Configuration

CLI options

Usage of /bin/registrator:
  /bin/registrator [options] <registry URI>

  -cleanup=false:           Remove dangling services
  -deregister="always":     Deregister exited services "always" or "on-success"
  -explicit=false:          Only register containers that have SERVICE_NAME set
  -internal=false:          Use internal ports instead of published ones
  -ip="":                   IP for ports mapped to the host
  -ip-from-container=false: Use container IP instead of host IP for service registration
  -resync=0:                Frequency with which services are resynchronized
  -useIpFromLabel="":       Use IP stored in the given container label instead of the host IP
  -retry-attempts=0:        Max retry attempts to establish a connection with the backend. Use -1 for infinite retries
  -retry-interval=2000:     Interval (in milliseconds) between retry attempts
  -tags="":                 Append tags for all registered services (supports Go template)
  -ttl=0:                   TTL for services (default is no expiry)
  -ttl-refresh=0:           Frequency with which service TTLs are refreshed

Cleanup support

The -cleanup flag removes dangling registry entries that no longer correspond to running Docker containers. Cleanup requires backend support for listing existing registrations.

Cleanup only removes registrations whose service ID can be matched to Registrator's service ID format. Backends that cannot list registrations, or that store records without the original service ID, cannot be cleaned safely.

Backend	Cleanup support	Notes
`consul://`	Supported	Lists services through the Consul agent API
`consulkv://`	Supported	Lists keys under the configured KV path
`etcd://`	Supported	Lists keys under the configured etcd v3 prefix
`etcd-legacy://`	Supported	Lists keys recursively through the legacy etcd API
`coredns://`	Not currently supported	SkyDNS keys do not preserve the original Registrator service ID safely
`zookeeper://`	Supported	Lists znodes that include the Registrator service ID in their payload

ZooKeeper cleanup applies to registrations created with payloads that include the service ID. Older ZooKeeper registrations without that field are ignored instead of being guessed.

Service variables

Registrator reads configuration from container environment variables prefixed with SERVICE_.

Identity

Variable	Description
`SERVICE_NAME`	Override the service name
`SERVICE_TAGS`	Comma-separated tags. Supports Go templates (e.g. `{{.Config.Hostname}}`)
`SERVICE_IGNORE`	Ignore this container entirely

Per-port variables

Variable	Description
`SERVICE_<port>_NAME`	Name for a specific port
`SERVICE_<port>_<protocol>_NAME`	Name for a specific port and protocol (e.g. `SERVICE_80_tcp_NAME`)
`SERVICE_<N>-<M>_IGNORE`	Ignore all ports in range N–M (e.g. `SERVICE_10000-20000_IGNORE=true`)

Health checks

Variable	Description
`SERVICE_CHECK_HTTP`	HTTP health check path
`SERVICE_CHECK_HTTPS`	HTTPS health check path
`SERVICE_CHECK_TCP`	TCP health check
`SERVICE_CHECK_SCRIPT`	Script health check (space-separated args)
`SERVICE_CHECK_GRPC`	gRPC health check
`SERVICE_CHECK_TTL`	TTL-based health check
`SERVICE_CHECK_INTERVAL`	Health check interval (default `10s`)
`SERVICE_CHECK_TIMEOUT`	Health check timeout
`SERVICE_CHECK_TLS_SKIP_VERIFY`	Skip TLS verification for health checks

Consul-specific

Variable	Description
`SERVICE_ENABLE_TAG_OVERRIDE`	Allow external agents to update tags without registrator overwriting them