ctop/connector/manager/docker.go
2018-10-28 13:43:24 +02:00

148 lines
3.1 KiB
Go

package manager
import (
"fmt"
api "github.com/fsouza/go-dockerclient"
"github.com/pkg/errors"
"io"
"os"
)
type Docker struct {
id string
client *api.Client
}
func NewDocker(client *api.Client, id string) *Docker {
return &Docker{
id: id,
client: client,
}
}
// Do not allow to close reader (i.e. /dev/stdin which docker client tries to close after command execution)
type noClosableReader struct {
wrappedReader io.Reader
}
func (w *noClosableReader) Read(p []byte) (n int, err error) {
return w.wrappedReader.Read(p)
}
const (
STDIN = 0
STDOUT = 1
STDERR = 2
)
var (
wrongFrameFormat = errors.New("Wrong frame format")
)
// A frame has a Header and a Payload
// Header: [8]byte{STREAM_TYPE, 0, 0, 0, SIZE1, SIZE2, SIZE3, SIZE4}
// STREAM_TYPE can be:
// 0: stdin (is written on stdout)
// 1: stdout
// 2: stderr
// SIZE1, SIZE2, SIZE3, SIZE4 are the four bytes of the uint32 size encoded as big endian.
// But we don't use size, because we don't need to find the end of frame.
type frameWriter struct {
stdout io.Writer
stderr io.Writer
stdin io.Writer
}
func (w *frameWriter) Write(p []byte) (n int, err error) {
if len(p) > 8 {
var targetWriter io.Writer
switch p[0] {
case STDIN:
targetWriter = w.stdin
break
case STDOUT:
targetWriter = w.stdout
break
case STDERR:
targetWriter = w.stderr
break
default:
return 0, wrongFrameFormat
}
n, err := targetWriter.Write(p[8:])
return n + 8, err
}
return 0, wrongFrameFormat
}
func (dc *Docker) Exec(cmd []string) error {
execCmd, err := dc.client.CreateExec(api.CreateExecOptions{
AttachStdin: true,
AttachStdout: true,
AttachStderr: true,
Cmd: cmd,
Container: dc.id,
Tty: true,
})
if err != nil {
return err
}
return dc.client.StartExec(execCmd.ID, api.StartExecOptions{
InputStream: &noClosableReader{os.Stdin},
OutputStream: &frameWriter{os.Stdout, os.Stderr, os.Stdin},
ErrorStream: os.Stderr,
RawTerminal: true,
})
}
func (dc *Docker) Start() error {
c, err := dc.client.InspectContainer(dc.id)
if err != nil {
return fmt.Errorf("cannot inspect container: %v", err)
}
if err := dc.client.StartContainer(c.ID, c.HostConfig); err != nil {
return fmt.Errorf("cannot start container: %v", err)
}
return nil
}
func (dc *Docker) Stop() error {
if err := dc.client.StopContainer(dc.id, 3); err != nil {
return fmt.Errorf("cannot stop container: %v", err)
}
return nil
}
func (dc *Docker) Remove() error {
if err := dc.client.RemoveContainer(api.RemoveContainerOptions{ID: dc.id}); err != nil {
return fmt.Errorf("cannot remove container: %v", err)
}
return nil
}
func (dc *Docker) Pause() error {
if err := dc.client.PauseContainer(dc.id); err != nil {
return fmt.Errorf("cannot pause container: %v", err)
}
return nil
}
func (dc *Docker) Unpause() error {
if err := dc.client.UnpauseContainer(dc.id); err != nil {
return fmt.Errorf("cannot unpause container: %v", err)
}
return nil
}
func (dc *Docker) Restart() error {
if err := dc.client.RestartContainer(dc.id, 3); err != nil {
return fmt.Errorf("cannot restart container: %v", err)
}
return nil
}