fix: elements should be optional (argoproj#17424)

A bug was reported, where an applicationset with an empty elements
array, when created with `argocd appset create <filename>.yaml` gets a
`...list.elements: Required value` error.

My hypothesis is that when calling the K8s API, golang JSON marshalling
mangles the empty `elements` array to `nil`, rather than creating an
empty array when submitting the `POST`.

Still need to figure out why the same setup seemingly works fine when
the same appset is in an app-of-apps.

Signed-off-by: Blake Pettersson <blake.pettersson@gmail.com>

assets/swagger.json

@@ -7413,6 +7413,7 @@
       "properties": {
         "elements": {
           "type": "array",
+          "title": "+kubebuilder:validation:Optional",
           "items": {
             "$ref": "#/definitions/v1JSON"
           }

manifests/core-install.yaml

@@ -7394,8 +7394,6 @@ spec:
                           - metadata
                           - spec
                           type: object
-                      required:
-                      - elements
                       type: object
                     matrix:
                       properties:
@@ -9754,8 +9752,6 @@ spec:
                                     - metadata
                                     - spec
                                     type: object
-                                required:
-                                - elements
                                 type: object
                               matrix:
                                 x-kubernetes-preserve-unknown-fields: true
@@ -14813,8 +14809,6 @@ spec:
                                     - metadata
                                     - spec
                                     type: object
-                                required:
-                                - elements
                                 type: object
                               matrix:
                                 x-kubernetes-preserve-unknown-fields: true

manifests/crds/applicationset-crd.yaml

@@ -2386,8 +2386,6 @@ spec:
                           - metadata
                           - spec
                           type: object
-                      required:
-                      - elements
                       type: object
                     matrix:
                       properties:
@@ -4746,8 +4744,6 @@ spec:
                                     - metadata
                                     - spec
                                     type: object
-                                required:
-                                - elements
                                 type: object
                               matrix:
                                 x-kubernetes-preserve-unknown-fields: true
@@ -9805,8 +9801,6 @@ spec:
                                     - metadata
                                     - spec
                                     type: object
-                                required:
-                                - elements
                                 type: object
                               matrix:
                                 x-kubernetes-preserve-unknown-fields: true

manifests/ha/install.yaml

@@ -7394,8 +7394,6 @@ spec:
                           - metadata
                           - spec
                           type: object
-                      required:
-                      - elements
                       type: object
                     matrix:
                       properties:
@@ -9754,8 +9752,6 @@ spec:
                                     - metadata
                                     - spec
                                     type: object
-                                required:
-                                - elements
                                 type: object
                               matrix:
                                 x-kubernetes-preserve-unknown-fields: true
@@ -14813,8 +14809,6 @@ spec:
                                     - metadata
                                     - spec
                                     type: object
-                                required:
-                                - elements
                                 type: object
                               matrix:
                                 x-kubernetes-preserve-unknown-fields: true

manifests/install.yaml

@@ -7394,8 +7394,6 @@ spec:
                           - metadata
                           - spec
                           type: object
-                      required:
-                      - elements
                       type: object
                     matrix:
                       properties:
@@ -9754,8 +9752,6 @@ spec:
                                     - metadata
                                     - spec
                                     type: object
-                                required:
-                                - elements
                                 type: object
                               matrix:
                                 x-kubernetes-preserve-unknown-fields: true
@@ -14813,8 +14809,6 @@ spec:
                                     - metadata
                                     - spec
                                     type: object
-                                required:
-                                - elements
                                 type: object
                               matrix:
                                 x-kubernetes-preserve-unknown-fields: true

pkg/apis/application/v1alpha1/applicationset_types.go

@@ -260,6 +260,7 @@ func (g ApplicationSetTerminalGenerators) toApplicationSetNestedGenerators() []A
 
 // ListGenerator include items info
 type ListGenerator struct {
+	// +kubebuilder:validation:Optional
 	Elements     []apiextensionsv1.JSON `json:"elements" protobuf:"bytes,1,name=elements"`
 	Template     ApplicationSetTemplate `json:"template,omitempty" protobuf:"bytes,2,name=template"`
 	ElementsYaml string                 `json:"elementsYaml,omitempty" protobuf:"bytes,3,opt,name=elementsYaml"`