»Consul Force Leave

Command: consul force-leave

Corresponding HTTP API Endpoint: [PUT] /v1/agent/force-leave/:node

The force-leave command forces a member of a Consul cluster to enter the "left" state. The purpose of this method is to force-remove a node that has failed or was shutdown without a graceful leave.

Consul periodically tries to reconnect to "failed" nodes in case failure was due to a network partition. After some configured amount of time (by default 72 hours), Consul will reap "failed" nodes and stop trying to reconnect. The force-leave command can be used to transition the "failed" nodes to a "left" state more quickly, as reported by consul members.

This can be particularly useful for a node that was running as a server, as it will eventually be removed from the Raft configuration by the leader.

Note that for force-leave to take full effect the target node's agent must have shutdown permanently. If the agent is alive and reachable then it will not be removed from the datacenter's member list nor from the raft configuration. Additionally, if the agent returns after transitioning to the "left" state, but before it is reaped from the member list, then it will rejoin the cluster.

The table below shows this command's required ACLs. Configuration of blocking queries and agent caching are not supported from commands, but may be from the corresponding HTTP endpoint.

ACL Required
`operator:write`

Usage

Usage: consul force-leave [options] node

API Options

-ca-file=<value> - Path to a CA file to use for TLS when communicating with Consul. This can also be specified via the CONSUL_CACERT environment variable.
-ca-path=<value> - Path to a directory of CA certificates to use for TLS when communicating with Consul. This can also be specified via the CONSUL_CAPATH environment variable.
-client-cert=<value> - Path to a client cert file to use for TLS when verify_incoming is enabled. This can also be specified via the CONSUL_CLIENT_CERT environment variable.
-client-key=<value> - Path to a client key file to use for TLS when verify_incoming is enabled. This can also be specified via the CONSUL_CLIENT_KEY environment variable.
-http-addr=<addr> - Address of the Consul agent with the port. This can be an IP address or DNS address, but it must include the port. This can also be specified via the CONSUL_HTTP_ADDR environment variable. In Consul 0.8 and later, the default value is http://127.0.0.1:8500, and https can optionally be used instead. The scheme can also be set to HTTPS by setting the environment variable CONSUL_HTTP_SSL=true. This may be a unix domain socket using unix:///path/to/socket if the agent is configured to listen that way.
-tls-server-name=<value> - The server name to use as the SNI host when connecting via TLS. This can also be specified via the CONSUL_TLS_SERVER_NAME environment variable.
-token=<value> - ACL token to use in the request. This can also be specified via the CONSUL_HTTP_TOKEN environment variable. If unspecified, the query will default to the token of the Consul agent at the HTTP address.
-token-file=<value> - File containing the ACL token to use in the request instead of one specified via the -token argument or CONSUL_HTTP_TOKEN environment variable. This can also be specified via the CONSUL_HTTP_TOKEN_FILE environment variable.

Examples

Remove a node named ec2-001-staging from the local agent's datacenter:

consul force-leave ec2-001-staging

When run on a server that is part of a WAN gossip pool, force-leave can remove failed servers in other datacenters from the WAN pool.

The identifying node-name in a WAN pool is [node-name].[datacenter]. Therefore, to remove a failed server node named server1 from datacenter us-east1, run:

consul force-leave server1.us-east1

Command Options

-prune - Removes failed or left agent from the list of members entirely. Added in Consul 1.6.2.
-wan - Exclusively leave the agent from the WAN gossip pool. Added in Consul 1.11.0.