// patchResource divides PatchResource for easier unit testing
func patchResource(
ctx api.Context,
admit updateAdmissionFunc,
timeout time.Duration,
versionedObj runtime.Object,
patcher rest.Patcher,
name string,
patchType api.PatchType,
patchJS []byte,
namer ScopeNamer,
copier runtime.ObjectCopier,
resource unversioned.GroupVersionResource,
codec runtime.Codec,
) (runtime.Object, error) {
namespace := api.NamespaceValue(ctx)
var (
originalObjJS []byte
originalPatchedObjJS []byte
lastConflictErr error
)
// applyPatch is called every time GuaranteedUpdate asks for the updated object,
// and is given the currently persisted object as input.
applyPatch := func(_ api.Context, _, currentObject runtime.Object) (runtime.Object, error) {
// Make sure we actually have a persisted currentObject
if hasUID, err := hasUID(currentObject); err != nil {
return nil, err
} else if !hasUID {
return nil, errors.NewNotFound(resource.GroupResource(), name)
}
switch {
case len(originalObjJS) == 0 || len(originalPatchedObjJS) == 0:
// first time through,
// 1. apply the patch
// 2. save the originalJS and patchedJS to detect whether there were conflicting changes on retries
if js, err := runtime.Encode(codec, currentObject); err != nil {
return nil, err
} else {
originalObjJS = js
}
if js, err := getPatchedJS(patchType, originalObjJS, patchJS, versionedObj); err != nil {
return nil, err
} else {
originalPatchedObjJS = js
}
objToUpdate := patcher.New()
if err := runtime.DecodeInto(codec, originalPatchedObjJS, objToUpdate); err != nil {
return nil, err
}
if err := checkName(objToUpdate, name, namespace, namer); err != nil {
return nil, err
}
return objToUpdate, nil
default:
// 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
currentObjectJS, err := runtime.Encode(codec, currentObject)
if err != nil {
return nil, err
}
currentPatch, err := strategicpatch.CreateStrategicMergePatch(originalObjJS, currentObjectJS, versionedObj)
if err != nil {
return nil, err
}
originalPatch, err := strategicpatch.CreateStrategicMergePatch(originalObjJS, originalPatchedObjJS, versionedObj)
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 {
glog.V(4).Infof("patchResource failed for resource %s, because there is a meaningful conflict.\n diff1=%v\n, diff2=%v\n", name, diff1, diff2)
// Return the last conflict error we got if we have one
if lastConflictErr != nil {
return nil, lastConflictErr
}
// Otherwise manufacture one of our own
return nil, errors.NewConflict(resource.GroupResource(), name, nil)
}
newlyPatchedObjJS, err := getPatchedJS(api.StrategicMergePatchType, currentObjectJS, originalPatch, versionedObj)
if err != nil {
return nil, err
}
objToUpdate := patcher.New()
if err := runtime.DecodeInto(codec, newlyPatchedObjJS, objToUpdate); err != nil {
return nil, err
}
return objToUpdate, nil
}
}
// applyAdmission is called every time GuaranteedUpdate asks for the updated object,
// and is given the currently persisted object and the patched object as input.
applyAdmission := func(ctx api.Context, patchedObject runtime.Object, currentObject runtime.Object) (runtime.Object, error) {
return patchedObject, admit(patchedObject, currentObject)
}
updatedObjectInfo := rest.DefaultUpdatedObjectInfo(nil, copier, applyPatch, applyAdmission)
return finishRequest(timeout, func() (runtime.Object, error) {
updateObject, _, updateErr := patcher.Update(ctx, name, updatedObjectInfo)
for i := 0; i < MaxPatchConflicts && (errors.IsConflict(updateErr)); i++ {
lastConflictErr = updateErr
updateObject, _, updateErr = patcher.Update(ctx, name, updatedObjectInfo)
}
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 {
scope.err(err, res.ResponseWriter, req.Request)
return
}
ctx := scope.ContextFunc(req)
ctx = api.WithNamespace(ctx, namespace)
versionedObj, err := converter.ConvertToVersion(r.New(), scope.Kind.GroupVersion())
if err != nil {
scope.err(err, res.ResponseWriter, req.Request)
return
}
// TODO: handle this in negotiation
contentType := req.HeaderParameter("Content-Type")
// Remove "; charset=" if included in header.
if idx := strings.Index(contentType, ";"); idx > 0 {
contentType = contentType[:idx]
}
patchType := api.PatchType(contentType)
patchJS, err := readBody(req.Request)
if err != nil {
scope.err(err, res.ResponseWriter, req.Request)
return
}
s, ok := scope.Serializer.SerializerForMediaType("application/json", nil)
if !ok {
scope.err(fmt.Errorf("no serializer defined for JSON"), res.ResponseWriter, req.Request)
return
}
gv := scope.Kind.GroupVersion()
codec := runtime.NewCodec(
scope.Serializer.EncoderForVersion(s, gv),
scope.Serializer.DecoderToVersion(s, unversioned.GroupVersion{Group: gv.Group, Version: runtime.APIVersionInternal}),
)
updateAdmit := func(updatedObject runtime.Object, currentObject runtime.Object) error {
if admit != nil && admit.Handles(admission.Update) {
userInfo, _ := api.UserFrom(ctx)
return admit.Admit(admission.NewAttributesRecord(updatedObject, currentObject, scope.Kind, namespace, name, scope.Resource, scope.Subresource, admission.Update, userInfo))
}
return nil
}
result, err := patchResource(ctx, updateAdmit, timeout, versionedObj, r, name, patchType, patchJS, scope.Namer, scope.Copier, scope.Resource, codec)
if err != nil {
scope.err(err, res.ResponseWriter, req.Request)
return
}
if err := setSelfLink(result, req, scope.Namer); err != nil {
scope.err(err, res.ResponseWriter, req.Request)
return
}
write(http.StatusOK, scope.Kind.GroupVersion(), scope.Serializer, result, w, req.Request)
}
}