Add annotation to disable decryption on a per object basis

docs/spec/v1/kustomizations.md

@@ -1264,6 +1264,18 @@ data:
   sops.vault-token: <BASE64>
 ```
 
+#### Controlling the decryption behavior of resources
+
+To change the decryption behaviour for specific Kubernetes resources, you can annotate them with:
+
+| Annotation                          | Default    | Values                                                         | Role            |
+|-------------------------------------|------------|----------------------------------------------------------------|-----------------|
+| `kustomize.toolkit.fluxcd.io/decrypt` | `Enabled` | - `Enabled`<br/>- `Disabled`                                   | Decryption policy |
+
+##### Disabled
+
+The `Disabled` policy instructs the controller to not decrypt Kubernetes resources. This might be useful if there is another entity that is going to decrpyt the resource later.
+
 ## Working with Kustomizations
 
 ### Recommended settings

internal/controller/kustomization_controller.go

@@ -890,7 +890,7 @@ func (r *KustomizationReconciler) apply(ctx context.Context,
 	}
 
 	for _, u := range objects {
-		if decryptor.IsEncryptedSecret(u) {
+		if decryptor.IsEncryptedSecret(u) && !decryptor.IsDecryptionDisabled(u.GetAnnotations()) {
 			return false, nil,
 				fmt.Errorf("%s is SOPS encrypted, configuring decryption is required for this secret to be reconciled",
 					ssautil.FmtUnstructured(u))

internal/decryptor/decryptor.go

@@ -187,6 +187,12 @@ func New(client client.Client, kustomization *kustomizev1.Kustomization, opts ..
 	return d, cleanup, nil
 }
 
+// IsDecryptionDisabled checks if the given object has the decrypt: disabled annotation set
+func IsDecryptionDisabled(annotations map[string]string) bool {
+	return annotations != nil &&
+		strings.EqualFold(annotations[fmt.Sprintf("%s/decrypt", kustomizev1.GroupVersion.Group)], kustomizev1.DisabledValue)
+}
+
 // IsEncryptedSecret checks if the given object is a Kubernetes Secret encrypted
 // with Mozilla SOPS.
 func IsEncryptedSecret(object *unstructured.Unstructured) bool {
@@ -436,7 +442,10 @@ func (d *Decryptor) SopsDecryptWithFormat(data []byte, inputFormat, outputFormat
 // while decrypting with DecryptionProviderSOPS, to allow individual data entries
 // injected by e.g. a Kustomize secret generator to be decrypted
 func (d *Decryptor) DecryptResource(res *resource.Resource) (*resource.Resource, error) {
-	if res == nil || d.kustomization.Spec.Decryption == nil || d.kustomization.Spec.Decryption.Provider == "" {
+	if res == nil ||
+		d.kustomization.Spec.Decryption == nil ||
+		d.kustomization.Spec.Decryption.Provider == "" ||
+		IsDecryptionDisabled(res.GetAnnotations()) {
 		return nil, nil
 	}
 

internal/decryptor/decryptor_test.go

@@ -632,8 +632,18 @@ func TestDecryptor_DecryptResource(t *testing.T) {
 		g.Expect(secret.UnmarshalJSON(encData)).To(Succeed())
 		g.Expect(isSOPSEncryptedResource(secret)).To(BeTrue())
 
+		secret.SetAnnotations(map[string]string{
+			"kustomize.toolkit.fluxcd.io/decrypt": "disabled",
+		})
+
 		got, err := d.DecryptResource(secret)
 		g.Expect(err).ToNot(HaveOccurred())
+		g.Expect(got).To(BeNil())
+
+		secret.SetAnnotations(map[string]string{})
+
+		got, err = d.DecryptResource(secret)
+		g.Expect(err).ToNot(HaveOccurred())
 		g.Expect(got).ToNot(BeNil())
 		g.Expect(got.MarshalJSON()).To(Equal(secretData))
 	})