grpc-go/xds/internal/clusterspecifier/rls/rls.go

106 lines
3.5 KiB
Go

/*
*
* Copyright 2021 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 rls implements the RLS cluster specifier plugin.
package rls
import (
"encoding/json"
"fmt"
"google.golang.org/grpc/balancer"
"google.golang.org/grpc/internal"
rlspb "google.golang.org/grpc/internal/proto/grpc_lookup_v1"
"google.golang.org/grpc/xds/internal/clusterspecifier"
"google.golang.org/protobuf/encoding/protojson"
"google.golang.org/protobuf/proto"
"google.golang.org/protobuf/types/known/anypb"
)
func init() {
clusterspecifier.Register(rls{})
// TODO: Remove these once the RLS env var is removed.
internal.RegisterRLSClusterSpecifierPluginForTesting = func() {
clusterspecifier.Register(rls{})
}
internal.UnregisterRLSClusterSpecifierPluginForTesting = func() {
for _, typeURL := range rls.TypeURLs(rls{}) {
clusterspecifier.UnregisterForTesting(typeURL)
}
}
}
type rls struct{}
func (rls) TypeURLs() []string {
return []string{"type.googleapis.com/grpc.lookup.v1.RouteLookupClusterSpecifier"}
}
// lbConfigJSON is the RLS LB Policies configuration in JSON format.
// RouteLookupConfig will be a raw JSON string from the passed in proto
// configuration, and the other fields will be hardcoded.
type lbConfigJSON struct {
RouteLookupConfig json.RawMessage `json:"routeLookupConfig"`
ChildPolicy []map[string]json.RawMessage `json:"childPolicy"`
ChildPolicyConfigTargetFieldName string `json:"childPolicyConfigTargetFieldName"`
}
func (rls) ParseClusterSpecifierConfig(cfg proto.Message) (clusterspecifier.BalancerConfig, error) {
if cfg == nil {
return nil, fmt.Errorf("rls_csp: nil configuration message provided")
}
m, ok := cfg.(*anypb.Any)
if !ok {
return nil, fmt.Errorf("rls_csp: error parsing config %v: unknown type %T", cfg, cfg)
}
rlcs := new(rlspb.RouteLookupClusterSpecifier)
if err := m.UnmarshalTo(rlcs); err != nil {
return nil, fmt.Errorf("rls_csp: error parsing config %v: %v", cfg, err)
}
rlcJSON, err := protojson.Marshal(rlcs.GetRouteLookupConfig())
if err != nil {
return nil, fmt.Errorf("rls_csp: error marshaling route lookup config: %v: %v", rlcs.GetRouteLookupConfig(), err)
}
lbCfgJSON := &lbConfigJSON{
RouteLookupConfig: rlcJSON, // "JSON form of RouteLookupClusterSpecifier.config" - RLS in xDS Design Doc
ChildPolicy: []map[string]json.RawMessage{
{
"cds_experimental": json.RawMessage("{}"),
},
},
ChildPolicyConfigTargetFieldName: "cluster",
}
rawJSON, err := json.Marshal(lbCfgJSON)
if err != nil {
return nil, fmt.Errorf("rls_csp: error marshaling load balancing config %v: %v", lbCfgJSON, err)
}
rlsBB := balancer.Get(internal.RLSLoadBalancingPolicyName)
if rlsBB == nil {
return nil, fmt.Errorf("RLS LB policy not registered")
}
if _, err = rlsBB.(balancer.ConfigParser).ParseConfig(rawJSON); err != nil {
return nil, fmt.Errorf("rls_csp: validation error from rls lb policy parsing: %v", err)
}
return clusterspecifier.BalancerConfig{{internal.RLSLoadBalancingPolicyName: lbCfgJSON}}, nil
}