From 74356e8d08c0ee87ca2045e1d8c795317bf62aca Mon Sep 17 00:00:00 2001
From: Radek Simko <radek.simko@gmail.com>
Date: Thu, 3 Aug 2017 17:02:55 +0200
Subject: [PATCH] Escape '/' in JSON Patch path correctly

---
 kubernetes/patch_operations.go      | 16 ++++++++---
 kubernetes/patch_operations_test.go | 42 +++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/kubernetes/patch_operations.go b/kubernetes/patch_operations.go
index e794a1324e..ea552105fe 100644
--- a/kubernetes/patch_operations.go
+++ b/kubernetes/patch_operations.go
@@ -21,7 +21,9 @@ func diffStringMap(pathPrefix string, oldV, newV map[string]interface{}) PatchOp
 		if _, ok := newV[k]; ok {
 			continue
 		}
-		ops = append(ops, &RemoveOperation{Path: pathPrefix + "/" + k})
+		ops = append(ops, &RemoveOperation{
+			Path: pathPrefix + "/" + escapeJsonPointer(k),
+		})
 	}
 
 	for k, v := range newV {
@@ -33,14 +35,14 @@ func diffStringMap(pathPrefix string, oldV, newV map[string]interface{}) PatchOp
 			}
 
 			ops = append(ops, &ReplaceOperation{
-				Path:  pathPrefix + "/" + k,
+				Path:  pathPrefix + "/" + escapeJsonPointer(k),
 				Value: newValue,
 			})
 			continue
 		}
 
 		ops = append(ops, &AddOperation{
-			Path:  pathPrefix + "/" + k,
+			Path:  pathPrefix + "/" + escapeJsonPointer(k),
 			Value: newValue,
 		})
 	}
@@ -48,6 +50,14 @@ func diffStringMap(pathPrefix string, oldV, newV map[string]interface{}) PatchOp
 	return ops
 }
 
+// escapeJsonPointer escapes string per RFC 6901
+// so it can be used as path in JSON patch operations
+func escapeJsonPointer(path string) string {
+	path = strings.Replace(path, "~", "~0", -1)
+	path = strings.Replace(path, "/", "~1", -1)
+	return path
+}
+
 type PatchOperations []PatchOperation
 
 func (po PatchOperations) MarshalJSON() ([]byte, error) {
diff --git a/kubernetes/patch_operations_test.go b/kubernetes/patch_operations_test.go
index c60a5e628c..523579ac01 100644
--- a/kubernetes/patch_operations_test.go
+++ b/kubernetes/patch_operations_test.go
@@ -112,6 +112,30 @@ func TestDiffStringMap(t *testing.T) {
 				},
 			},
 		},
+		{
+			Path: "/parent/",
+			Old: map[string]interface{}{
+				"two~with-tilde":           "220",
+				"three/with/three/slashes": "330",
+			},
+			New: map[string]interface{}{
+				"one/with-slash":           "111",
+				"three/with/three/slashes": "333",
+			},
+			ExpectedOps: []PatchOperation{
+				&AddOperation{
+					Path:  "/parent/one~1with-slash",
+					Value: "111",
+				},
+				&RemoveOperation{
+					Path: "/parent/two~0with-tilde",
+				},
+				&ReplaceOperation{
+					Path:  "/parent/three~1with~1three~1slashes",
+					Value: "333",
+				},
+			},
+		},
 	}
 
 	for i, tc := range testCases {
@@ -122,5 +146,23 @@ func TestDiffStringMap(t *testing.T) {
 			}
 		})
 	}
+}
 
+func TestEscapeJsonPointer(t *testing.T) {
+	testCases := []struct {
+		Input          string
+		ExpectedOutput string
+	}{
+		{"simple", "simple"},
+		{"special-chars,but no escaping", "special-chars,but no escaping"},
+		{"escape-this/forward-slash", "escape-this~1forward-slash"},
+		{"escape-this~tilde", "escape-this~0tilde"},
+	}
+	for _, tc := range testCases {
+		output := escapeJsonPointer(tc.Input)
+		if output != tc.ExpectedOutput {
+			t.Fatalf("Expected %q as after escaping %q, given: %q",
+				tc.ExpectedOutput, tc.Input, output)
+		}
+	}
 }