Changelog

All notable changes to this project are documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

1.0.0 - 2026-09-28

Castle 1.0 resolves each target release's configuration with that release's own code and config providers, and adds upgrades that restart the emulator under an external supervisor. It requires Forecastle 1.x and Elixir 1.18 or later. Two changes break existing pipelines: mix forecastle.relup is now mix castle.relup, and Castle.generate/1 has been removed.

Added

• Castle.customize/1, the release integration API. It adds Forecastle's steps around :assemble and defaults missing release steps to [:assemble, :tar]. (#12)
• Relup generation during assembly. Name baselines in upgrade_from: (a shipped tar: archive, an assembled rel: release or a ref: git ref) and one mix release produces a tarball carrying both its upgrade and downgrade instructions. (forecastle#28, forecastle#40)
• Upgrade tooling from Forecastle:
  • mix castle.appup, which checks that an appup covers every module that changed between two builds. (forecastle#27)
  • mix castle.appup.gen, which drafts missing appup entries for review, including for dependencies with --app <dep>. (forecastle#29, forecastle#30)
  • mix castle.relup --dry-run, which reports whether a transition can be hot without writing a relup. (forecastle#31)
  • Forecastle.UpgradeCase and Forecastle.Deployment, a harness for testing upgrades against a shipped artifact. (forecastle#32)
• Target configuration resolved in a temporary VM running the target release's boot script, emulator and config providers. (#13)
• Castle.upgradable/0, and matching checks in unpack/1 and install/1, which refuse nodes running a release record synthesised by :release_handler and explain how to recover.
• Castle.running/1, which confirms that a version is running and has finished booting.
• One-stage restart_emulator upgrades under systemd, Docker, Kubernetes and other external supervisors. (#14)

Changed

• Breaking: mix forecastle.relup is now mix castle.relup. There is no compatibility alias, so build pipelines calling the old name must be updated. mix compile.appup is unchanged. (forecastle#24)
• Release commands raise Castle.Error on a refusal or an error from :release_handler, so bin/castle exits non-zero. Output on success is unchanged. (#10)
• Installs and commits on a node are serialised with configuration resolution.
• The minimum supported Elixir version is 1.18.

Removed

• Breaking: Castle.generate/1 and the build.config configuration path. Each target release is now configured by its own config providers.

Fixed

• install/1 reports an upgrade that replaces the emulator, kernel, stdlib or sasl instead of crashing with CaseClauseError.
• releases/0 prints nothing when no release is installed instead of raising Enum.EmptyError.
• make_releases/0 reports RELEASES read and write errors instead of raising MatchError, and finds the release directory from the running emulator rather than the current working directory.
• Resolved configuration is staged with owner-only permissions and published atomically, keeping the original sys.config mode.
• Commands that modify a deployment refuse a release whose emulator root differs from the release root, including one built with include_erts: false, instead of letting :release_handler modify the shared Erlang installation.

0.3.1 - Jan 19, 2025

• Switch to charlist sigils

0.3.0 - May 27, 2023

• Move build time support into Forecastle

0.2.3 - May 21, 2023

• Fix bug in shell script that prevented execution on Linux

0.2.2 - May 21, 2023

• Update Changelog

0.2.1 - May 21, 2023

• Update README

0.2.0 - May 21, 2023

• Added support for Config Provider expansion

0.1.3 - May 16, 2023

• Initial revision