This repository has been archived by the owner on Jun 23, 2020. It is now read-only.
/
discovery.go
104 lines (85 loc) · 2.8 KB
/
discovery.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
package discovery
import (
"context"
"fmt"
"net"
"github.com/Gufran/flightpath/log"
api "github.com/envoyproxy/go-control-plane/envoy/api/v2"
sd "github.com/envoyproxy/go-control-plane/envoy/service/discovery/v2"
"github.com/envoyproxy/go-control-plane/pkg/cache"
dss "github.com/envoyproxy/go-control-plane/pkg/server"
"github.com/google/uuid"
consul "github.com/hashicorp/consul/api"
"google.golang.org/grpc"
)
var logger = log.New("discovery")
func getConsulClient(c *ConsulConfig) (*consul.Client, error) {
cfg := consul.DefaultConfig()
cfg.Address = fmt.Sprintf("%s://%s:%d", c.Proto, c.Host, c.Port)
cfg.Token = c.Token
return consul.NewClient(cfg)
}
func Start(ctx context.Context, config *Config) (func(), error) {
cc, err := getConsulClient(config.Consul)
if err != nil {
return nil, fmt.Errorf("failed to create consul client. %s", err)
}
apicache := cache.NewSnapshotCache(false, cache.IDHash{}, log.NewSrvLogger())
xds := dss.NewServer(apicache, nil)
server := grpc.NewServer()
sid, err := registerSelf(cc, config.XDS.ServiceName, config.XDS.ListenPort)
if err != nil {
return nil, fmt.Errorf("failed to register the service in consul catalog. %s", err)
}
config.XDS.Init(cc, apicache)
config.XDS.Start(ctx)
sd.RegisterAggregatedDiscoveryServiceServer(server, xds)
api.RegisterEndpointDiscoveryServiceServer(server, xds)
api.RegisterClusterDiscoveryServiceServer(server, xds)
api.RegisterRouteDiscoveryServiceServer(server, xds)
api.RegisterListenerDiscoveryServiceServer(server, xds)
listener, err := net.Listen("tcp", fmt.Sprintf(":%d", config.XDS.ListenPort))
if err != nil {
return nil, fmt.Errorf("failed to start network listener on port %d. %s", config.XDS.ListenPort, err)
}
go func() {
err := server.Serve(listener)
if err != nil {
logger.WithError(err).Error("GRPC server failed")
}
}()
return func() {
err := deregisterSelf(cc, sid)
if err != nil {
logger.WithError(err).Error("failed to deregister the service from consul catalog")
}
server.Stop()
err = listener.Close()
if err != nil {
logger.WithError(err).Error("failed to stop the socket listener")
}
}, nil
}
func registerSelf(cc *consul.Client, name string, port int) (string, error) {
reg := &consul.AgentServiceRegistration{
ID: uuid.New().String(),
Name: name,
Kind: consul.ServiceKindTypical,
Port: port,
Connect: &consul.AgentServiceConnect{
Native: true,
},
// TODO: register health checks at least for the TCP
// socket connection. Expand the health checks to
// cover the GRPC interface and some basic endpoints
// so that failures can be detected early on
}
err := cc.Agent().ServiceRegister(reg)
if err != nil {
return "", err
}
return reg.ID, nil
}
func deregisterSelf(cc *consul.Client, sid string) error {
return cc.Agent().ServiceDeregister(sid)
}