fix: use correct default branch in multi-source applications (#1056)

Signed-off-by: Atif Ali <atali@redhat.com>

Author: aali309

pkg/argocd/git.go

@@ -17,6 +17,7 @@ import (
 	"sigs.k8s.io/kustomize/kyaml/order"
 	kyaml "sigs.k8s.io/kustomize/kyaml/yaml"
 
+	"github.com/argoproj-labs/argocd-image-updater/pkg/common"
 	"github.com/argoproj-labs/argocd-image-updater/registry-scanner/pkg/image"
 
 	"github.com/argoproj-labs/argocd-image-updater/ext/git"
@@ -128,6 +129,33 @@ func TemplateBranchName(branchName string, changeList []ChangeEntry) string {
 
 type changeWriter func(app *v1alpha1.Application, wbc *WriteBackConfig, gitC git.Client) (err error, skip bool)
 
+// getWriteBackBranch returns the branch to use for write-back operations.
+// It first checks for a branch specified in annotations, then uses the
+// targetRevision from the matching git source, falling back to getApplicationSource.
+func getWriteBackBranch(app *v1alpha1.Application) string {
+	if app == nil {
+		return ""
+	}
+	// If git repository is specified, find matching source
+	if gitRepo, ok := app.GetAnnotations()[common.GitRepositoryAnnotation]; ok {
+		if app.Spec.HasMultipleSources() {
+			for _, s := range app.Spec.Sources {
+				if s.RepoURL == gitRepo {
+					log.WithContext().AddField("application", app.GetName()).
+						Debugf("Using target revision '%s' from matching source '%s'", s.TargetRevision, gitRepo)
+					return s.TargetRevision
+				}
+			}
+			log.WithContext().AddField("application", app.GetName()).
+				Debugf("No matching source found for git repository %s, falling back to primary source", gitRepo)
+		}
+	}
+
+	// Fall back to getApplicationSource's targetRevision
+	// This maintains consistency with how other parts of the code select the source
+	return getApplicationSource(app).TargetRevision
+}
+
 // commitChanges commits any changes required for updating one or more images
 // after the UpdateApplication cycle has finished.
 func commitChangesGit(app *v1alpha1.Application, wbc *WriteBackConfig, changeList []ChangeEntry, write changeWriter) error {
@@ -164,9 +192,11 @@ func commitChangesGit(app *v1alpha1.Application, wbc *WriteBackConfig, changeLis
 	// config, or taken from the application spec's targetRevision. If the
 	// target revision is set to the special value HEAD, or is the empty
 	// string, we'll try to resolve it to a branch name.
-	checkOutBranch := getApplicationSource(app).TargetRevision
+	var checkOutBranch string
 	if wbc.GitBranch != "" {
 		checkOutBranch = wbc.GitBranch
+	} else {
+		checkOutBranch = getWriteBackBranch(app)
 	}
 	logCtx.Tracef("targetRevision for update is '%s'", checkOutBranch)
 	if checkOutBranch == "" || checkOutBranch == "HEAD" {

pkg/argocd/git_test.go

@@ -10,6 +10,8 @@ import (
 	"github.com/argoproj-labs/argocd-image-updater/registry-scanner/pkg/image"
 	"github.com/argoproj-labs/argocd-image-updater/registry-scanner/pkg/tag"
 
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
 	"sigs.k8s.io/kustomize/api/types"
 	kyaml "sigs.k8s.io/kustomize/kyaml/yaml"
 
@@ -329,3 +331,132 @@ func Test_updateKustomizeFile(t *testing.T) {
 		})
 	}
 }
+
+func Test_getApplicationSource(t *testing.T) {
+	t.Run("multi-source without git repo annotation", func(t *testing.T) {
+		app := &v1alpha1.Application{
+			ObjectMeta: v1.ObjectMeta{
+				Name: "test-app",
+			},
+			Spec: v1alpha1.ApplicationSpec{
+				Sources: v1alpha1.ApplicationSources{
+					{
+						RepoURL:        "https://charts.bitnami.com/bitnami",
+						TargetRevision: "18.2.3",
+						Chart:          "nginx",
+						Helm:           &v1alpha1.ApplicationSourceHelm{},
+					},
+					{
+						RepoURL:        "https://github.com/chengfang/image-updater-examples.git",
+						TargetRevision: "main",
+					},
+				},
+			},
+		}
+
+		source := getApplicationSource(app)
+		assert.Equal(t, "18.2.3", source.TargetRevision)
+		assert.Equal(t, "https://charts.bitnami.com/bitnami", source.RepoURL)
+	})
+
+	t.Run("single source application", func(t *testing.T) {
+		app := &v1alpha1.Application{
+			ObjectMeta: v1.ObjectMeta{
+				Name: "test-app",
+			},
+			Spec: v1alpha1.ApplicationSpec{
+				Source: &v1alpha1.ApplicationSource{
+					RepoURL:        "https://github.com/example/repo.git",
+					TargetRevision: "main",
+				},
+			},
+		}
+
+		source := getApplicationSource(app)
+		assert.Equal(t, "main", source.TargetRevision)
+		assert.Equal(t, "https://github.com/example/repo.git", source.RepoURL)
+	})
+}
+
+func Test_getWriteBackBranch(t *testing.T) {
+	t.Run("nil application", func(t *testing.T) {
+		branch := getWriteBackBranch(nil)
+		assert.Equal(t, "", branch)
+	})
+
+	t.Run("matching git-repository annotation", func(t *testing.T) {
+		app := &v1alpha1.Application{
+			ObjectMeta: v1.ObjectMeta{
+				Name: "test-app",
+				Annotations: map[string]string{
+					"argocd-image-updater.argoproj.io/git-repository": "https://github.com/chengfang/image-updater-examples.git",
+				},
+			},
+			Spec: v1alpha1.ApplicationSpec{
+				Sources: v1alpha1.ApplicationSources{
+					{
+						RepoURL:        "https://charts.bitnami.com/bitnami",
+						TargetRevision: "18.2.3",
+						Chart:          "nginx",
+					},
+					{
+						RepoURL:        "https://github.com/chengfang/image-updater-examples.git",
+						TargetRevision: "main",
+					},
+				},
+			},
+		}
+
+		branch := getWriteBackBranch(app)
+		assert.Equal(t, "main", branch)
+	})
+
+	t.Run("fallback to primary source when no match", func(t *testing.T) {
+		app := &v1alpha1.Application{
+			ObjectMeta: v1.ObjectMeta{
+				Name: "test-app",
+			},
+			Spec: v1alpha1.ApplicationSpec{
+				Sources: v1alpha1.ApplicationSources{
+					{
+						RepoURL:        "https://charts.bitnami.com/bitnami",
+						TargetRevision: "18.2.3",
+						Chart:          "nginx",
+						Helm:           &v1alpha1.ApplicationSourceHelm{},
+					},
+					{
+						RepoURL:        "https://github.com/chengfang/image-updater-examples.git",
+						TargetRevision: "main",
+					},
+				},
+			},
+		}
+
+		branch := getWriteBackBranch(app)
+		assert.Equal(t, "18.2.3", branch)
+	})
+
+	t.Run("git-repository annotation with non-matching URL", func(t *testing.T) {
+		app := &v1alpha1.Application{
+			ObjectMeta: v1.ObjectMeta{
+				Name: "test-app",
+				Annotations: map[string]string{
+					"argocd-image-updater.argoproj.io/git-repository": "https://github.com/different/repo.git",
+				},
+			},
+			Spec: v1alpha1.ApplicationSpec{
+				Sources: v1alpha1.ApplicationSources{
+					{
+						RepoURL:        "https://charts.bitnami.com/bitnami",
+						TargetRevision: "18.2.3",
+						Chart:          "nginx",
+						Helm:           &v1alpha1.ApplicationSourceHelm{},
+					},
+				},
+			},
+		}
+
+		branch := getWriteBackBranch(app)
+		assert.Equal(t, "18.2.3", branch)
+	})
+}