Docker Registry Exporter

Exports Docker Registry metrics such as repository and tag counts for Prometheus to scrape. Runs separately from your Docker registry and Prometheus server.

Build and run application

Execute the following commands to build and run the Go application in your local environment:

1. git clone https://github.com/pauljwil/docker-registry-exporter
2. cd docker-registry-exporter
3. go build -o docker-registry-exporter
4. ./docker-registry-exporter

Configuration parameters

Configure your Docker Registry Exporter using either CLI flags, environment variables, or a configuration file.

CLI flag	Env var	Config key	Description	Default
--config	N/A	N/A	Configuration file	docker-registry-exporter.yaml
--listen-address	LISTEN_ADDRESS	listen_address	Address to listen on for registry metrics	127.0.0.1:9055
--metrics-path	METRICS_PATH	metrics_path	Path on which to expose metrics to Prometheus	/metrics
--registry-address	REGISTRY_ADDRESS	registry_address	Docker registry address	127.0.0.1:5000

Example configuration file:

listen_address: '127.0.0.1:9055'
metrics_path: '/metrics'
registry_address: '127.0.0.1:5000'

Metrics

The Docker Registry Exporter exposes the following metrics:

Name	Description	Metric type	Labels
repositories	Number of repositories	Gauge	None
tags	Number of tags	Gauge	Name
tags_per_repository	Number of tags per repository	Gauge	repository
scrape_latency	Duration of metrics collection	Gauge	None
scrape_errors	Number of errors while collecting metrics	Gauge	None

For more information on gauge values, refer to Metrics Types in the Prometheus documentation.