Set common labels and annotations as strings

api/filters/annotations/annotations.go

@@ -30,7 +30,7 @@ func (f Filter) Filter(nodes []*yaml.RNode) ([]*yaml.RNode, error) {
 			for _, k := range keys {
 				if err := node.PipeE(fsslice.Filter{
 					FsSlice:    f.FsSlice,
-					SetValue:   fsslice.SetEntry(k, f.Annotations[k]),
+					SetValue:   fsslice.SetEntry(k, f.Annotations[k], yaml.StringTag),
 					CreateKind: yaml.MappingNode, // Annotations are MappingNodes.
 				}); err != nil {
 					return nil, err

api/filters/annotations/annotations_test.go

@@ -123,6 +123,33 @@ a:
 				},
 			},
 		},
+
+		"number": {
+			input: `
+apiVersion: example.com/v1
+kind: Foo
+metadata:
+  name: instance
+  annotations:
+    hero: batman
+    fiend: riddler
+`,
+			expectedOutput: `
+apiVersion: example.com/v1
+kind: Foo
+metadata:
+  name: instance
+  annotations:
+    hero: batman
+    fiend: riddler
+    2: ford
+    clown: "1"
+`,
+			filter: Filter{Annotations: annoMap{
+				"clown": "1",
+				"2":     "ford",
+			}},
+		},
 	}
 
 	for tn, tc := range testCases {