package libcontainerd import ( "fmt" "io" "os" "path/filepath" "syscall" containerd "github.com/docker/containerd/api/grpc/types" "github.com/docker/docker/pkg/ioutils" "golang.org/x/net/context" ) var fdNames = map[int]string{ syscall.Stdin: "stdin", syscall.Stdout: "stdout", syscall.Stderr: "stderr", } // process keeps the state for both main container process and exec process. type process struct { processCommon // Platform specific fields are below here. dir string } func (p *process) openFifos(terminal bool) (*IOPipe, error) { bundleDir := p.dir if err := os.MkdirAll(bundleDir, 0700); err != nil { return nil, err } for i := 0; i < 3; i++ { f := p.fifo(i) if err := syscall.Mkfifo(f, 0700); err != nil && !os.IsExist(err) { return nil, fmt.Errorf("mkfifo: %s %v", f, err) } } io := &IOPipe{} stdinf, err := os.OpenFile(p.fifo(syscall.Stdin), syscall.O_RDWR, 0) if err != nil { return nil, err } io.Stdout = openReaderFromFifo(p.fifo(syscall.Stdout)) if !terminal { io.Stderr = openReaderFromFifo(p.fifo(syscall.Stderr)) } else { io.Stderr = emptyReader{} } io.Stdin = ioutils.NewWriteCloserWrapper(stdinf, func() error { stdinf.Close() _, err := p.client.remote.apiClient.UpdateProcess(context.Background(), &containerd.UpdateProcessRequest{ Id: p.containerID, Pid: p.friendlyName, CloseStdin: true, }) return err }) return io, nil } func (p *process) closeFifos(io *IOPipe) { io.Stdin.Close() closeReaderFifo(p.fifo(syscall.Stdout)) closeReaderFifo(p.fifo(syscall.Stderr)) } type emptyReader struct{} func (r emptyReader) Read(b []byte) (int, error) { return 0, io.EOF } func openReaderFromFifo(fn string) io.Reader { r, w := io.Pipe() go func() { stdoutf, err := os.OpenFile(fn, syscall.O_RDONLY, 0) if err != nil { r.CloseWithError(err) } if _, err := io.Copy(w, stdoutf); err != nil { r.CloseWithError(err) } w.Close() stdoutf.Close() }() return r } // closeReaderFifo closes fifo that may be blocked on open by opening the write side. func closeReaderFifo(fn string) { f, err := os.OpenFile(fn, syscall.O_WRONLY|syscall.O_NONBLOCK, 0) if err != nil { return } f.Close() } func (p *process) fifo(index int) string { return filepath.Join(p.dir, p.friendlyName+"-"+fdNames[index]) }