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Go

The Go module gives a Go workspace one shared way to test, lint, and run go generate. It scans the workspace for go.mod files, treats each one as a Go module, and exposes workspace-level functions that run across all of them — a good fit for monorepos, service repos, and libraries with generated code, especially when several modules should share one Go version and the same CI checks.

Official module: dagger/go

Add it to your workspace​

dagger install github.com/dagger/go

Run the checks​

dagger check              # run every check in the workspace
dagger check go:test-all  # run Go tests across every module
dagger check go:lint-all  # run golangci-lint across every module

test-all and lint-all discover every go.mod in the workspace, treat each as a Go module, and run against all of them. Tests run through an OpenTelemetry-aware runner, so individual Go tests appear as spans in the Dagger TUI and Dagger Cloud. Lint runs a pinned golangci-lint and picks up each module's .golangci.* config.

Generate code​

Run the generator when generated Go files are part of normal development — mocks, embedded assets, protobuf output, or anything produced by go generate:

dagger generate go:generate-all

generate-all runs only in modules that contain a //go:generate directive, and returns the result as a changeset to review before applying.

Configure it​

List the current settings with dagger settings go, then change one with dagger settings go <key> <value>. They live in dagger.toml under [modules.go.settings]:

  • version (default 1.26): the Go toolchain version used to build the test and generate containers (golang:<version>-alpine). Set this so every module is tested and generated against the same Go version. Lint uses a pinned golangci-lint image and is unaffected.
  • includeExtraFiles (default empty): extra workspace-root path patterns mounted alongside each module's Go source. Go source, go.mod/go.sum/go.work, and testdata/ directories are already included automatically; use this for inputs those patterns miss, such as embedded non-Go assets, generator inputs, or fixtures kept outside testdata/.
  • lint, test, and generate (each defaults to ["**"]): module-root selector arrays for lint-all, test-all, and generate-all. A bare pattern includes modules, a !-prefixed pattern excludes them, and exclusions always win. "**" and "*" match every module; "path" and "path/**" match the module at path and any modules below it. With no positive pattern, every module is included unless excluded, so ["!**"] disables that workflow everywhere.
# Pin the Go version for the whole workspace
dagger settings go version 1.25

List-valued settings are edited directly in dagger.toml:

[modules.go.settings]
version = "1.25"
includeExtraFiles = ["Makefile", "tools/**"]
lint = ["!**"] # Disable linting for all modules
test = ["**", "!legacy-service"] # Test all modules except legacy-service and modules below it

Working with other modules​

Reach for this module whenever the repo contains one or more Go modules, especially when they should share the same Go version and CI checks. To exclude a single module from a workflow, add a !-prefixed module path to the corresponding selector array rather than splitting the repo into separate check systems.