runc/start.go

124 lines
3.2 KiB
Go

// +build linux
package main
import (
"os"
"runtime"
"github.com/codegangsta/cli"
"github.com/coreos/go-systemd/activation"
"github.com/opencontainers/runc/libcontainer"
"github.com/opencontainers/specs/specs-go"
)
// default action is to start a container
var startCommand = cli.Command{
Name: "start",
Usage: "create and run a container",
ArgsUsage: `<container-id>
Where "<container-id>" is your name for the instance of the container that you
are starting. The name you provide for the container instance must be unique on
your host.`,
Description: `The start command creates an instance of a container for a bundle. The bundle
is a directory with a specification file and a root filesystem.`,
Flags: []cli.Flag{
cli.StringFlag{
Name: "bundle, b",
Value: "",
Usage: `path to the root of the bundle directory, defaults to the current directory`,
},
cli.StringFlag{
Name: "console",
Value: "",
Usage: "specify the pty slave path for use with the container",
},
cli.BoolFlag{
Name: "detach,d",
Usage: "detach from the container's process",
},
cli.StringFlag{
Name: "pid-file",
Value: "",
Usage: "specify the file to write the process id to",
},
cli.BoolFlag{
Name: "no-subreaper",
Usage: "disable the use of the subreaper used to reap reparented processes",
},
},
Action: func(context *cli.Context) {
bundle := context.String("bundle")
if bundle != "" {
if err := os.Chdir(bundle); err != nil {
fatal(err)
}
}
spec, err := loadSpec(specConfig)
if err != nil {
fatal(err)
}
notifySocket := os.Getenv("NOTIFY_SOCKET")
if notifySocket != "" {
setupSdNotify(spec, notifySocket)
}
if os.Geteuid() != 0 {
fatalf("runc should be run as root")
}
status, err := startContainer(context, spec)
if err != nil {
fatal(err)
}
// exit with the container's exit status so any external supervisor is
// notified of the exit with the correct exit status.
os.Exit(status)
},
}
var initCommand = cli.Command{
Name: "init",
Usage: `initialize the namespaces and launch the process (do not call it outside of runc)`,
Action: func(context *cli.Context) {
runtime.GOMAXPROCS(1)
runtime.LockOSThread()
factory, _ := libcontainer.New("")
if err := factory.StartInitialization(); err != nil {
// as the error is sent back to the parent there is no need to log
// or write it to stderr because the parent process will handle this
os.Exit(1)
}
panic("libcontainer: container init failed to exec")
},
}
func startContainer(context *cli.Context, spec *specs.Spec) (int, error) {
id := context.Args().First()
if id == "" {
return -1, errEmptyID
}
container, err := createContainer(context, id, spec)
if err != nil {
return -1, err
}
detach := context.Bool("detach")
// Support on-demand socket activation by passing file descriptors into the container init process.
listenFDs := []*os.File{}
if os.Getenv("LISTEN_FDS") != "" {
listenFDs = activation.Files(false)
}
r := &runner{
enableSubreaper: !context.Bool("no-subreaper"),
shouldDestroy: true,
container: container,
listenFDs: listenFDs,
console: context.String("console"),
detach: detach,
pidFile: context.String("pid-file"),
}
return r.run(&spec.Process)
}