Consul Commands (CLI)

Consul is controlled via a very easy to use command-line interface (CLI). Consul is only a single command-line application: consul. This application then takes a subcommand such as “agent” or “members”. The complete list of subcommands is in the navigation to the left.

The consul CLI is a well-behaved command line application. In erroneous cases, a non-zero exit status will be returned. It also responds to -h and --help as you’d most likely expect. And some commands that expect input accept “-“ as a parameter to tell Consul to read the input from stdin.

To view a list of the available commands at any time, just run consul with no arguments:

  1. $ consul
  2. Usage: consul [--version] [--help] <command> [<args>]
  4. Available commands are:
  5.     acl            Interact with Consul's ACLs
  6.     agent          Runs a Consul agent
  7.     catalog        Interact with the catalog
  8.     connect        Interact with Consul Connect
  9.     debug          Records a debugging archive for operators
  10.     event          Fire a new event
  11.     exec           Executes a command on Consul nodes
  12.     force-leave    Forces a member of the cluster to enter the "left" state
  13.     info           Provides debugging information for operators.
  14.     intention      Interact with Connect service intentions
  15.     join           Tell Consul agent to join cluster
  16.     keygen         Generates a new encryption key
  17.     keyring        Manages gossip layer encryption keys
  18.     kv             Interact with the key-value store
  19.     leave          Gracefully leaves the Consul cluster and shuts down
  20.     lock           Execute a command holding a lock
  21.     login          Login to Consul using an auth method
  22.     logout         Destroy a Consul token created with login
  23.     maint          Controls node or service maintenance mode
  24.     members        Lists the members of a Consul cluster
  25.     monitor        Stream logs from a Consul agent
  26.     operator       Provides cluster-level tools for Consul operators
  27.     reload         Triggers the agent to reload configuration files
  28.     rtt            Estimates network round trip time between nodes
  29.     services       Interact with services
  30.     snapshot       Saves, restores and inspects snapshots of Consul server state
  31.     tls            Builtin helpers for creating CAs and certificates
  32.     validate       Validate config files/directories
  33.     version        Prints the Consul version
  34.     watch          Watch for changes in Consul

To get help for any specific command, pass the -h flag to the relevant subcommand. For example, to see help about the join subcommand:

  1. $ consul join -h
  2. Usage: consul join [options] address ...
  4.   Tells a running Consul agent (with "consul agent") to join the cluster
  5.   by specifying at least one existing member.
  7. HTTP API Options
  9.   -http-addr=<address>
  10.      The `address` and port of the Consul HTTP agent. The value can be
  11.      an IP address or DNS address, but it must also include the port.
  12.      This can also be specified via the CONSUL_HTTP_ADDR environment
  13.      variable. The default value is http://127.0.0.1:8500. The scheme
  14.      can also be set to HTTPS by setting the environment variable
  15.      CONSUL_HTTP_SSL=true.
  17.   -token=<value>
  18.      ACL token to use in the request. This can also be specified via the
  19.      CONSUL_HTTP_TOKEN environment variable. If unspecified, the query
  20.      will default to the token of the Consul agent at the HTTP address.
  22. Command Options
  24.   -wan
  25.      Joins a server to another server in the WAN pool.

Autocompletion

The consul command features opt-in subcommand autocompletion that you can enable for your shell with consul -autocomplete-install. After doing so, you can invoke a new shell and use the feature.

For example, assume a tab is typed at the end of each prompt line:

  1. $ consul e
  2. event  exec
  4. $ consul r
  5. reload  rtt
  7. $ consul operator raft
  8. list-peers   remove-peer

Environment Variables

In addition to CLI flags, Consul reads environment variables for behavior defaults. CLI flags always take precedence over environment variables, but it is often helpful to use environment variables to configure the Consul agent, particularly with configuration management and init systems.

These environment variables and their purpose are described below:

CONSUL_HTTP_ADDR

This is the HTTP API address to the local Consul agent (not the remote server) specified as a URI with optional scheme:

  1. CONSUL_HTTP_ADDR=127.0.0.1:8500

or as a Unix socket path:

  1. CONSUL_HTTP_ADDR=unix:///var/run/consul_http.sock

If the https:// scheme is used, CONSUL_HTTP_SSL is implied to be true.

CONSUL_HTTP_TOKEN

This is the API access token required when access control lists (ACLs) are enabled, for example:

  1. CONSUL_HTTP_TOKEN=aba7cbe5-879b-999a-07cc-2efd9ac0ffe

CONSUL_HTTP_TOKEN_FILE

This is a path to a file containing the API access token required when access control lists (ACLs) are enabled, for example:

  1. CONSUL_HTTP_TOKEN_FILE=/path/to/consul.token

CONSUL_HTTP_AUTH

This specifies HTTP Basic access credentials as a username:password pair:

  1. CONSUL_HTTP_AUTH=operations:JPIMCmhDHzTukgO6

CONSUL_HTTP_SSL

This is a boolean value (default is false) that enables the HTTPS URI scheme and SSL connections to the HTTP API:

  1. CONSUL_HTTP_SSL=true

CONSUL_HTTP_SSL_VERIFY

This is a boolean value (default true) to specify SSL certificate verification; setting this value to false is not recommended for production use. Example for development purposes:

  1. CONSUL_HTTP_SSL_VERIFY=false

CONSUL_CACERT

Path to a CA file to use for TLS when communicating with Consul.

  1. CONSUL_CACERT=ca.crt

CONSUL_CAPATH

Path to a directory of CA certificates to use for TLS when communicating with Consul.

  1. CONSUL_CAPATH=ca_certs/

CONSUL_CLIENT_CERT

Path to a client cert file to use for TLS when verify_incoming is enabled.

  1. CONSUL_CLIENT_CERT=client.crt

CONSUL_CLIENT_KEY

Path to a client key file to use for TLS when verify_incoming is enabled.

  1. CONSUL_CLIENT_KEY=client.key

CONSUL_TLS_SERVER_NAME

The server name to use as the SNI host when connecting via TLS.

  1. CONSUL_TLS_SERVER_NAME=consulserver.domain

CONSUL_GRPC_ADDR

Like CONSUL_HTTP_ADDR but configures the address the local agent is listening for gRPC requests. Currently gRPC is only used for integrating Envoy proxy and must be enabled explicitly in agent configuration.

  1. CONSUL_GRPC_ADDR=127.0.0.1:8502

or as a Unix socket path:

  1. CONSUL_GRPC_ADDR=unix://var/run/consul_grpc.sock

If the agent is configured with TLS certificates, then the gRPC listener will require TLS and present the same certificate as the https listener. As with CONSUL_HTTP_ADDR, if TLS is enabled either the https:// scheme should be used, or CONSUL_HTTP_SSL set.

CONSUL_NAMESPACE

Enterprise only If you’re using Consul Enterprise namespaces you can set this for the CLI to explicitly use a single namespace. This is common across all Hashicorp products that support Enterprise namespaces.

  1. CONSUL_NAMESPACE=default