runc/libcontainer/console.go

75 lines
1.8 KiB
Go

package libcontainer
import (
"encoding/json"
"fmt"
"io"
"os"
)
// Console represents a pseudo TTY.
type Console interface {
io.ReadWriter
io.Closer
// Path returns the filesystem path to the slave side of the pty.
Path() string
// Fd returns the fd for the master of the pty.
File() *os.File
}
const (
TerminalInfoVersion uint32 = 201610041
TerminalInfoType uint8 = 'T'
)
// TerminalInfo is the structure which is passed as the non-ancillary data
// in the sendmsg(2) call when runc is run with --console-socket. It
// contains some information about the container which the console master fd
// relates to (to allow for consumers to use a single unix socket to handle
// multiple containers). This structure will probably move to runtime-spec
// at some point. But for now it lies in libcontainer.
type TerminalInfo struct {
// Version of the API.
Version uint32 `json:"version"`
// Type of message (future proofing).
Type uint8 `json:"type"`
// Container contains the ID of the container.
ContainerID string `json:"container_id"`
}
func (ti *TerminalInfo) String() string {
encoded, err := json.Marshal(*ti)
if err != nil {
panic(err)
}
return string(encoded)
}
func NewTerminalInfo(containerId string) *TerminalInfo {
return &TerminalInfo{
Version: TerminalInfoVersion,
Type: TerminalInfoType,
ContainerID: containerId,
}
}
func GetTerminalInfo(encoded string) (*TerminalInfo, error) {
ti := new(TerminalInfo)
if err := json.Unmarshal([]byte(encoded), ti); err != nil {
return nil, err
}
if ti.Type != TerminalInfoType {
return nil, fmt.Errorf("terminal info: incorrect type in payload (%q): %q", TerminalInfoType, ti.Type)
}
if ti.Version != TerminalInfoVersion {
return nil, fmt.Errorf("terminal info: incorrect version in payload (%q): %q", TerminalInfoVersion, ti.Version)
}
return ti, nil
}