-
Notifications
You must be signed in to change notification settings - Fork 18
/
remoteagent.go
224 lines (188 loc) · 5.42 KB
/
remoteagent.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
package remoteagent
import (
"bufio"
"context"
"errors"
"fmt"
"github.com/avast/retry-go"
"github.com/cirruslabs/cirrus-cli/internal/executor/endpoint"
"github.com/cirruslabs/cirrus-cli/internal/executor/instance/runconfig"
"github.com/cirruslabs/cirrus-cli/internal/logger"
"golang.org/x/crypto/ssh"
"io"
"net"
"strconv"
"strings"
"time"
)
var ErrFailed = errors.New("remote agent failed")
type WaitForAgentHook func(ctx context.Context, sshClient *ssh.Client) error
func WaitForAgent(
ctx context.Context,
logger logger.Lightweight,
ip string,
sshUser string,
sshPassword string,
agentOS string,
agentArchitecture string,
config *runconfig.RunConfig,
synchronizeTime bool,
initializeHooks []WaitForAgentHook,
terminateHooks []WaitForAgentHook,
preCreatedWorkingDir string,
) error {
// Connect to the VM and upload the agent
var netConn net.Conn
var err error
addr := ip + ":22"
if err := retry.Do(func() error {
dialer := net.Dialer{}
netConn, err = dialer.DialContext(ctx, "tcp", addr)
return err
}, retry.Context(ctx)); err != nil {
return fmt.Errorf("%w: failed to connect via SSH: %v", ErrFailed, err)
}
sshConfig := &ssh.ClientConfig{
HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
return nil
},
User: sshUser,
Auth: []ssh.AuthMethod{
ssh.Password(sshPassword),
},
}
sshConn, chans, reqs, err := ssh.NewClientConn(netConn, addr, sshConfig)
if err != nil {
return fmt.Errorf("%w: failed to connect via SSH: %v", ErrFailed, err)
}
cli := ssh.NewClient(sshConn, chans, reqs)
// Work around x/crypto/ssh not being context.Context-friendly (e.g. https://github.com/golang/go/issues/20288)
monitorCtx, monitorCancel := context.WithCancel(ctx)
go func() {
<-monitorCtx.Done()
_ = cli.Close()
}()
defer monitorCancel()
for _, hook := range initializeHooks {
if err := hook(ctx, cli); err != nil {
return err
}
}
remoteAgentPath, err := uploadAgent(ctx, cli, agentOS, config.GetAgentVersion(), agentArchitecture)
if err != nil {
return fmt.Errorf("%w: failed to upload agent via SFTP: %v",
ErrFailed, err)
}
sess, err := cli.NewSession()
if err != nil {
return fmt.Errorf("%w: failed to open SSH session: %v", ErrFailed, err)
}
// Log output from the virtual machine
stdout, err := sess.StdoutPipe()
if err != nil {
return fmt.Errorf("%w: while opening stdout pipe: %v", ErrFailed, err)
}
stderr, err := sess.StderrPipe()
if err != nil {
return fmt.Errorf("%w: while opening stderr pipe: %v", ErrFailed, err)
}
go func() {
output := io.MultiReader(stdout, stderr)
scanner := bufio.NewScanner(output)
for scanner.Scan() {
logger.Debugf("VM: %s", scanner.Text())
}
}()
stdinBuf, err := sess.StdinPipe()
if err != nil {
return fmt.Errorf("%w: while opening stdin pipe: %v", ErrFailed, err)
}
// start a login shell so all the customization from ~/.zprofile will be picked up
err = sess.Shell()
if err != nil {
return fmt.Errorf("%w: failed to start a shell: %v", ErrFailed, err)
}
// Synchronize time for suspended VMs
if synchronizeTime {
_, err = stdinBuf.Write([]byte(TimeSyncCommand(time.Now().UTC())))
if err != nil {
return fmt.Errorf("%w: failed to sync time: %v", ErrFailed, err)
}
}
var apiEndpoint string
switch config.Endpoint.(type) {
case *endpoint.Local:
// Expose local RPC service to the VM via SSH port forwarding
vmListener, err := cli.Listen("tcp", "127.0.0.1:0")
if err != nil {
return fmt.Errorf("%w: failed to set-up SSH port forwarding: %v", ErrFailed, err)
}
defer vmListener.Close()
go forwardViaSSH(vmListener, logger, config.Endpoint.Direct())
apiEndpoint = "http://" + vmListener.Addr().String()
default:
apiEndpoint = config.Endpoint.Direct()
}
command := []string{
remoteAgentPath,
"-api-endpoint",
apiEndpoint,
"-server-token",
"\"" + config.ServerSecret + "\"",
"-client-token",
"\"" + config.ClientSecret + "\"",
"-task-id",
strconv.FormatInt(config.TaskID, 10),
}
if preCreatedWorkingDir != "" {
command = append(command, "-pre-created-working-dir", "\""+preCreatedWorkingDir+"\"")
}
// Start the agent and wait for it to terminate
_, err = stdinBuf.Write([]byte(strings.Join(command, " ") + "\nexit\n"))
if err != nil {
return fmt.Errorf("%w: failed to start agent: %v", ErrFailed, err)
}
err = sess.Wait()
if err != nil {
// Work around x/crypto/ssh not being context.Context-friendly (e.g. https://github.com/golang/go/issues/20288)
if err := monitorCtx.Err(); err != nil {
return err
}
return fmt.Errorf("%w: failed to run agent: %v", ErrFailed, err)
}
for _, hook := range terminateHooks {
if err := hook(ctx, cli); err != nil {
return err
}
}
return nil
}
func forwardViaSSH(vmListener net.Listener, logger logger.Lightweight, endpoint string) {
for {
vmConn, err := vmListener.Accept()
if err != nil {
if errors.Is(err, io.EOF) {
return
}
logger.Debugf("failed to accept connection from the VM on forwarded port: %v", err)
continue
}
// Convert endpoint address to host
host := strings.TrimPrefix(endpoint, "http://")
localConn, err := net.Dial("tcp", host)
if err != nil {
logger.Debugf("failed to connect to the RPC service on %s: %v", endpoint, err)
continue
}
go func() {
defer vmConn.Close()
defer localConn.Close()
_, _ = io.Copy(vmConn, localConn)
}()
go func() {
defer vmConn.Close()
defer localConn.Close()
_, _ = io.Copy(localConn, vmConn)
}()
}
}