homecentr / docker-dns-exporter

HomeCenter - DNS exporter

BIND9 DNS Prometheus exporter.

Usage

version: "3.7"
services:
  dns_exporter:
    build: .
    restart: unless-stopped
    ports:
      - "9119:9119/tcp"

Configuration

The exporter needs to know on which URL to look for the BIND9 statistics. The url should be passed by the command line argument -bind.stats-url.

The command line arguments also include an option to change the port on which the metrics are exposed. Do not do this as it breaks the health check. Instead map the port 9119 to any external port you like using Docker configuration.

Configuring BIND to expose statistics

BIND9 does not expose the statistics by default. You need to include the statistics-channels section in your named.conf file.

Environment variables

Name	Default value	Description
PUID	7077	UID of the user dns-exporter should be running as. The UID must have sufficient rights to read from the Docker socket.
PGID	7077	GID of the user dns-exporter should be running as. You must set the PUID if you want to set the PGID variable.
EXPORTER_ARGS		Command line arguments for the exporter binary

Exposed ports

Port	Description
9119/tcp	Prometheus metrics over HTTP

Volumes

The container does not expose any volumes.

Security

The container is regularly scanned for vulnerabilities and updated. Further info can be found in the Security tab.

Container user

The container supports privilege drop. Even though the container starts as root, it will use the permissions only to perform the initial set up. The dns-exporter process runs as UID/GID provided in the PUID and PGID environment variables.

⚠️ Do not change the container user directly using the user Docker compose property or using the --user argument. This would break the privilege drop logic.