Generates a new release tarball for antikythera instance using relx.

Notes on the implementation details of this task:

• Release generation is basically done under rel_erlang-*/. During tests (i.e. when ANTIKYTHERA_COMPILE_ENV=local), files are generated under rel_local_erlang-*/.

  • Erlang/OTP major version number is included in the path in order to distinguish artifacts generated by different OTP releases. No binary compatibility is maintained by major version release of Erlang/OTP due to precompilation of Elixir’s regex sigils. For more details see documentation for Regex module.
• Generated releases are placed under rel(_local)_erlang-*/<antikythera_instance>/releases/.
• If no previous releases found, this task generates a new release from scratch (i.e. without relup). If any previous releases exist, relup file to upgrade from the latest existing release to the current release is also generated.

• Making a new release tarball consists of the following steps:

  • Preparation

    • .beam and .app files.
    • vm.args: resides in the git repository and is copied to the release by relx’s overlay mechanism.
    • sys.config: generated from mix config and then copied to the release by relx’s overlay mechanism.
    • relx.config: generated from relx.config.eex.

  • Release generation

    • If needed, generate .appup files and relup file.
    • Generate a new release from the input files by :relx.do/2.

  • Cleanup

    • Move some files and apply patch to boot script, in order to suit our needs.
    • Make a tarball. This step also uses :relx.do/2.
    • Remove temporary files.