Coursier setup GitHub Action

A GitHub Action to install Coursier and use it to install Java and Scala CLI tools.

It can be useful if you want to install a specific version of JVM or use a build tool like mill or seed.

Inspired by olafurpg/setup-scala and the blog post Single command Scala setup by Alex Archambault (author of Coursier).

Features

• run it on any platform: Linux, MacOS, Windows
• install any JVM you need
• setup the build tool of your choice: sbt, mill, seed, etc.
• install other common Scala CLI tools: Ammonite, Bloop, giter8, etc.

Inputs

• jvm (optional): JVM to install

  • one of the options from cs java --available.
  • if left empty either the existing JVM will be used or Coursier will install its default JVM.

• jvm-index (optional): The JVM index source

  • arbitrary URL containing the JVM index source like in cs java --available --jvm-index https://url/of/your/index.json.
  • if left empty the coursier index will be used as default JVM index source

• apps (optional): Scala apps to install (sbtn by default)

  • space separated list of app names (from the main channel)

• version (optional): Coursier version to install

  • a release version such as 2.1.25-M26 (defaults to a recent release when left empty)
  • nightly installs the latest nightly build

• customRepositories (optional): ''

  • Pipe separated list of repositories to supply to coursier

• disableDefaultRepos (optional): 'false'

  • Whether or not to pass the --no-default flag to coursier

• mirrors (optional): ''

  • Newline-separated list of from=to entries written to ~/.config/coursier/mirror.properties before any cs invocation.
  • The from side may be a comma-separated list of source URLs.
  • Unlike customRepositories / disableDefaultRepos, mirrors are applied at the resolver level to every repository coursier sees — including ones declared inside app descriptors that customRepositories cannot override.
  • See coursier mirrors.

• extraJvmArgs (optional): ''

  • Space-separated list of -D JVM property args passed to every cs invocation. The -J prefix is added automatically if missing.
  • e.g. -Dhttps.proxyHost=proxy.example.com -Dhttps.proxyPort=8080

• launcher (optional): Coursier launcher

  • Leave empty (default) to install the default native binary launcher when available. On Windows ARM64, that is the jpackage JVM distribution (cs-aarch64-pc-win32-jvm.zip), which embeds its own runtime.
  • thin (or jvm) selects the thin JVM launcher and assembly selects the assembly (fat JAR) launcher. These require Java to be installed beforehand.
  • Other values select a native launcher flavor. Available flavors include container, compat, and static; for example, container downloads the launcher whose filename ends in -container.
  • The action fails when the selected launcher is not available for the selected version and platform.

• preferredLauncher (optional): Preferred Coursier launcher flavor

  • Downloads the same launcher as launcher, but falls back to the default launcher with a warning when the flavored download returns a 4xx HTTP response.
  • The JVM launcher values thin, jvm, and assembly are rejected; pass those via launcher.
  • Cannot be used together with launcher.

• useContainerImage (optional): Deprecated alias for launcher: container.

Example with custom inputs

  steps:
    - uses: actions/checkout@v4
    - uses: coursier/setup-action@v3
      with:
        jvm: adopt:11
        jvm-index: https://url/of/your/index.json
        apps: sbtn bloop ammonite
        disableDefaultRepos: true
        customRepositories: https://packages.corp.com/maven
        mirrors: |
          https://repo1.maven.org/maven2=https://packages.corp.com/maven

Nightly Coursier

  steps:
    - uses: actions/checkout@v4
    - uses: coursier/setup-action@v3
      with:
        version: nightly

Outputs

• cs-version: version of the installed Coursier (should be the latest available)

Caching

This action should work well with the official Coursier cache-action. For example:

  steps:
    - uses: actions/checkout@v4
    - uses: coursier/cache-action@v8
    - uses: coursier/setup-action@v3