This repository has been archived by the owner on Jan 14, 2020. It is now read-only.
/
cluster.go
234 lines (190 loc) · 6.32 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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
package integration
import (
"bytes"
"context"
"errors"
"fmt"
"net/url"
"os"
"sync"
"testing"
"time"
"github.com/beevik/etree"
"github.com/coreos/etcd/clientv3"
docker "github.com/fsouza/go-dockerclient"
"github.com/gocardless/pgsql-cluster-manager/pacemaker"
"github.com/stretchr/testify/require"
)
var networkTimeout = 10 * time.Second // wait for docker to allocate IPs
var startTimeout = 3 * time.Minute // wait for cluster to define master/sync/async
// Cluster wraps three postgres cluster members, providing the Roles method to inspect the
// roles of each node.
type Cluster struct {
client *docker.Client
members []*docker.Container
}
// Hostname returns the IP of the docker host
func (c *Cluster) Hostname(t *testing.T) string {
url, err := url.Parse(c.client.Endpoint())
require.Nil(t, err)
// If hostname is empty, we probably have a unix socket, implying we are the docker host
if hostname := url.Hostname(); hostname != "" {
return hostname
}
return "127.0.0.1"
}
// EtcdClient returns a client connection to the etcd cluster running on the cluster
// members.
func (c *Cluster) EtcdClient(t *testing.T) *clientv3.Client {
member := c.members[0]
hostPort := member.NetworkSettings.Ports["2379/tcp"][0].HostPort
client, err := clientv3.New(
clientv3.Config{
Endpoints: []string{fmt.Sprintf("http://%s:%s", c.Hostname(t), hostPort)},
DialTimeout: 3 * time.Second,
},
)
require.Nil(t, err)
return client
}
// Shutdown forcibly removes all containers
func (c *Cluster) Shutdown() {
for _, member := range c.members {
c.client.RemoveContainer(docker.RemoveContainerOptions{ID: member.ID, Force: true})
}
}
// Roles returns a triple of master, sync, async docker containers. When a role doesn't
// exist, the container will be nil.
func (c *Cluster) Roles(ctx context.Context) (*docker.Container, *docker.Container, *docker.Container) {
crm := pacemaker.NewPacemaker(pacemaker.WithExecutor(c.Executor()))
nodes, err := crm.Get(ctx, pacemaker.MasterXPath, pacemaker.SyncXPath, pacemaker.AsyncXPath)
if err != nil {
return nil, nil, nil
}
lookup := func(node *etree.Element) *docker.Container {
if node == nil {
return nil // the cluster doesn't have this member
}
if nodeName := node.SelectAttrValue("uname", ""); nodeName != "" {
for _, member := range c.members {
if member.Config.Hostname == nodeName {
return member
}
}
}
return nil
}
return lookup(nodes[0]), lookup(nodes[1]), lookup(nodes[2])
}
// Executor returns a handle to execute commands against a cluster member. It's assumed
// this will be to issue pacemaker commands, and so the caller does not care which member
// the command executes against.
func (c *Cluster) Executor() dockerExecutor {
return dockerExecutor{c.client, c.members[0]}
}
type dockerExecutor struct {
client *docker.Client
container *docker.Container
}
// CombinedOutput executes a command against the container and will block until it
// terminates, returning the command output as a byte slice.
func (e dockerExecutor) CombinedOutput(ctx context.Context, name string, args ...string) ([]byte, error) {
var output bytes.Buffer
exec, err := e.client.CreateExec(docker.CreateExecOptions{
AttachStderr: true,
AttachStdout: true,
Cmd: append([]string{name}, args...),
Container: e.container.ID,
Privileged: true,
})
if err != nil {
return nil, err
}
err = e.client.StartExec(exec.ID, docker.StartExecOptions{
Context: ctx,
Detach: false,
OutputStream: &output,
ErrorStream: &output,
})
if err != nil {
return nil, err
}
execStatus, err := e.client.InspectExec(exec.ID)
if execStatus.Running {
err = errors.New("exec'ed command has not finished")
}
if err == nil && execStatus.ExitCode != 0 {
err = fmt.Errorf("command exited with status %d", execStatus.ExitCode)
}
return output.Bytes(), err
}
func StartCluster(t *testing.T, ctx context.Context) *Cluster {
client, err := docker.NewClientFromEnv()
if err != nil {
require.Fail(t, "failed to initialise docker client: %s", err.Error())
}
createMember := func(name, workspaceDirectory string) *docker.Container {
c, err := client.CreateContainer(docker.CreateContainerOptions{
Context: ctx,
HostConfig: &docker.HostConfig{
Binds: []string{
fmt.Sprintf("%s:/pgsql-cluster-manager", workspaceDirectory),
"/var/run/docker.sock:/var/run/docker.sock",
},
Privileged: true,
PublishAllPorts: true,
},
Config: &docker.Config{
Hostname: name,
Entrypoint: []string{"/usr/bin/dumb-init", "--"},
Cmd: []string{"bash", "-c", "while :; do sleep 1; done"},
Image: "gocardless/postgres-member",
ExposedPorts: map[docker.Port]struct{}{
"6432/tcp": struct{}{}, // PGBouncer
"2379/tcp": struct{}{}, // etcd
},
},
})
require.Nil(t, err)
require.Nil(t, client.StartContainerWithContext(c.ID, nil, ctx))
timeout := time.After(networkTimeout)
for {
select {
case <-timeout:
require.Fail(t, fmt.Sprintf("timed out waiting for container [%s] to receive IP", c.ID))
default:
c, err := client.InspectContainer(c.ID)
require.Nil(t, err)
if c.NetworkSettings != nil && c.NetworkSettings.IPAddress != "" {
return c
}
}
}
}
workspaceDirectory, found := os.LookupEnv("PGSQL_WORKSPACE")
require.True(t, found, "test requires PGSQL_WORKSPACE to be set")
_, err = os.Stat(fmt.Sprintf("%s/pgsql-cluster-manager.linux_amd64", workspaceDirectory))
require.Nil(t, err, "Need pgsql-cluster-manager.linux_amd64 binary")
pg01 := createMember("pg01", workspaceDirectory)
pg02 := createMember("pg02", workspaceDirectory)
pg03 := createMember("pg03", workspaceDirectory)
ids := []string{pg01.ID, pg02.ID, pg03.ID}
startMember := func(node *docker.Container) {
_, err := dockerExecutor{client, node}.CombinedOutput(ctx, "/bin/start-cluster", ids...)
require.Nil(t, err)
}
var wg sync.WaitGroup
ready := make(chan struct{}, 1)
wg.Add(3)
go func() { startMember(pg01); wg.Done() }()
go func() { startMember(pg02); wg.Done() }()
go func() { startMember(pg03); wg.Done() }()
go func() { wg.Wait(); ready <- struct{}{} }()
select {
case <-time.After(startTimeout):
require.Fail(t, "timed out waiting for cluster to start")
case <-ready:
// Cluster is ready!
}
return &Cluster{client: client, members: []*docker.Container{pg01, pg02, pg03}}
}