Merge pull request #63414 from roycaihw/fix-delete-query

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Add conversion to properly parse query parameter propagationPolicy

**What this PR does / why we need it**:
This delete request query parameter has been broken for a year. I'm not sure if we want to deprecate the non-standard DeleteOptions body on delete request eventually. 

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #43329

**Special notes for your reviewer**:

**Release note**:

```release-note
API server properly parses propagationPolicy as a query parameter sent with a delete request
```

/sig api-machinery

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/conversion.go

@@ -75,6 +75,8 @@ func AddConversionFuncs(scheme *runtime.Scheme) error {
 		Convert_unversioned_LabelSelector_to_map,
 
 		Convert_Slice_string_To_Slice_int32,
+
+		Convert_Slice_string_To_v1_DeletionPropagation,
 	)
 }
 
@@ -304,3 +306,13 @@ func Convert_Slice_string_To_Slice_int32(in *[]string, out *[]int32, s conversio
 	}
 	return nil
 }
+
+// Convert_Slice_string_To_v1_DeletionPropagation allows converting a URL query parameter propagationPolicy
+func Convert_Slice_string_To_v1_DeletionPropagation(input *[]string, out *DeletionPropagation, s conversion.Scope) error {
+	if len(*input) > 0 {
+		*out = DeletionPropagation((*input)[0])
+	} else {
+		*out = ""
+	}
+	return nil
+}

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/conversion_test.go

@@ -47,3 +47,38 @@ func TestMapToLabelSelectorRoundTrip(t *testing.T) {
 		}
 	}
 }
+
+func TestConvertSliceStringToDeletionPropagation(t *testing.T) {
+	tcs := []struct {
+		Input  []string
+		Output v1.DeletionPropagation
+	}{
+		{
+			Input:  nil,
+			Output: "",
+		},
+		{
+			Input:  []string{},
+			Output: "",
+		},
+		{
+			Input:  []string{"foo"},
+			Output: "foo",
+		},
+		{
+			Input:  []string{"bar", "foo"},
+			Output: "bar",
+		},
+	}
+
+	for _, tc := range tcs {
+		var dp v1.DeletionPropagation
+		if err := v1.Convert_Slice_string_To_v1_DeletionPropagation(&tc.Input, &dp, nil); err != nil {
+			t.Errorf("Convert_Slice_string_To_v1_DeletionPropagation(%#v): %v", tc.Input, err)
+			continue
+		}
+		if !apiequality.Semantic.DeepEqual(dp, tc.Output) {
+			t.Errorf("slice string to DeletionPropagation conversion failed: got %v; want %v", dp, tc.Output)
+		}
+	}
+}