open-consul/contributing/cli

Command-Line Interface (CLI)

This section is a work in progress.

The consul binary provides a CLI for interacting with the HTTP API. Some commands may also exec other processes or generate data used by Consul (ex: tls certificates). The agent command is responsible for starting the Consul agent.

The cli reference in Consul user documentation has a full reference to all available commands.

Code

The CLI entrypoint is main.go and the majority of the source for the CLI is under the command directory. Each subcommand is a separate package under command. The CLI uses github.com/mitchellh/cli as a framework, and uses the flag package from the stdlib for command line flags.

Important notes

The cli.Ui wraps an io.Writer for both stdout and stderr. At the time of writing both Info and Output go to stdout. Writing Info to stdout has been a source of a couple bugs. To prevent these bugs in the future it is recommended that Info should no longer be used. Instead, send all information messages to stderr by using Warn.