package linux import ( "fmt" "io/ioutil" "log" "net" "os/exec" "path/filepath" "syscall" "time" "google.golang.org/grpc" "google.golang.org/grpc/grpclog" "github.com/docker/containerd/api/services/shim" "github.com/docker/containerd/utils" "github.com/pkg/errors" ) func newShim(path string) (shim.ShimClient, error) { socket := filepath.Join(path, "shim.sock") l, err := utils.CreateUnixSocket(socket) if err != nil { return nil, err } cmd := exec.Command("containerd-shim") cmd.Dir = path f, err := l.(*net.UnixListener).File() if err != nil { return nil, err } cmd.ExtraFiles = append(cmd.ExtraFiles, f) // make sure the shim can be re-parented to system init // and is cloned in a new mount namespace because the overlay/filesystems // will be mounted by the shim cmd.SysProcAttr = &syscall.SysProcAttr{ Cloneflags: syscall.CLONE_NEWNS, Setpgid: true, } if err := cmd.Start(); err != nil { return nil, errors.Wrapf(err, "failed to start shim") } // close our side of the socket, do not close the listener as it will // remove the socket from disk f.Close() // since we are currently the parent go ahead and make sure we wait on the shim go cmd.Wait() return connectShim(socket) } func loadShim(path string) (shim.ShimClient, error) { socket := filepath.Join(path, "shim.sock") return connectShim(socket) // TODO: failed to connect to the shim, check if it's alive // - if it is kill it // - in both case call runc killall and runc delete on the id } func connectShim(socket string) (shim.ShimClient, error) { // reset the logger for grpc to log to dev/null so that it does not mess with our stdio grpclog.SetLogger(log.New(ioutil.Discard, "", log.LstdFlags)) dialOpts := []grpc.DialOption{grpc.WithInsecure(), grpc.WithTimeout(100 * time.Second)} dialOpts = append(dialOpts, grpc.WithDialer(func(addr string, timeout time.Duration) (net.Conn, error) { return net.DialTimeout("unix", socket, timeout) }), grpc.WithBlock(), grpc.WithTimeout(2*time.Second), ) conn, err := grpc.Dial(fmt.Sprintf("unix://%s", socket), dialOpts...) if err != nil { return nil, errors.Wrapf(err, "failed to connect to shim via \"%s\"", fmt.Sprintf("unix://%s", socket)) } return shim.NewShimClient(conn), nil }