blob: 9b59cfa01ab330c61127f5eeafd60118e3320306 [file] [log] [blame]
/*
*
* 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
}