runc/exec.go

83 lines
1.8 KiB
Go

// +build linux
package main
import (
"encoding/json"
"fmt"
"os"
"github.com/Sirupsen/logrus"
"github.com/codegangsta/cli"
"github.com/opencontainers/specs"
)
var execCommand = cli.Command{
Name: "exec",
Usage: "execute new process inside the container",
Flags: []cli.Flag{
cli.StringFlag{
Name: "console",
Value: "",
Usage: "specify the pty slave path for use with the container",
},
},
Action: func(context *cli.Context) {
config, err := loadProcessConfig(context.Args().First())
if err != nil {
fatal(err)
}
if os.Geteuid() != 0 {
logrus.Fatal("runc should be run as root")
}
if config.Args == nil {
logrus.Fatal("args missing in process configuration")
}
status, err := execProcess(context, config)
if err != nil {
logrus.Fatalf("exec failed: %v", err)
}
os.Exit(status)
},
}
func execProcess(context *cli.Context, config *specs.Process) (int, error) {
container, err := getContainer(context)
if err != nil {
return -1, err
}
process := newProcess(*config)
rootuid, err := container.Config().HostUID()
if err != nil {
return -1, err
}
tty, err := newTty(config.Terminal, process, rootuid, context.String("console"))
if err != nil {
return -1, err
}
handler := newSignalHandler(tty)
defer handler.Close()
if err := container.Start(process); err != nil {
return -1, err
}
return handler.forward(process)
}
// loadProcessConfig loads the process configuration from the provided path.
func loadProcessConfig(path string) (*specs.Process, error) {
f, err := os.Open(path)
if err != nil {
if os.IsNotExist(err) {
return nil, fmt.Errorf("JSON configuration file for %s not found", path)
}
return nil, err
}
defer f.Close()
var s *specs.Process
if err := json.NewDecoder(f).Decode(&s); err != nil {
return nil, err
}
return s, nil
}