This plugin provides an API for various common plugin tasks (such as processing deps and alt_deps, generate command callback functions at runtime, etc). Using this plugin, you can guarantee that all your other plugins declared as deps, will be available on the code path for all commands, including transient deps.

In order to achieve this, you need to do one of two things in your project.

1. Expect users to install rebar_plugin_manager to $ERL_LIBS or code:lib_dir
2. Include rebar_plugin_manager as a dependency, and point plugin_dir at it

In the former case, you should at least enforce the presence of the plugin:

{deps, [{rebar_plugin_manager, "0.0.1"}]}.
{plugins, [rebar_plugin_manager]}.

In the latter case, you will need to specify a source (or use alt_deps) to ensure rebar pulls the plugin during get-deps or install-deps, then point your plugin_dir config to the source directory like so:

{deps, [{rebar_plugin_manager, "0.0.1"}]}.
{alt_repositories, [
    {rebar_plugin_manager,
        {github, "hyperthunk", "v0.0.1"}},
]}.

{plugins, [rebar_plugin_manager]}.
{plugin_dir, "deps/rebar_plugin_manager/src"}.

Naturally you can't put your own build plugins somewhere custom using this mechanism, which is annoying. To compensate for this, rebar_plugin_manager provides an API by which you can hook in additional directories for loading plugins from source.

{plugins, [rebar_plugin_manager]}.
{plugin_dir, "deps/rebar_plugin_manager/src"}.

{plugin_sources, ["build/plugins", "test/plugins"]}.

When using this API, all exported commands (from the plugins) are exposed via the rebar_plugin_manager module itself (i.e., it exports a handler which in turn calls the requisite plugin module).

There is also limited support for loading plugins from remote sources, although this only works for single module plugins (i.e., where there is only one .erl file to download) and is far less flexible than using something like alt_deps.

The rebar_plugin_manager requires a recent version of rebar with support for plugins hooking into the Module:preprocess/2 mechanism.

Include the following tuple in your rebar deps:

{deps, [{rebar_plugin_manager, ".*", {git,
    "git://github.com/hyperthunk/rebar_plugin_manager.git"}}]}.

Then you will be able to fetch and install the plugin (locally) with rebar. Alternatively, you may put the plugin into your ERL_LIBS path somewhere and use it in many projects. This can be done manually, or using a package manager:

user@host$ epm install hyperthunk/rebar_plugin_manager    # or
user@host$ sutro install hyperthunk/rebar_plugin_manager  # or
user@host$ agner install rebar_plugin_manager