| /* |
| * |
| * Copyright 2019 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package edsbalancer |
| |
| import ( |
| "encoding/json" |
| "fmt" |
| |
| "google.golang.org/grpc/balancer" |
| "google.golang.org/grpc/serviceconfig" |
| ) |
| |
| // EDSConfig represents the loadBalancingConfig section of the service config |
| // for EDS balancers. |
| type EDSConfig struct { |
| serviceconfig.LoadBalancingConfig |
| // ChildPolicy represents the load balancing config for the child |
| // policy. |
| ChildPolicy *loadBalancingConfig |
| // FallBackPolicy represents the load balancing config for the |
| // fallback. |
| FallBackPolicy *loadBalancingConfig |
| // Name to use in EDS query. If not present, defaults to the server |
| // name from the target URI. |
| EDSServiceName string |
| // LRS server to send load reports to. If not present, load reporting |
| // will be disabled. If set to the empty string, load reporting will |
| // be sent to the same server that we obtained CDS data from. |
| LrsLoadReportingServerName *string |
| } |
| |
| // edsConfigJSON is the intermediate unmarshal result of EDSConfig. ChildPolicy |
| // and Fallbackspolicy are post-processed, and for each, the first installed |
| // policy is kept. |
| type edsConfigJSON struct { |
| ChildPolicy []*loadBalancingConfig |
| FallbackPolicy []*loadBalancingConfig |
| EDSServiceName string |
| LRSLoadReportingServerName *string |
| } |
| |
| // UnmarshalJSON parses the JSON-encoded byte slice in data and stores it in l. |
| // When unmarshalling, we iterate through the childPolicy/fallbackPolicy lists |
| // and select the first LB policy which has been registered. |
| func (l *EDSConfig) UnmarshalJSON(data []byte) error { |
| var configJSON edsConfigJSON |
| if err := json.Unmarshal(data, &configJSON); err != nil { |
| return err |
| } |
| |
| l.EDSServiceName = configJSON.EDSServiceName |
| l.LrsLoadReportingServerName = configJSON.LRSLoadReportingServerName |
| |
| for _, lbcfg := range configJSON.ChildPolicy { |
| if balancer.Get(lbcfg.Name) != nil { |
| l.ChildPolicy = lbcfg |
| break |
| } |
| } |
| |
| for _, lbcfg := range configJSON.FallbackPolicy { |
| if balancer.Get(lbcfg.Name) != nil { |
| l.FallBackPolicy = lbcfg |
| break |
| } |
| } |
| return nil |
| } |
| |
| // MarshalJSON returns a JSON encoding of l. |
| func (l *EDSConfig) MarshalJSON() ([]byte, error) { |
| return nil, fmt.Errorf("EDSConfig.MarshalJSON() is unimplemented") |
| } |
| |
| // loadBalancingConfig represents a single load balancing config, |
| // stored in JSON format. |
| type loadBalancingConfig struct { |
| Name string |
| Config json.RawMessage |
| } |
| |
| // MarshalJSON returns a JSON encoding of l. |
| func (l *loadBalancingConfig) MarshalJSON() ([]byte, error) { |
| return nil, fmt.Errorf("loadBalancingConfig.MarshalJSON() is unimplemented") |
| } |
| |
| // UnmarshalJSON parses the JSON-encoded byte slice in data and stores it in l. |
| func (l *loadBalancingConfig) UnmarshalJSON(data []byte) error { |
| var cfg map[string]json.RawMessage |
| if err := json.Unmarshal(data, &cfg); err != nil { |
| return err |
| } |
| for name, config := range cfg { |
| l.Name = name |
| l.Config = config |
| } |
| return nil |
| } |