Erlang.mk will create a release if it detects a Relx configuration file in the $(RELX_CONFIG) location. This defaults to $(CURDIR)/relx.config. You can override it by defining the variable before including Erlang.mk:

Relx does not need to be installed. Erlang.mk will download and build it automatically.

The Relx executable will be saved in the $(RELX) file. This location defaults to $(CURDIR)/relx and can be overriden.

You can specify additional Relx options using the RELX_OPTS variable. For example, to enable dev_mode:

While you can specify the output directory for the release in the Relx options directly, Erlang.mk provides a specific variable for it: RELX_OUTPUT_DIR. It defaults to the _rel directory. You can also override it:

Now that you’re all set, all you need to do is generate the release. As mentioned before, Erlang.mk will automatically generate it when it detects the $(RELX_CONFIG) file. This means the following command will also build the release:

If you need to generate the release, and only the release, the rel target can be used:

Erlang.mk provides a convenience function for running the release with one simple command:

This command will also build the project and generate the release if they weren’t already. It starts the release in console mode, meaning you will also have a shell ready to use to check things as needed.