github-actions

Hosts GitHub Actions that can be imported by other repositories.

go-toolchain-setup

Selects the Go toolchain declared by a module's go.mod file (or an explicitly specified version), acquires it using Go's native toolchain management, and activates it for subsequent steps.

The toolchain is selected using the rules of the github.com/palantir/pkg/gotoolchain package:

1. If the toolchain directive is present and is not default, its value is used.
2. Otherwise, the go directive is used with a go prefix, appending .0 to Major.Minor versions (go 1.27 selects go1.27.0).

go.work files are not consulted. The selection logic is implemented by go-toolchain-setup/gotoolchain.sh, which is distributed from the gotoolchain module and must not be modified in this repository.

The selected toolchain is acquired by running the bootstrap go executable on PATH with GOTOOLCHAIN set to the selected version. This uses the bootstrap's bundled toolchain or a version-named executable on PATH if either matches, and otherwise downloads the toolchain through the configured module proxy. A Go 1.21 or later go executable must therefore be on PATH before this action runs. The action does not set GOPROXY, GOSUMDB or related variables: set them in the job environment when downloads must go through a different proxy or checksum database.

After the action runs, the selected toolchain's bin directory is first on PATH, GOROOT is set to the selected toolchain, and GOTOOLCHAIN=local and GOWORK=off are set so that subsequent Go commands do not switch toolchains.

Inputs:

Input	Default	Description
working-directory	.	Directory containing the go.mod file that determines the toolchain.
go-version	""	Exact toolchain version to use instead of selecting from go.mod (for example go1.27.3).
if-no-go-mod	fail	Behavior when go.mod does not exist and go-version is empty: fail, or skip to set found=false and make no changes.

Outputs:

Output	Description
found	true if a toolchain was selected and activated, false if setup was skipped.
version	The selected toolchain version (for example go1.27.3).
goroot	The GOROOT of the activated toolchain.

Example usage:

  - uses: actions/checkout@v4
  - id: go
    uses: palantir/github-actions/go-toolchain-setup@<version>
  - run: echo "Using ${{ steps.go.outputs.version }}"