Add git provenance labels

as per #1290

Signed-off-by: Christian Dupuis <cd@atomist.com>

build/git_test.go

@@ -0,0 +1,115 @@
+package build
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/stretchr/testify/assert"
+)
+
+var repoDir string
+
+func setupTest(tb testing.TB) func(tb testing.TB) {
+	repoDir = tb.TempDir()
+	// required for local testing on mac to avoid strange /private symlinks
+	if runtime.GOOS == "darwin" {
+		repoDir, _ = filepath.EvalSymlinks(repoDir)
+	}
+	cmd := exec.Command("git", "init")
+	cmd.Dir = repoDir
+	err := cmd.Run()
+	assert.Nilf(tb, err, "failed to init git repo: %v", err)
+
+	df := []byte("FROM alpine:latest\n")
+	err = os.WriteFile(filepath.Join(repoDir, "Dockerfile"), df, 0644)
+	assert.Nilf(tb, err, "failed to write file: %v", err)
+
+	cmd = exec.Command("git", "add", "Dockerfile")
+	cmd.Dir = repoDir
+	err = cmd.Run()
+	assert.Nilf(tb, err, "failed to add file: %v", err)
+
+	cmd = exec.Command("git", "config", "user.name", "buildx")
+	cmd.Dir = repoDir
+	err = cmd.Run()
+	assert.Nilf(tb, err, "failed to set git user.name: %v", err)
+
+	cmd = exec.Command("git", "config", "user.email", "buildx@docker.com")
+	cmd.Dir = repoDir
+	err = cmd.Run()
+	assert.Nilf(tb, err, "failed to set git user.email: %v", err)
+
+	cmd = exec.Command("git", "commit", "-m", "Initial commit")
+	cmd.Dir = repoDir
+	err = cmd.Run()
+	assert.Nilf(tb, err, "failed to commit: %v", err)
+
+	return func(tb testing.TB) {
+		os.Unsetenv("BUILDX_GIT_LABELS")
+		os.RemoveAll(repoDir)
+	}
+}
+
+func TestAddGitProvenanceDataWithoutEnv(t *testing.T) {
+	defer setupTest(t)(t)
+	labels, err := addGitProvenance(context.Background(), repoDir, filepath.Join(repoDir, "Dockerfile"))
+	assert.Nilf(t, err, "No error expected")
+	assert.Nilf(t, labels, "No labels expected")
+}
+
+func TestAddGitProvenanceDataWithoutLabels(t *testing.T) {
+	defer setupTest(t)(t)
+	os.Setenv("BUILDX_GIT_LABELS", "full")
+	labels, err := addGitProvenance(context.Background(), repoDir, filepath.Join(repoDir, "Dockerfile"))
+	assert.Nilf(t, err, "No error expected")
+	assert.Equal(t, 2, len(labels), "Exactly 2 git provenance labels expected")
+	assert.Equal(t, "Dockerfile", labels[DockerfileLabel], "Expected a dockerfile path provenance label")
+
+	cmd := exec.Command("git", "rev-parse", "HEAD")
+	cmd.Dir = repoDir
+	out, _ := cmd.Output()
+	assert.Equal(t, strings.TrimSpace(string(out)), labels[ocispecs.AnnotationRevision], "Expected a sha provenance label")
+}
+
+func TestAddGitProvenanceDataWithLabels(t *testing.T) {
+	defer setupTest(t)(t)
+	// make a change to test dirty flag
+	df := []byte("FROM alpine:edge\n")
+	os.Mkdir(filepath.Join(repoDir, "dir"), 0755)
+	os.WriteFile(filepath.Join(repoDir, "dir", "Dockerfile"), df, 0644)
+	// add a remote
+	cmd := exec.Command("git", "remote", "add", "origin", "git@github.com:docker/buildx.git")
+	cmd.Dir = repoDir
+	cmd.Run()
+
+	os.Setenv("BUILDX_GIT_LABELS", "full")
+	labels, err := addGitProvenance(context.Background(), repoDir, filepath.Join(repoDir, "Dockerfile"))
+	assert.Nilf(t, err, "No error expected")
+	assert.Equal(t, 3, len(labels), "Exactly 3 git provenance labels expected")
+	assert.Equal(t, "Dockerfile", labels[DockerfileLabel], "Expected a dockerfile path provenance label")
+	assert.Equal(t, "git@github.com:docker/buildx.git", labels[ocispecs.AnnotationSource], "Expected a remote provenance label")
+
+	cmd = exec.Command("git", "rev-parse", "HEAD")
+	cmd.Dir = repoDir
+	out, _ := cmd.Output()
+	assert.Equal(t, fmt.Sprintf("%s-dirty", strings.TrimSpace(string(out))), labels[ocispecs.AnnotationRevision], "Expected a sha provenance label")
+}
+
+func TestAddGitProvenanceDataOutsideOfGitRepository(t *testing.T) {
+	defer setupTest(t)(t)
+	os.Setenv("BUILDX_GIT_LABELS", "full")
+	parentDir := filepath.Dir(repoDir)
+	cwd, _ := os.Getwd()
+	os.Chdir(parentDir)
+	labels, err := addGitProvenance(context.Background(), filepath.Base(repoDir), "")
+	assert.Nilf(t, err, "No error expected")
+	assert.Equal(t, "Dockerfile", labels[DockerfileLabel], "Expected a dockerfile path provenance label")
+	os.Chdir(cwd)
+}