dgiot/lib-extra

EMQX Extra plugin apps

This directory keeps a plugins file which defines all the approved external plugins from open-source community.

The (maybe broken) symlinks are keept to help testing plugins in this umbrella project.

Add a plugin to the project

Add plugin_foo as a rebar3 dependency in plugins file.

e.g. For an Erlang plugin named plugin_foo:

{erlang_plugins,
  [ {plugin_foo, {git, "https://github.com/bar/plugin-foo.git", {tag, "0.1.0"}}}
  ]
}.

Note: The -emqx_plugin(?MODULE) attribute should be added to <plugin-name>_app.erl file to indicate that this is an EMQX Broker plugin.

For example:

%% plugin_foo_app.erl
-emqx_plugin(?MODULE)

Build a release

$ export EMQX_EXTRA_PLUGINS=plugin_foo,plugin_bar
$ make

If all goes as expected, there should be two directories in the release:

_build/emqx/rel/emqx/lib/plugin_foo-<..vsn..>/

Run your code

Start the node (interactive mode)

./_build/emqx/rel/emqx/bin/emqx console

Load the plugin with command:

./_build/emqx/rel/emqx/bin/emqx_ctl plugins load plugin_foo

Test the plugin

If the plugin is added as a rebar dependency, it should be cloned to _build/default/lib/plugin_foo.

Before you can test it, you need to make sure there is a symlink in lib-extra pointing to the clone. For instance, the emqx_plugin_template plugin is linked like this

emqx_plugin_template -> ../_build/default/lib/emqx_plugin_template/

To run its teste cases:

./rebar3 eunit --dir lib-extra/plugin_foo
mkae lib-extra/plugin_foo-ct

NOTE: we should depth=1 shallow clone into _build/ directory, for plugins being actively developed, you can place the clone in lib-extra/

Caveats

• Elixir dependency in Erlang is not quite nicely supported as incremental builds, meaning you will not be able to edit the code in this project and get recompiled in the next make command.

• To have the plugin enabled/loaded by default, you can include it in the template data/loaded_plugins.tmpl