forked from cpuguy83/drax
/
cluster.go
181 lines (155 loc) · 3.63 KB
/
cluster.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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
package raftkv
import (
"crypto/tls"
"fmt"
"net"
"os"
"path/filepath"
"strings"
"sync"
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/raftkv/api"
libkvstore "github.com/docker/libkv/store"
"github.com/hashicorp/raft"
)
var (
DefaultRaftPort = "2380"
defaultTimeout = 5 * time.Second
)
type Cluster struct {
home, addr, peerAddr string
store *store
chShutdown chan struct{}
chErrors chan error
server *RPCServer
tlsConfig *tls.Config
l net.Listener
r *Raft
mu sync.Mutex
}
func New(l net.Listener, home, addr, peer string, tlsConfig *tls.Config) (*Cluster, error) {
if err := os.MkdirAll(home, 0600); err != nil {
return nil, fmt.Errorf("error creating home dir: %v", err)
}
c := &Cluster{
home: home,
addr: addr,
peerAddr: peer,
chShutdown: make(chan struct{}),
chErrors: make(chan error, 1),
l: l,
}
return c, c.start()
}
func (c *Cluster) start() error {
c.store = newStore()
cfg := raft.DefaultConfig()
cfg.ShutdownOnRemove = false
// setup K/V store
raftStream, err := newStreamLayer(c.l.Addr(), c.tlsConfig, raftMessage)
if err != nil {
return err
}
raftTransport := raft.NewNetworkTransport(raftStream, 3, defaultTimeout, os.Stdout)
peerStore := newPeerStore(c.home, raftTransport)
peers, err := peerStore.Peers()
if err != nil {
return err
}
nPeers := len(peers)
if nPeers <= 1 && c.peerAddr == "" {
cfg.EnableSingleNode = true
}
kvRaft, err := newRaft(filepath.Join(c.home, "raft"), c.addr, peerStore, (*storeFSM)(c.store), raftTransport, cfg)
if err != nil {
return err
}
c.store.r = kvRaft
kvRaft.store = c.store
nodeRPCStream, err := newStreamLayer(c.l.Addr(), c.tlsConfig, api.RPCMessage)
if err != nil {
return err
}
nodeRPC := &nodeRPC{nodeRPCStream, kvRaft}
go nodeRPC.handleConns()
clientRPCStream, err := newStreamLayer(c.l.Addr(), c.tlsConfig, api.ClientMessage)
if err != nil {
return err
}
clientRPC := &clientRPC{clientRPCStream, c.store}
go clientRPC.handleConns()
handlers := map[api.MessageType]rpcHandler{
raftMessage: raftStream,
api.RPCMessage: nodeRPCStream,
api.ClientMessage: clientRPCStream,
}
c.server = newRPCServer(c.l, handlers)
c.r = kvRaft
go c.store.waitLeader()
go c.waitLeader()
if c.peerAddr != "" && nPeers <= 1 {
res, err := rpc(c.peerAddr, &rpcRequest{
Method: addNode,
Args: []string{c.addr},
}, c.tlsConfig)
if err != nil {
return err
}
if res.Err != "" && !strings.Contains(res.Err, "peer already known") {
return fmt.Errorf(res.Err)
}
}
return nil
}
func (c *Cluster) Shutdown() {
c.mu.Lock()
defer c.mu.Unlock()
select {
case <-c.chShutdown:
c.chErrors <- fmt.Errorf("already shutdown")
return
default:
}
c.r.Close()
close(c.chShutdown)
}
func (c *Cluster) KVStore() libkvstore.Store {
return c.store
}
func (c *Cluster) ShutdownCh() <-chan struct{} {
return c.chShutdown
}
func (c *Cluster) Errors() <-chan error {
return c.chErrors
}
func (c *Cluster) waitLeader() {
leaderCh := c.r.LeaderCh()
for {
logrus.Info("cluster: waiting for leader")
select {
case <-c.chShutdown:
return
case state := <-leaderCh:
if state == raft.Leader {
c.handleLeader(leaderCh)
}
}
}
}
func (c *Cluster) handleLeader(leaderCh <-chan interface{}) {
for {
select {
case <-c.chShutdown:
return
case state := <-leaderCh:
if state != raft.Leader {
return
}
default:
}
// Handle cluster-level leadership resonsibilities
logrus.Debug("cluster: handling leadership")
time.Sleep(5 * time.Second)
}
}