aboutsummaryrefslogtreecommitdiff
path: root/libpod/container_attach.go
blob: 46b306133bd7e6749eee9a60ead55b89685108ef (plain)
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
package libpod

import (
	"fmt"
	"io"
	"net"
	"os"
	"path/filepath"

	"github.com/docker/docker/pkg/term"
	"github.com/pkg/errors"
	"github.com/projectatomic/libpod/utils"
	"github.com/sirupsen/logrus"
	"golang.org/x/crypto/ssh/terminal"
	"golang.org/x/sys/unix"
	"k8s.io/client-go/tools/remotecommand"
	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
)

/* Sync with stdpipe_t in conmon.c */
const (
	AttachPipeStdin  = 1
	AttachPipeStdout = 2
	AttachPipeStderr = 3
)

// attachContainerSocket connects to the container's attach socket and deals with the IO
func (c *Container) attachContainerSocket(resize <-chan remotecommand.TerminalSize, noStdIn bool, detachKeys []byte, attached chan<- bool) error {
	inputStream := os.Stdin
	outputStream := os.Stdout
	errorStream := os.Stderr
	defer inputStream.Close()

	// TODO Renable this when tty/terminal discussion is had.
	/*
		tty, err := strconv.ParseBool(c.runningSpec.Annotations["io.kubernetes.cri-o.TTY"])
		if err != nil {
			return errors.Wrapf(err, "unable to parse annotations in %s", c.ID)
		}
		if !tty {
			return errors.Errorf("no tty available for %s", c.ID())
		}
	*/

	if terminal.IsTerminal(int(inputStream.Fd())) {
		oldTermState, err := term.SaveState(inputStream.Fd())
		if err != nil {
			return errors.Wrapf(err, "unable to save terminal state")
		}

		defer term.RestoreTerminal(inputStream.Fd(), oldTermState)
	}

	// Put both input and output into raw
	if !noStdIn {
		term.SetRawTerminal(inputStream.Fd())
	}

	controlPath := filepath.Join(c.bundlePath(), "ctl")
	controlFile, err := os.OpenFile(controlPath, unix.O_WRONLY, 0)
	if err != nil {
		return errors.Wrapf(err, "failed to open container ctl file: %v")
	}
	defer controlFile.Close()

	kubecontainer.HandleResizing(resize, func(size remotecommand.TerminalSize) {
		logrus.Debugf("Received a resize event: %+v", size)
		_, err := fmt.Fprintf(controlFile, "%d %d %d\n", 1, size.Height, size.Width)
		if err != nil {
			logrus.Warnf("Failed to write to control file to resize terminal: %v", err)
		}
	})
	logrus.Debug("connecting to socket ", c.attachSocketPath())

	conn, err := net.DialUnix("unixpacket", nil, &net.UnixAddr{Name: c.attachSocketPath(), Net: "unixpacket"})
	if err != nil {
		return errors.Wrapf(err, "failed to connect to container's attach socket: %v")
	}
	defer conn.Close()

	// signal back that the connection was made
	attached <- true

	receiveStdoutError := make(chan error)
	if outputStream != nil || errorStream != nil {
		go func() {
			receiveStdoutError <- redirectResponseToOutputStreams(outputStream, errorStream, conn)
		}()
	}

	stdinDone := make(chan error)
	go func() {
		var err error
		if inputStream != nil && !noStdIn {
			_, err = utils.CopyDetachable(conn, inputStream, detachKeys)
			conn.CloseWrite()
		}
		stdinDone <- err
	}()

	select {
	case err := <-receiveStdoutError:
		return err
	case err := <-stdinDone:
		if _, ok := err.(utils.DetachError); ok {
			return nil
		}
		if outputStream != nil || errorStream != nil {
			return <-receiveStdoutError
		}
	}
	return nil
}

func redirectResponseToOutputStreams(outputStream, errorStream io.Writer, conn io.Reader) error {
	var err error
	buf := make([]byte, 8192+1) /* Sync with conmon STDIO_BUF_SIZE */
	for {
		nr, er := conn.Read(buf)
		if nr > 0 {
			var dst io.Writer
			switch buf[0] {
			case AttachPipeStdout:
				dst = outputStream
			case AttachPipeStderr:
				dst = errorStream
			default:
				logrus.Infof("Received unexpected attach type %+d", buf[0])
			}

			if dst != nil {
				nw, ew := dst.Write(buf[1:nr])
				if ew != nil {
					err = ew
					break
				}
				if nr != nw+1 {
					err = io.ErrShortWrite
					break
				}
			}
		}
		if er == io.EOF {
			break
		}
		if er != nil {
			err = er
			break
		}
	}
	return err
}