Docker DNS Resolver

This is a simple DNS resolver that syncs Docker container labels to one or more DNS providers (currently AWS Route53 and DigitalOcean).

Container labels

• domain (required) — the FQDN to register for the container, e.g. domain=api.example.com.
• dns.provider (optional) — which configured provider should handle the record, e.g. dns.provider=route53. If omitted, the value of DEFAULT_DNS_PROVIDER is used; if neither is set, the container is skipped with a log line.

Environment variables

• ROOT_RECORD (required) — the target the CNAMEs point at, e.g. the load balancer hostname.
• DNS_PROVIDERS (required) — comma-separated list of providers to enable, e.g. route53,digitalocean.
• DEFAULT_DNS_PROVIDER (optional) — fallback for containers without a dns.provider label. Must name a provider listed in DNS_PROVIDERS.
• AWS_ROUTE53_HOSTED_ZONE_ID (route53, optional) — pin to a specific zone and skip ListHostedZones. Standard AWS SDK env vars (AWS_REGION, AWS_ACCESS_KEY_ID, ...) configure credentials.
• DO_TOKEN (digitalocean, required when enabled) — a DigitalOcean personal access token with read+write scope on the Domains resource.

Example

docker run -d \
  --label domain=api.example.com \
  --label dns.provider=digitalocean \
  my/image