feat: extend GoModResolver to support any valid Go *.mod file by ivankatliarchuk · Pull Request #268 · apache/skywalking-eyes

ivankatliarchuk · 2026-04-02T17:27:29Z

Why: Projects using Go 1.24's tool dependency pattern (e.g. go.tool.mod) were failing with unable to find a resolver because the resolver only matched the hardcoded filename go.mod.

What:

GoModResolver.CanResolve now matches any *.mod file
GoModResolver.Resolve validates file content (module + go directives) and passes -modfile to go mod download for non-default mod files
Makefile: fix hardcoded ARCH=amd64 - now detects host arch via go env GOARCH, overridable for cross-compilation
Add golang_test.go covering CanResolve, Resolve validation, and ResolvePackageLicense

Current

DEBUG Base name: go.tool.mod
DEBUG Base name: go.tool.mod
DEBUG Base name: go.tool.mod
DEBUG Base name: go.tool.mod
ERROR unable to find a resolver to resolve dependency declaration file: ../source/self/go-work/fork-external-dns/go.tool.mod
ERROR one or more errors occurred checking license compatibility

With the Change

DEBUG Base name: go.mod
DEBUG Run command: /opt/homebrew/bin/go mod download, please wait
DEBUG Module size: 200
...
...
DEBUG Base name: go.tool.mod
DEBUG Run command: /opt/homebrew/bin/go mod download -modfile go.tool.mod, please wait
DEBUG Module size: 128
DEBUG Directory of github.com/a8m/envsubst is ../go/pkg/mod/github.com/a8m/envsubst@v1.4.3
DEBUG Directory of github.com/agext/levenshtein is ../go/pkg/mod/github.com/agext/levenshtein@v1.2.1
DEBUG Director

Log example

DEBUG Directory of sigs.k8s.io/randfill is ~/go/pkg/mod/sigs.k8s.io/randfill@v1.0.0
DEBUG 	- Found license: Apache-2.0
DEBUG Directory of sigs.k8s.io/yaml is ~/go/pkg/mod/sigs.k8s.io/yaml@v1.6.0
DEBUG 	- Found license: MIT and BSD-3-Clause and Apache-2.0

Signed-off-by: ivan katliarchuk <ivan.katliarchuk@gmail.com>

ivankatliarchuk · 2026-04-05T10:09:25Z

Hi @kezhenxu94

When you have time, could you have a look pls?

Copilot

Pull request overview

Extends the Go dependency resolver to recognize and handle non-default Go module files (e.g., go.tool.mod), including passing -modfile to go mod download, and adds tests plus a Makefile arch-detection tweak.

Changes:

Update GoModResolver.CanResolve to match *.mod files and add module-file validation + -modfile support during resolution.
Add Go resolver unit tests for CanResolve, invalid module-file validation behavior, and package license resolution.
Makefile now derives ARCH from go env GOARCH (overridable), and renames the uname variable used for OS detection.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
pkg/deps/golang.go	Broaden resolver matching to `*.mod`, validate modfile contents, and pass `-modfile` for non-`go.mod` files
pkg/deps/golang_test.go	New tests covering Go mod resolver matching/validation and license resolution behavior
Makefile	Detect host `GOARCH` by default rather than hardcoding `amd64`

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Copilot · 2026-04-05T10:13:17Z

pkg/deps/golang.go

+func validateGoModFile(file string) error {
+	content, err := os.ReadFile(file)
+	if err != nil {
+		return err
+	}
+	if !goModuleDirective.Match(content) || !goVersionDirective.Match(content) {
+		return fmt.Errorf("%v is not a valid Go module file", file)
+	}


validateGoModFile requires both module and go directives, but the go directive is optional in valid go.mod/*.mod files. This will reject legitimate modules and cause dependency resolution to fail. Consider parsing with golang.org/x/mod/modfile (and only requiring a valid module directive), or relax the validation to not require a go directive.

Copilot · 2026-04-05T10:13:17Z

pkg/deps/golang.go

+var (
+	goModuleDirective       = regexp.MustCompile(`(?m)^\s*module\s+\S`)
+	goVersionDirective      = regexp.MustCompile(`(?m)^\s*go\s+\d`)
+	possibleLicenseFileName = regexp.MustCompile(`(?i)^LICENSE|LICENCE(\.txt)?|COPYING(\.txt)?$`)


possibleLicenseFileName is missing grouping/anchoring, so it can match unintended names (e.g., any filename containing "LICENCE" anywhere) and ^LICENSE will also match directories like LICENSES. Since ResolvePackageLicense doesn't check info.IsDir(), this can lead to attempting to ReadFile on a directory and failing license resolution. Suggest anchoring the full pattern (e.g., ^(LICENSE|LICENCE)(\.txt)?$|^COPYING(\.txt)?$) and skipping directories before reading.

Suggested change

possibleLicenseFileName = regexp.MustCompile(`(?i)^LICENSE|LICENCE(\.txt)?|COPYING(\.txt)?$`)

possibleLicenseFileName = regexp.MustCompile(`(?i)^(LICENSE|LICENCE|COPYING)(\.txt)?$`)

this regex pre-existed the PR (it was just moved); the PR made it visible. I could fix it, as it's valid and a real bug.

Copilot · 2026-04-05T10:13:17Z

pkg/deps/golang.go

 				return err
 			}

+			logger.Log.Debugf("\t- Found license: %v", identifier)


Before os.ReadFile(licenseFilePath) earlier in this function, ensure the directory entry isn’t a directory (info.IsDir()), otherwise directories like LICENSES/ can be treated as license files and cause a hard error. (The current name regex also matches prefixes like LICENSE*.)

Copilot · 2026-04-05T10:13:18Z

pkg/deps/golang_test.go

+			t.Fatalf("expected 1 resolved, got %d", len(report.Resolved))
+		}
+		if report.Resolved[0].LicenseSpdxID != npmLicenseApache20 {
+			t.Errorf("expected %v, got %v", npmLicenseApache20, report.Resolved[0].LicenseSpdxID)
+		}


This test relies on npmLicenseApache20, which is declared in an unrelated NPM resolver test file. That coupling is fragile (e.g., if that file is renamed, moved, or build-tagged) and makes this test harder to understand in isolation. Prefer defining a local constant (or using a literal) in this file.

kezhenxu94 · 2026-04-05T10:14:59Z

@ivankatliarchuk can you please fix the CI

Signed-off-by: ivan katliarchuk <ivan.katliarchuk@gmail.com>

ivankatliarchuk · 2026-04-05T10:58:39Z

Done. I've added test-docker to Makefile directive. As running tests locally require maven installed.

Tested with

go test ./pkg/deps/ -run 'TestCanResolveGoMod|TestResolveGoModInvalidFile|TestResolvePackageLicense' -v

Green as well

Copilot

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

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kezhenxu94

Thank you!

ivankatliarchuk added 2 commits April 2, 2026 18:25

feat: extend GoModResolver to support any valid Go *.mod file

b5e0ec5

Signed-off-by: ivan katliarchuk <ivan.katliarchuk@gmail.com>

feat: extend GoModResolver to support any valid Go *.mod file

a2dc9ad

Signed-off-by: ivan katliarchuk <ivan.katliarchuk@gmail.com>

wu-sheng requested review from Copilot and kezhenxu94 April 5, 2026 10:10

wu-sheng added this to the 0.9.0 milestone Apr 5, 2026

Copilot started reviewing on behalf of wu-sheng April 5, 2026 10:10 View session

Copilot AI reviewed Apr 5, 2026

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feat: extend GoModResolver to support any valid Go *.mod file

c1b9b89

Signed-off-by: ivan katliarchuk <ivan.katliarchuk@gmail.com>

ivankatliarchuk requested a review from Copilot April 5, 2026 10:59

Copilot started reviewing on behalf of ivankatliarchuk April 5, 2026 11:00 View session

Copilot AI reviewed Apr 5, 2026

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kezhenxu94 approved these changes Apr 5, 2026

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kezhenxu94 merged commit 5f499dc into apache:main Apr 5, 2026
4 of 5 checks passed

ivankatliarchuk deleted the feat/support-go-mod-variants branch April 5, 2026 11:10

	possibleLicenseFileName = regexp.MustCompile(`(?i)^LICENSE\|LICENCE(\.txt)?\|COPYING(\.txt)?$`)
	possibleLicenseFileName = regexp.MustCompile(`(?i)^(LICENSE\|LICENCE\|COPYING)(\.txt)?$`)

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ivankatliarchuk commented Apr 2, 2026 •

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