Move Server.ContainerAttach to Daemon.ContainerAttach

This is part of an effort to break apart the legacy server package. Help wanted!

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)

builder/builder.go

@@ -683,6 +683,11 @@ func (b *buildFile) run(c *daemon.Container) error {
 	var errCh chan error
 	if b.verbose {
 		errCh = utils.Go(func() error {
+			// FIXME: call the 'attach' job so that daemon.Attach can be made private
+			//
+			// FIXME (LK4D4): Also, maybe makes sense to call "logs" job, it is like attach
+			// but without hijacking for stdin. Also, with attach there can be race
+			// condition because of some output already was printed before it.
 			return <-b.daemon.Attach(c, nil, nil, b.outStream, b.errStream)
 		})
 	}

daemon/attach.go

@@ -1,11 +1,122 @@
 package daemon
 
 import (
+	"encoding/json"
+	"fmt"
 	"io"
+	"os"
+	"time"
 
+	"github.com/docker/docker/engine"
 	"github.com/docker/docker/utils"
 )
 
+func (daemon *Daemon) ContainerAttach(job *engine.Job) engine.Status {
+	if len(job.Args) != 1 {
+		return job.Errorf("Usage: %s CONTAINER\n", job.Name)
+	}
+
+	var (
+		name   = job.Args[0]
+		logs   = job.GetenvBool("logs")
+		stream = job.GetenvBool("stream")
+		stdin  = job.GetenvBool("stdin")
+		stdout = job.GetenvBool("stdout")
+		stderr = job.GetenvBool("stderr")
+	)
+
+	container := daemon.Get(name)
+	if container == nil {
+		return job.Errorf("No such container: %s", name)
+	}
+
+	//logs
+	if logs {
+		cLog, err := container.ReadLog("json")
+		if err != nil && os.IsNotExist(err) {
+			// Legacy logs
+			utils.Debugf("Old logs format")
+			if stdout {
+				cLog, err := container.ReadLog("stdout")
+				if err != nil {
+					utils.Errorf("Error reading logs (stdout): %s", err)
+				} else if _, err := io.Copy(job.Stdout, cLog); err != nil {
+					utils.Errorf("Error streaming logs (stdout): %s", err)
+				}
+			}
+			if stderr {
+				cLog, err := container.ReadLog("stderr")
+				if err != nil {
+					utils.Errorf("Error reading logs (stderr): %s", err)
+				} else if _, err := io.Copy(job.Stderr, cLog); err != nil {
+					utils.Errorf("Error streaming logs (stderr): %s", err)
+				}
+			}
+		} else if err != nil {
+			utils.Errorf("Error reading logs (json): %s", err)
+		} else {
+			dec := json.NewDecoder(cLog)
+			for {
+				l := &utils.JSONLog{}
+
+				if err := dec.Decode(l); err == io.EOF {
+					break
+				} else if err != nil {
+					utils.Errorf("Error streaming logs: %s", err)
+					break
+				}
+				if l.Stream == "stdout" && stdout {
+					fmt.Fprintf(job.Stdout, "%s", l.Log)
+				}
+				if l.Stream == "stderr" && stderr {
+					fmt.Fprintf(job.Stderr, "%s", l.Log)
+				}
+			}
+		}
+	}
+
+	//stream
+	if stream {
+		var (
+			cStdin           io.ReadCloser
+			cStdout, cStderr io.Writer
+			cStdinCloser     io.Closer
+		)
+
+		if stdin {
+			r, w := io.Pipe()
+			go func() {
+				defer w.Close()
+				defer utils.Debugf("Closing buffered stdin pipe")
+				io.Copy(w, job.Stdin)
+			}()
+			cStdin = r
+			cStdinCloser = job.Stdin
+		}
+		if stdout {
+			cStdout = job.Stdout
+		}
+		if stderr {
+			cStderr = job.Stderr
+		}
+
+		<-daemon.Attach(container, cStdin, cStdinCloser, cStdout, cStderr)
+
+		// If we are in stdinonce mode, wait for the process to end
+		// otherwise, simply return
+		if container.Config.StdinOnce && !container.Config.Tty {
+			container.State.WaitStop(-1 * time.Second)
+		}
+	}
+	return engine.StatusOK
+}
+
+// FIXME: this should be private, and every outside subsystem
+// should go through the "container_attach" job. But that would require
+// that job to be properly documented, as well as the relationship betweem
+// Attach and ContainerAttach.
+//
+// This method is in use by builder/builder.go.
 func (daemon *Daemon) Attach(container *Container, stdin io.ReadCloser, stdinCloser io.Closer, stdout io.Writer, stderr io.Writer) chan error {
 	var (
 		cStdout, cStderr io.ReadCloser

daemon/daemon.go

@@ -105,7 +105,13 @@ type Daemon struct {
 
 // Install installs daemon capabilities to eng.
 func (daemon *Daemon) Install(eng *engine.Engine) error {
-	return eng.Register("container_inspect", daemon.ContainerInspect)
+	if err := eng.Register("container_inspect", daemon.ContainerInspect); err != nil {
+		return err
+	}
+	if err := eng.Register("attach", daemon.ContainerAttach); err != nil {
+		return err
+	}
+	return nil
 }
 
 // List returns an array of all containers registered in the daemon.

server/container.go

@@ -798,105 +798,6 @@ func (srv *Server) ContainerLogs(job *engine.Job) engine.Status {
 	return engine.StatusOK
 }
 
-func (srv *Server) ContainerAttach(job *engine.Job) engine.Status {
-	if len(job.Args) != 1 {
-		return job.Errorf("Usage: %s CONTAINER\n", job.Name)
-	}
-
-	var (
-		name   = job.Args[0]
-		logs   = job.GetenvBool("logs")
-		stream = job.GetenvBool("stream")
-		stdin  = job.GetenvBool("stdin")
-		stdout = job.GetenvBool("stdout")
-		stderr = job.GetenvBool("stderr")
-	)
-
-	container := srv.daemon.Get(name)
-	if container == nil {
-		return job.Errorf("No such container: %s", name)
-	}
-
-	//logs
-	if logs {
-		cLog, err := container.ReadLog("json")
-		if err != nil && os.IsNotExist(err) {
-			// Legacy logs
-			utils.Debugf("Old logs format")
-			if stdout {
-				cLog, err := container.ReadLog("stdout")
-				if err != nil {
-					utils.Errorf("Error reading logs (stdout): %s", err)
-				} else if _, err := io.Copy(job.Stdout, cLog); err != nil {
-					utils.Errorf("Error streaming logs (stdout): %s", err)
-				}
-			}
-			if stderr {
-				cLog, err := container.ReadLog("stderr")
-				if err != nil {
-					utils.Errorf("Error reading logs (stderr): %s", err)
-				} else if _, err := io.Copy(job.Stderr, cLog); err != nil {
-					utils.Errorf("Error streaming logs (stderr): %s", err)
-				}
-			}
-		} else if err != nil {
-			utils.Errorf("Error reading logs (json): %s", err)
-		} else {
-			dec := json.NewDecoder(cLog)
-			for {
-				l := &utils.JSONLog{}
-
-				if err := dec.Decode(l); err == io.EOF {
-					break
-				} else if err != nil {
-					utils.Errorf("Error streaming logs: %s", err)
-					break
-				}
-				if l.Stream == "stdout" && stdout {
-					fmt.Fprintf(job.Stdout, "%s", l.Log)
-				}
-				if l.Stream == "stderr" && stderr {
-					fmt.Fprintf(job.Stderr, "%s", l.Log)
-				}
-			}
-		}
-	}
-
-	//stream
-	if stream {
-		var (
-			cStdin           io.ReadCloser
-			cStdout, cStderr io.Writer
-			cStdinCloser     io.Closer
-		)
-
-		if stdin {
-			r, w := io.Pipe()
-			go func() {
-				defer w.Close()
-				defer utils.Debugf("Closing buffered stdin pipe")
-				io.Copy(w, job.Stdin)
-			}()
-			cStdin = r
-			cStdinCloser = job.Stdin
-		}
-		if stdout {
-			cStdout = job.Stdout
-		}
-		if stderr {
-			cStderr = job.Stderr
-		}
-
-		<-srv.daemon.Attach(container, cStdin, cStdinCloser, cStdout, cStderr)
-
-		// If we are in stdinonce mode, wait for the process to end
-		// otherwise, simply return
-		if container.Config.StdinOnce && !container.Config.Tty {
-			container.State.WaitStop(-1 * time.Second)
-		}
-	}
-	return engine.StatusOK
-}
 
 func (srv *Server) ContainerCopy(job *engine.Job) engine.Status {
 	if len(job.Args) != 2 {

server/init.go

@@ -105,7 +105,6 @@ func InitServer(job *engine.Job) engine.Status {
 		"history":          srv.ImageHistory,
 		"viz":              srv.ImagesViz,
 		"container_copy":   srv.ContainerCopy,
-		"attach":           srv.ContainerAttach,
 		"logs":             srv.ContainerLogs,
 		"changes":          srv.ContainerChanges,
 		"top":              srv.ContainerTop,