fix: support comma-containing values in --docker-build-options

Change flag type from StringToString to StringArray to prevent
comma-based splitting of option values. This allows docker buildx
cache options like cache-to=type=gha,mode=max to work correctly.

Co-authored-by: Ona <no-reply@ona.com>

Author: WVerlaek

cmd/build.go

@@ -231,7 +231,7 @@ func addBuildFlags(cmd *cobra.Command) {
 	cmd.Flags().String("coverage-output-path", "", "Output path where test coverage file will be copied after running tests")
 	cmd.Flags().Bool("disable-coverage", false, "Disable test coverage collection (defaults to false)")
 	cmd.Flags().Bool("enable-test-tracing", false, "Enable per-test OpenTelemetry span creation (defaults to false)")
-	cmd.Flags().StringToString("docker-build-options", nil, "Options passed to all 'docker build' commands")
+	cmd.Flags().StringArray("docker-build-options", nil, "Options passed to all 'docker build' commands (can be repeated, e.g., --docker-build-options=cache-to=type=gha,mode=max)")
 	cmd.Flags().Bool("slsa-cache-verification", false, "Enable SLSA verification for cached artifacts")
 	cmd.Flags().String("slsa-source-uri", "", "Expected source URI for SLSA verification (required when verification enabled)")
 	cmd.Flags().Bool("slsa-require-attestation", false, "Require SLSA attestations (missing/invalid → build locally)")
@@ -367,11 +367,11 @@ func getBuildOpts(cmd *cobra.Command) ([]leeway.BuildOption, cache.LocalCache) {
 	disableCoverage, _ := cmd.Flags().GetBool("disable-coverage")
 	enableTestTracing, _ := cmd.Flags().GetBool("enable-test-tracing")
 
-	var dockerBuildOptions leeway.DockerBuildOptions
-	dockerBuildOptions, err = cmd.Flags().GetStringToString("docker-build-options")
+	dockerBuildOptionsSlice, err := cmd.Flags().GetStringArray("docker-build-options")
 	if err != nil {
 		log.Fatal(err)
 	}
+	dockerBuildOptions := leeway.DockerBuildOptions(dockerBuildOptionsSlice)
 
 	jailedExecution, err := cmd.Flags().GetBool("jailed-execution")
 	if err != nil {

pkg/leeway/build.go

@@ -495,8 +495,9 @@ type buildOptions struct {
 	context *buildContext
 }
 
-// DockerBuildOptions are options passed to "docker build"
-type DockerBuildOptions map[string]string
+// DockerBuildOptions are options passed to "docker build".
+// Each entry is a "key=value" string that becomes "--key=value" in the docker command.
+type DockerBuildOptions []string
 
 // BuildOption configures the build behaviour
 type BuildOption func(*buildOptions) error
@@ -2408,8 +2409,8 @@ func (p *Package) buildDocker(buildctx *buildContext, wd, result string) (res *p
 		buildcmd = append(buildcmd, "--squash")
 	}
 	if buildctx.DockerBuildOptions != nil {
-		for opt, v := range *buildctx.DockerBuildOptions {
-			buildcmd = append(buildcmd, fmt.Sprintf("--%s=%s", opt, v))
+		for _, opt := range *buildctx.DockerBuildOptions {
+			buildcmd = append(buildcmd, fmt.Sprintf("--%s", opt))
 		}
 	}
 	buildcmd = append(buildcmd, ".")

pkg/leeway/build_internal_test.go

@@ -333,3 +333,57 @@ func TestYarnAppExtraction_ScopedPackage(t *testing.T) {
 		})
 	}
 }
+
+func TestDockerBuildOptions_CommaInValue(t *testing.T) {
+	// DockerBuildOptions should preserve comma-containing values intact.
+	// This is the fix for: https://github.com/gitpod-io/leeway/issues/XXX
+	// Previously, using StringToString flag type would split "cache-to=type=gha,mode=max"
+	// into two separate options, breaking docker buildx cache options.
+
+	tests := []struct {
+		name     string
+		opts     DockerBuildOptions
+		expected []string
+	}{
+		{
+			name:     "single option with comma in value",
+			opts:     DockerBuildOptions{"cache-to=type=gha,mode=max"},
+			expected: []string{"--cache-to=type=gha,mode=max"},
+		},
+		{
+			name:     "multiple options with commas",
+			opts:     DockerBuildOptions{"cache-to=type=gha,mode=max", "cache-from=type=gha"},
+			expected: []string{"--cache-to=type=gha,mode=max", "--cache-from=type=gha"},
+		},
+		{
+			name:     "simple option without comma",
+			opts:     DockerBuildOptions{"no-cache=true"},
+			expected: []string{"--no-cache=true"},
+		},
+		{
+			name:     "empty options",
+			opts:     DockerBuildOptions{},
+			expected: []string{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var result []string
+			for _, opt := range tt.opts {
+				result = append(result, fmt.Sprintf("--%s", opt))
+			}
+
+			if len(result) != len(tt.expected) {
+				t.Errorf("got %d options, want %d", len(result), len(tt.expected))
+				return
+			}
+
+			for i, got := range result {
+				if got != tt.expected[i] {
+					t.Errorf("option %d: got %q, want %q", i, got, tt.expected[i])
+				}
+			}
+		})
+	}
+}