Example #1
0
// patchResource divides PatchResource for easier unit testing
func patchResource(
	ctx request.Context,
	admit updateAdmissionFunc,
	timeout time.Duration,
	versionedObj runtime.Object,
	patcher rest.Patcher,
	name string,
	patchType types.PatchType,
	patchJS []byte,
	namer ScopeNamer,
	copier runtime.ObjectCopier,
	resource schema.GroupVersionResource,
	codec runtime.Codec,
) (runtime.Object, error) {

	namespace := request.NamespaceValue(ctx)

	var (
		originalObjJS        []byte
		originalPatchedObjJS []byte
		originalObjMap       map[string]interface{}
		originalPatchMap     map[string]interface{}
		lastConflictErr      error
	)

	// applyPatch is called every time GuaranteedUpdate asks for the updated object,
	// and is given the currently persisted object as input.
	applyPatch := func(_ request.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 originalObjJS == nil && originalObjMap == nil:
			// first time through,
			// 1. apply the patch
			// 2. save the original and patched to detect whether there were conflicting changes on retries

			objToUpdate := patcher.New()

			// For performance reasons, in case of strategicpatch, we avoid json
			// marshaling and unmarshaling and operate just on map[string]interface{}.
			// In case of other patch types, we still have to operate on JSON
			// representations.
			switch patchType {
			case types.JSONPatchType, types.MergePatchType:
				originalJS, patchedJS, err := patchObjectJSON(patchType, codec, currentObject, patchJS, objToUpdate, versionedObj)
				if err != nil {
					return nil, err
				}
				originalObjJS, originalPatchedObjJS = originalJS, patchedJS
			case types.StrategicMergePatchType:
				originalMap, patchMap, err := strategicPatchObject(codec, currentObject, patchJS, objToUpdate, versionedObj)
				if err != nil {
					return nil, err
				}
				originalObjMap, originalPatchMap = originalMap, patchMap
			}
			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

			// TODO: This should be one-step conversion that doesn't require
			// json marshaling and unmarshaling once #39017 is fixed.
			data, err := runtime.Encode(codec, currentObject)
			if err != nil {
				return nil, err
			}
			currentObjMap := make(map[string]interface{})
			if err := json.Unmarshal(data, &currentObjMap); err != nil {
				return nil, err
			}

			var currentPatchMap map[string]interface{}
			if originalObjMap != nil {
				var err error
				currentPatchMap, err = strategicpatch.CreateTwoWayMergeMapPatch(originalObjMap, currentObjMap, versionedObj)
				if err != nil {
					return nil, err
				}
			} else {
				if originalPatchMap == nil {
					// Compute original patch, if we already didn't do this in previous retries.
					originalPatch, err := strategicpatch.CreateTwoWayMergePatch(originalObjJS, originalPatchedObjJS, versionedObj)
					if err != nil {
						return nil, err
					}
					originalPatchMap = make(map[string]interface{})
					if err := json.Unmarshal(originalPatch, &originalPatchMap); err != nil {
						return nil, err
					}
				}
				// Compute current patch.
				currentObjJS, err := runtime.Encode(codec, currentObject)
				if err != nil {
					return nil, err
				}
				currentPatch, err := strategicpatch.CreateTwoWayMergePatch(originalObjJS, currentObjJS, versionedObj)
				if err != nil {
					return nil, err
				}
				currentPatchMap = make(map[string]interface{})
				if err := json.Unmarshal(currentPatch, &currentPatchMap); err != nil {
					return nil, err
				}
			}

			hasConflicts, err := strategicpatch.HasConflicts(originalPatchMap, currentPatchMap)
			if err != nil {
				return nil, err
			}
			if hasConflicts {
				if glog.V(4) {
					diff1, _ := json.Marshal(currentPatchMap)
					diff2, _ := json.Marshal(originalPatchMap)
					glog.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)
			}

			objToUpdate := patcher.New()
			if err := applyPatchToObject(codec, currentObjMap, originalPatchMap, objToUpdate, versionedObj); 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 request.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 < maxRetryWhenPatchConflicts && (errors.IsConflict(updateErr)); i++ {
			lastConflictErr = updateErr
			updateObject, _, updateErr = patcher.Update(ctx, name, updatedObjectInfo)
		}
		return updateObject, updateErr
	})
}
Example #2
0
// 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, 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 = request.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 := types.PatchType(contentType)

		patchJS, err := readBody(req.Request)
		if err != nil {
			scope.err(err, res.ResponseWriter, req.Request)
			return
		}

		s, ok := runtime.SerializerInfoForMediaType(scope.Serializer.SupportedMediaTypes(), runtime.ContentTypeJSON)
		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.Serializer, gv),
			scope.Serializer.DecoderToVersion(s.Serializer, schema.GroupVersion{Group: gv.Group, Version: runtime.APIVersionInternal}),
		)

		updateAdmit := func(updatedObject runtime.Object, currentObject runtime.Object) error {
			if admit != nil && admit.Handles(admission.Update) {
				userInfo, _ := request.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
		}

		responsewriters.WriteObject(http.StatusOK, scope.Kind.GroupVersion(), scope.Serializer, result, w, req.Request)
	}

}