Options

Long Flag	ENV Flag	Default	Description
--postgres_host	$POSTGRES_HOST	localhost	PostgreSQL Host
--postgres_port	$POSTGRES_PORT	5432	PostgreSQL Port
--postgres_user	$POSTGRES_USER	postgres	PostgreSQL User
--postgres_database	$POSTGRES_DATABASE	postgres	PostgreSQL Database
--postgres_password	$POSTGRES_PASSWORD	postgres	PostgreSQL Password
--auth_mechanism	$AUTH_MECHANISM	password	The mechanism to use when authenticating with the DB
--application_name	$APP_NAME	postgres-exporter	The name of the application.
--default_isolation_level	$DEFAULT_ISOLATION_LEVEL	REPEATABLE_READ	The default isolation level for DB transactions

Features

Default Collectors for the following tables:

1. pg_locks
2. pg_stat_activity
3. pg_stat_statements
4. pg_stat_user_indexes
5. pg_stat_user_tables
6. pg_statio_user_indexes
7. pg_statio_user_indexes

Custom Collectors can be added like so, provided they satisfy our Collector interface:

type Collector interface {
	prometheus.Collector
	Scrape(ch chan<- prometheus.Metric) error
}

...

exporter := exporter.MustNew(context.Background(), exporterOpts).
		     WithCustomCollectors(collectors...)

Example Usage

Single Target

Go Binary

import (
	"github.com/odonate/postgres-exporter/exporter"
	"github.com/odonate/postgres-exporter/exporter/db"
)

var opts struct {
  DB db.Opts `group:"Postgres"`
}

func main() {
  flags.MustParse(&opts)
  exporterOpts := exporter.Opts{DBOpts: []db.Opts{opts.DB}}
  exporter := exporter.MustNew(context.Background(), exporterOpts)
  exporter.Register()
  ...

Kubernetes Deployment

---
apiVersion: apps/v1
kind: Deployment
metadata: 
  ...
spec:
  ...
    spec:
      containers:
      - name: main
        image: <Go-Binary-Docker-Image>
        args:
          - --application_name=postgres-exporter
        resources:
          requests:
            memory: 20Mi
            cpu: 5m
          limits:
            memory: 10Mi
            cpu: 10m
        ports:
        - containerPort: 13434
          name: prometheus

        envFrom:
          - secretRef:
              name: your-db-secret

Multi-Target

Go Binary

import (
	"github.com/odonate/postgres-exporter/exporter"
	"github.com/odonate/postgres-exporter/exporter/db"
)

var opts struct {
  FirstDB db.Opts{} `namespace:"first" env-namespace:"FIRST"`
  SecondDB db.Opts{} `namespace:"second" env-namespace:"SECOND"`
}

func main() {
  flags.MustParse(&opts)
  exporterOpts := exporter.Opts{
    DBOpts: []db.Opts{
      opts.FirstDB, 
      opts.SecondDB,
    },
  }
  exporter := exporter.MustNew(context.Background(), exporterOpts)
  exporter.Register()
  ...

Kubernetes Deployment

---
apiVersion: apps/v1
kind: Deployment
metadata: 
  ...
spec:
  ...
    spec:
      containers:
      - name: main
        image: <Go-Binary-Docker-Image>
        args:
          - --first.application_name=postgres-exporter
          - --second.application_name=postgres-exporter
        resources:
          requests:
            memory: 20Mi
            cpu: 5m
          limits:
            memory: 10Mi
            cpu: 10m
        ports:
        - containerPort: 13434
          name: prometheus
        envFrom:
          - secretRef:
              name: your-first-db-secret
            prefix: FIRST_
          - secretRef:
              name: your-second-db-secret
            prefix: SECOND_