Go Mod Exists + Go Collector

✓ Guardrail ↓ Collector Stable Devex Build And Ci

Enforce Go Mod Exists using data collected by Go Collector. Automatically check devex build and ci standards on every PR.

Guardrail: Ensures the project has a go.mod file for module management. Required for all Go projects using modules.

Data Source: Analyze Go projects to collect module info, dependencies, test coverage, and golangci-lint results. Enforce Go-specific engineering standards.

Get Started View on GitHub

How Go Collector Powers This Guardrail

The Go Collector gathers metadata from your languages, build systems. This data flows into Lunar's Component JSON, where the Go Mod Exists guardrail evaluates it against your standards.

When enabled, this check runs automatically on every PR and in AI coding workflows, providing real-time enforcement with actionable feedback.

↓ Go Collector Gathers Data Collector

Extracts metadata from code, configs, and tool outputs

{ } Component JSON

Data centralized in structured format for evaluation

✓ Go Mod Exists Checks Guardrail

Pass/fail result with actionable feedback in PRs

Quick Start Configuration

Add both the collector and policy to your lunar-config.yml to enable this guardrail.

📄 lunar-config.yml

# Step 1: Enable the Go Collector
collectors:
  - uses: github://earthly/lunar-lib/collectors/golang@v1.0.0
    # with: ...

# Step 2: Enable the Go Project Guardrails
policies:
  - uses: github://earthly/lunar-lib/policies/golang@v1.0.0
    include: [go-mod-exists]
    # with: ...

What Go Collector Collects

This collector gathers the following data that the Go Mod Exists guardrail evaluates.

Collector ci-before-command

`cicd`

Records every Go command executed in CI pipelines along with the Go version. Writes command strings and version info to .lang.go.cicd for audit trails and build reproducibility analysis.

Collector ci-before-command

`test-scope`

Determines whether go test runs recursively (./...) or targets specific packages. Writes scope to .lang.go.tests.scope as "recursive" or "package" to verify comprehensive test execution in CI.

Collector ci-after-command

`test-coverage`

Extracts coverage percentage from go test -coverprofile output after tests complete. Parses the coverage profile file, runs go tool cover -func to calculate total percentage, and writes results to .lang.go.tests.coverage including the raw profile.

Collector code

`project`

Analyzes Go project structure by detecting go.mod, go.sum, vendor directory, and goreleaser configuration. Extracts the module path and Go version from go.mod using go list. Writes project metadata to .lang.go with build system info.

View all 6 collectors in Go Collector →

Example Data Flow

Here's an example of the data that Go Collector writes to the Component JSON, which Go Mod Exists then evaluates.

{ } component.json From Go Collector

{
  "lang": {
    "go": {
      "module": "github.com/acme/myproject",
      "version": "1.21",
      "build_systems": ["go"],
      "go_mod_exists": true,
      "go_sum_exists": true,
      "vendor_exists": false,
      "goreleaser_exists": true,
      "golangci_lint": {
        "passed": false,
        "config_exists": true,
        "exit_code": 1,
        "output": "main.go:42:5: unused variable 'x' (unused)"
      },
      "source": { "tool": "go", "integration": "code" },
      "cicd": {
        "cmds": [{ "cmd": "go test ./...", "version": "1.21.5" }],
        "source": { "tool": "go", "integration": "ci" }
      },
      "tests": {
        "scope": "recursive",
        "coverage": {
          "percentage": 78.5,
          "profile_path": "coverage.out",
          "source": { "tool": "go cover", "integration": "ci" }
        }
      },
      "dependencies": {
        "direct": [
          { "path": "github.com/stretchr/testify", "version": "v1.8.4", "indirect": false }
        ],
        "transitive": [
          { "path": "github.com/davecgh/go-spew", "version": "v1.1.1", "indirect": true }
        ],
        "source": { "tool": "go mod", "integration": "code" }
      },
      "lint": {
        "warnings": [
          { "file": "main.go", "line": 42, "column": 5, "message": "unused variable 'x'", "linter": "unused" }
        ],
        "linters": ["golangci-lint"],
        "source": { "tool": "golangci-lint", "integration": "code" }
      }
    }
  }
}

Configuration Options

Go Collector Inputs

Input	Required	Default	Description
`lint_timeout`	Optional	`10m`	Timeout for golangci-lint (e.g., 5m, 10m)

Go Project Guardrails Inputs

Input	Required	Default	Description
`min_go_version`	Optional	`1.21`	Minimum required Go version (e.g., "1.21", "1.22")
`min_go_version_cicd`	Optional	`1.21`	Minimum required Go version for CI/CD commands (e.g., "1.21", "1.22")
`vendoring_mode`	Optional	`none`	Vendoring enforcement mode: - "required": Fail if vendor/ directory doesn't exist - "forbidden": Fail if vendor/ directory exists - "none": Skip vendoring check (default)

Learn More

Guardrail · Go Project Guardrails Go Mod Exists View all compatible integrations

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Collector Go Collector View full documentation

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