binctr/examples/busybox/main.go
Jess Frazelle cdd93563f5 add better generate
Signed-off-by: Jess Frazelle <acidburn@microsoft.com>
2018-03-20 01:33:56 -04:00

88 lines
1.8 KiB
Go

package main
import (
"flag"
"os"
"runtime"
"github.com/genuinetools/binctr/container"
"github.com/opencontainers/runc/libcontainer"
_ "github.com/opencontainers/runc/libcontainer/nsenter"
"github.com/sirupsen/logrus"
)
const (
defaultRoot = "/tmp/binctr-busybox"
defaultRootfsDir = "rootfs"
)
var (
containerID string
root string
)
func init() {
// Parse flags
flag.StringVar(&containerID, "id", "busybox", "container ID")
flag.StringVar(&root, "root", defaultRoot, "root directory of container state, should be tmpfs")
flag.Usage = func() {
flag.PrintDefaults()
}
flag.Parse()
}
//go:generate go run generate.go
func main() {
if len(os.Args) > 1 && os.Args[1] == "init" {
runInit()
return
}
// Create a new container spec with the following options.
opts := container.SpecOpts{
Rootless: true,
Terminal: true,
}
spec := container.Spec(opts)
// Initialize the container object.
c := &container.Container{
ID: containerID,
Spec: spec,
Root: root,
Rootless: true,
}
// Unpack the rootfs.
if err := c.UnpackRootfs(defaultRootfsDir, Asset); err != nil {
logrus.Fatal(err)
}
// Run the container.
status, err := c.Run()
if err != nil {
logrus.Fatal(err)
}
// Remove the rootfs after the container has exited.
if err := os.RemoveAll(defaultRootfsDir); err != nil {
logrus.Warnf("removing rootfs failed: %v", err)
}
// Exit with the container's exit status.
os.Exit(status)
}
func runInit() {
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")
}