-
Notifications
You must be signed in to change notification settings - Fork 7
/
resolver.go
155 lines (135 loc) · 3.97 KB
/
resolver.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
// Copyright 2019-present Open Networking Foundation.
//
// 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 rsm
import (
"context"
"fmt"
"github.com/atomix/atomix-go-framework/pkg/atomix/cluster"
"github.com/atomix/atomix-go-framework/pkg/atomix/storage/protocol/rsm"
"github.com/atomix/atomix-go-framework/pkg/atomix/util/retry"
"google.golang.org/grpc"
"google.golang.org/grpc/attributes"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/resolver"
"google.golang.org/grpc/serviceconfig"
)
const resolverName = "rsm"
func newResolver(partition cluster.Partition) resolver.Builder {
return &ResolverBuilder{
partition: partition,
}
}
type ResolverBuilder struct {
partition cluster.Partition
}
func (b *ResolverBuilder) Scheme() string {
return resolverName
}
func (b *ResolverBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
var dialOpts []grpc.DialOption
if opts.DialCreds != nil {
dialOpts = append(
dialOpts,
grpc.WithTransportCredentials(opts.DialCreds),
)
} else {
dialOpts = append(dialOpts, grpc.WithInsecure())
}
dialOpts = append(dialOpts, grpc.WithUnaryInterceptor(retry.RetryingUnaryClientInterceptor(retry.WithRetryOn(codes.Unavailable, codes.Unknown))))
dialOpts = append(dialOpts, grpc.WithStreamInterceptor(retry.RetryingStreamClientInterceptor(retry.WithRetryOn(codes.Unavailable, codes.Unknown))))
dialOpts = append(dialOpts, grpc.WithContextDialer(opts.Dialer))
resolverConn, err := grpc.Dial(target.Endpoint, dialOpts...)
if err != nil {
return nil, err
}
serviceConfig := cc.ParseServiceConfig(
fmt.Sprintf(`{"loadBalancingConfig":[{"%s":{}}]}`, resolverName),
)
resolver := &Resolver{
partitionID: rsm.PartitionID(b.partition.ID()),
clientConn: cc,
resolverConn: resolverConn,
serviceConfig: serviceConfig,
}
err = resolver.start()
if err != nil {
return nil, err
}
return resolver, nil
}
var _ resolver.Builder = (*ResolverBuilder)(nil)
type Resolver struct {
partitionID rsm.PartitionID
clientConn resolver.ClientConn
resolverConn *grpc.ClientConn
serviceConfig *serviceconfig.ParseResult
}
func (r *Resolver) start() error {
client := rsm.NewPartitionServiceClient(r.resolverConn)
request := &rsm.PartitionConfigRequest{
PartitionID: r.partitionID,
}
stream, err := client.WatchConfig(context.Background(), request)
if err != nil {
return err
}
response, err := stream.Recv()
if err != nil {
return err
}
r.updateState(response)
go func() {
for {
response, err := stream.Recv()
if err != nil {
return
}
r.updateState(response)
}
}()
return nil
}
func (r *Resolver) updateState(response *rsm.PartitionConfigResponse) {
log.Debugf("Updating connections for partition config %+v", response)
var addrs []resolver.Address
addrs = append(addrs, resolver.Address{
Addr: response.Leader,
Type: resolver.Backend,
Attributes: attributes.New(
"is_leader",
true,
),
})
for _, server := range response.Followers {
addrs = append(addrs, resolver.Address{
Addr: server,
Type: resolver.Backend,
Attributes: attributes.New(
"is_leader",
false,
),
})
}
r.clientConn.UpdateState(resolver.State{
Addresses: addrs,
ServiceConfig: r.serviceConfig,
})
}
func (r *Resolver) ResolveNow(resolver.ResolveNowOptions) {}
func (r *Resolver) Close() {
if err := r.resolverConn.Close(); err != nil {
log.Error("failed to close conn", err)
}
}
var _ resolver.Resolver = (*Resolver)(nil)