plugins

$ packer plugins -h
Usage: packer plugins <subcommand> [options] [args]
  This command groups subcommands for interacting with Packer plugins.

Related but not under the "plugins" command :

- "packer init <path>" will install all plugins required by a config.

Subcommands:
    install      Install latest Packer plugin [matching version constraint]
    installed    List all installed Packer plugin binaries
    remove       Remove Packer plugins [matching a version]
    required     List plugins required by a config