// patchResource divides PatchResource for easier unit testing
func patchResource(ctx api.Context, timeout time.Duration, versionedObj runtime.Object, patcher rest.Patcher, name string, patchType api.PatchType, patchJS []byte, namer ScopeNamer, codec runtime.Codec) (runtime.Object, error) {
namespace := api.NamespaceValue(ctx)
original, err := patcher.Get(ctx, name)
if err != nil {
return nil, err
}
originalObjJS, err := codec.Encode(original)
if err != nil {
return nil, err
}
originalPatchedObjJS, err := getPatchedJS(patchType, originalObjJS, patchJS, versionedObj)
if err != nil {
return nil, err
}
objToUpdate := patcher.New()
if err := codec.DecodeInto(originalPatchedObjJS, objToUpdate); err != nil {
return nil, err
}
if err := checkName(objToUpdate, name, namespace, namer); err != nil {
return nil, err
}
return finishRequest(timeout, func() (runtime.Object, error) {
// update should never create as previous get would fail
updateObject, _, updateErr := patcher.Update(ctx, objToUpdate)
for i := 0; i < MaxPatchConflicts && (errors.IsConflict(updateErr)); i++ {
// on a conflict,
// 1. build a strategic merge patch from originalJS and the patchedJS. Different patch types can
// be specified, but a strategic merge patch should be expressive enough handle them. Build the
// patch with this type to handle those cases.
// 2. build a strategic merge patch from originalJS and the currentJS
// 3. ensure no conflicts between the two patches
// 4. apply the #1 patch to the currentJS object
// 5. retry the update
currentObject, err := patcher.Get(ctx, name)
if err != nil {
return nil, err
}
currentObjectJS, err := codec.Encode(currentObject)
if err != nil {
return nil, err
}
currentPatch, err := strategicpatch.CreateStrategicMergePatch(originalObjJS, currentObjectJS, patcher.New())
if err != nil {
return nil, err
}
originalPatch, err := strategicpatch.CreateStrategicMergePatch(originalObjJS, originalPatchedObjJS, patcher.New())
if err != nil {
return nil, err
}
diff1 := make(map[string]interface{})
if err := json.Unmarshal(originalPatch, &diff1); err != nil {
return nil, err
}
diff2 := make(map[string]interface{})
if err := json.Unmarshal(currentPatch, &diff2); err != nil {
return nil, err
}
hasConflicts, err := strategicpatch.HasConflicts(diff1, diff2)
if err != nil {
return nil, err
}
if hasConflicts {
return updateObject, updateErr
}
newlyPatchedObjJS, err := getPatchedJS(api.StrategicMergePatchType, currentObjectJS, originalPatch, versionedObj)
if err != nil {
return nil, err
}
if err := codec.DecodeInto(newlyPatchedObjJS, objToUpdate); err != nil {
return nil, err
}
updateObject, _, updateErr = patcher.Update(ctx, objToUpdate)
}
return updateObject, updateErr
})
}
// PatchResource returns a function that will handle a resource patch
// TODO: Eventually PatchResource should just use GuaranteedUpdate and this routine should be a bit cleaner
func PatchResource(r rest.Patcher, scope RequestScope, typer runtime.ObjectTyper, admit admission.Interface, converter runtime.ObjectConvertor) restful.RouteFunction {
return func(req *restful.Request, res *restful.Response) {
w := res.ResponseWriter
// TODO: we either want to remove timeout or document it (if we
// document, move timeout out of this function and declare it in
// api_installer)
timeout := parseTimeout(req.Request.URL.Query().Get("timeout"))
namespace, name, err := scope.Namer.Name(req)
if err != nil {
errorJSON(err, scope.Codec, w)
return
}
obj := r.New()
ctx := scope.ContextFunc(req)
ctx = api.WithNamespace(ctx, namespace)
// PATCH requires same permission as UPDATE
if admit.Handles(admission.Update) {
userInfo, _ := api.UserFrom(ctx)
err = admit.Admit(admission.NewAttributesRecord(obj, scope.Kind, namespace, name, scope.Resource, scope.Subresource, admission.Update, userInfo))
if err != nil {
errorJSON(err, scope.Codec, w)
return
}
}
versionedObj, err := converter.ConvertToVersion(obj, scope.APIVersion)
if err != nil {
errorJSON(err, scope.Codec, w)
return
}
original, err := r.Get(ctx, name)
if err != nil {
errorJSON(err, scope.Codec, w)
return
}
originalObjJS, err := scope.Codec.Encode(original)
if err != nil {
errorJSON(err, scope.Codec, w)
return
}
patchJS, err := readBody(req.Request)
if err != nil {
errorJSON(err, scope.Codec, w)
return
}
contentType := req.HeaderParameter("Content-Type")
patchedObjJS, err := getPatchedJS(contentType, originalObjJS, patchJS, versionedObj)
if err != nil {
errorJSON(err, scope.Codec, w)
return
}
if err := scope.Codec.DecodeInto(patchedObjJS, obj); err != nil {
errorJSON(err, scope.Codec, w)
return
}
if err := checkName(obj, name, namespace, scope.Namer); err != nil {
errorJSON(err, scope.Codec, w)
return
}
result, err := finishRequest(timeout, func() (runtime.Object, error) {
// update should never create as previous get would fail
obj, _, err := r.Update(ctx, obj)
return obj, err
})
if err != nil {
errorJSON(err, scope.Codec, w)
return
}
if err := setSelfLink(result, req, scope.Namer); err != nil {
errorJSON(err, scope.Codec, w)
return
}
write(http.StatusOK, scope.APIVersion, scope.Codec, result, w, req.Request)
}
}