Add support for JSON 6902 style patching (#202)

docs/examples/modifying_resources.md

@@ -52,6 +52,38 @@ await pod.label({"foo": "bar"})
 
 `````
 
+## Replace all Pod labels
+
+Using the JSON 6902 style patching replace all Pod labels with `{"patched": "true"}`.
+
+`````{tab-set}
+
+````{tab-item} Sync
+```python
+from kr8s.objects import Pod
+
+pod = Pod("my-pod", namespace="kube-system")
+pod.patch(
+    [{"op": "replace", "path": "/metadata/labels", "value": {"patched": "true"}}],
+    type="json",
+)
+```
+````
+
+````{tab-item} Async
+```python
+from kr8s.asyncio.objects import Pod
+
+pod = await Pod("my-pod", namespace="kube-system")
+await pod.patch(
+    [{"op": "replace", "path": "/metadata/labels", "value": {"patched": "true"}}],
+    type="json",
+)
+```
+````
+
+`````
+
 ## Cordon a Node
 
 Cordon a Node to mark it as unschedulable.

kr8s/_objects.py

@@ -281,13 +281,17 @@ async def _refresh(self) -> None:
                 raise NotFoundError(f"Object {self.name} does not exist") from e
             raise e
 
-    async def patch(self, patch, *, subresource=None) -> None:
+    async def patch(self, patch, *, subresource=None, type=None) -> None:
         """Patch this object in Kubernetes."""
-        await self._patch(patch, subresource=subresource)
+        await self._patch(patch, subresource=subresource, type=type)
 
-    async def _patch(self, patch: Dict, *, subresource=None) -> None:
+    async def _patch(self, patch: Dict, *, subresource=None, type=None) -> None:
         """Patch this object in Kubernetes."""
         url = f"{self.endpoint}/{self.name}"
+        if type == "json":
+            headers = {"Content-Type": "application/json-patch+json"}
+        else:
+            headers = {"Content-Type": "application/merge-patch+json"}
         if subresource:
             url = f"{url}/{subresource}"
         try:
@@ -297,7 +301,7 @@ async def _patch(self, patch: Dict, *, subresource=None) -> None:
                 url=url,
                 namespace=self.namespace,
                 data=json.dumps(patch),
-                headers={"Content-Type": "application/merge-patch+json"},
+                headers=headers,
             ) as resp:
                 self.raw = resp.json()
         except httpx.HTTPStatusError as e:

kr8s/tests/test_objects.py

@@ -368,6 +368,18 @@ async def test_patch_pod(example_pod_spec):
     await pod.delete()
 
 
+async def test_patch_pod_json(example_pod_spec):
+    pod = await Pod(example_pod_spec)
+    await pod.create()
+    assert "patched" not in pod.labels
+    await pod.patch(
+        [{"op": "replace", "path": "/metadata/labels", "value": {"patched": "true"}}],
+        type="json",
+    )
+    assert set(pod.labels) == {"patched"}
+    await pod.delete()
+
+
 async def test_all_v1_objects_represented():
     kubernetes = await kr8s.asyncio.api()
     k8s_objects = await kubernetes.api_resources()