Merge pull request #10405 from mheon/always_cleanup_exec

Always spawn a cleanup process with exec

4 files changed, 85 insertions, 25 deletions

diff --git a/libpod/container_exec.go b/libpod/container_exec.go
index c359f1e5d..737bf74ad 100644
--- a/libpod/container_exec.go
+++ b/libpod/container_exec.go
@@ -1,6 +1,7 @@
 package libpod
 
 import (
+	"context"
 	"io/ioutil"
 	"net/http"
 	"os"
@@ -539,18 +540,7 @@ func (c *Container) ExecStop(sessionID string, timeout *uint) error {
 	var cleanupErr error
 
 	// Retrieve exit code and update status
-	exitCode, err := c.readExecExitCode(session.ID())
-	if err != nil {
-		cleanupErr = err
-	}
-	session.ExitCode = exitCode
-	session.PID = 0
-	session.State = define.ExecStateStopped
-
-	if err := c.save(); err != nil {
-		if cleanupErr != nil {
-			logrus.Errorf("Error stopping container %s exec session %s: %v", c.ID(), session.ID(), cleanupErr)
-		}
+	if err := retrieveAndWriteExecExitCode(c, session.ID()); err != nil {
 		cleanupErr = err
 	}
 
@@ -592,15 +582,7 @@ func (c *Container) ExecCleanup(sessionID string) error {
 			return errors.Wrapf(define.ErrExecSessionStateInvalid, "cannot clean up container %s exec session %s as it is running", c.ID(), session.ID())
 		}
 
-		exitCode, err := c.readExecExitCode(session.ID())
-		if err != nil {
-			return err
-		}
-		session.ExitCode = exitCode
-		session.PID = 0
-		session.State = define.ExecStateStopped
-
-		if err := c.save(); err != nil {
+		if err := retrieveAndWriteExecExitCode(c, session.ID()); err != nil {
 			return err
 		}
 	}
@@ -637,9 +619,9 @@ func (c *Container) ExecRemove(sessionID string, force bool) error {
 			return err
 		}
 		if !running {
-			session.State = define.ExecStateStopped
-			// TODO: should we retrieve exit code here?
-			// TODO: Might be worth saving state here.
+			if err := retrieveAndWriteExecExitCode(c, session.ID()); err != nil {
+				return err
+			}
 		}
 	}
 
@@ -653,6 +635,10 @@ func (c *Container) ExecRemove(sessionID string, force bool) error {
 			return err
 		}
 
+		if err := retrieveAndWriteExecExitCode(c, session.ID()); err != nil {
+			return err
+		}
+
 		if err := c.cleanupExecBundle(session.ID()); err != nil {
 			return err
 		}
@@ -757,10 +743,25 @@ func (c *Container) Exec(config *ExecConfig, streams *define.AttachStreams, resi
 
 	session, err := c.ExecSession(sessionID)
 	if err != nil {
+		if errors.Cause(err) == define.ErrNoSuchExecSession {
+			// TODO: If a proper Context is ever plumbed in here, we
+			// should use it.
+			// As things stand, though, it's not worth it - this
+			// should always terminate quickly since it's not
+			// streaming.
+			diedEvent, err := c.runtime.GetExecDiedEvent(context.Background(), c.ID(), sessionID)
+			if err != nil {
+				return -1, errors.Wrapf(err, "error retrieving exec session %s exit code", sessionID)
+			}
+			return diedEvent.ContainerExitCode, nil
+		}
 		return -1, err
 	}
 	exitCode := session.ExitCode
 	if err := c.ExecRemove(sessionID, false); err != nil {
+		if errors.Cause(err) == define.ErrNoSuchExecSession {
+			return exitCode, nil
+		}
 		return -1, err
 	}
 
@@ -927,6 +928,8 @@ func (c *Container) getActiveExecSessions() ([]string, error) {
 				session.PID = 0
 				session.State = define.ExecStateStopped
 
+				c.newExecDiedEvent(session.ID(), exitCode)
+
 				needSave = true
 			}
 			if err := c.cleanupExecBundle(id); err != nil {
@@ -1036,6 +1039,22 @@ func writeExecExitCode(c *Container, sessionID string, exitCode int) error {
 		return errors.Wrapf(err, "error syncing container %s state to remove exec session %s", c.ID(), sessionID)
 	}
 
+	return justWriteExecExitCode(c, sessionID, exitCode)
+}
+
+func retrieveAndWriteExecExitCode(c *Container, sessionID string) error {
+	exitCode, err := c.readExecExitCode(sessionID)
+	if err != nil {
+		return err
+	}
+
+	return justWriteExecExitCode(c, sessionID, exitCode)
+}
+
+func justWriteExecExitCode(c *Container, sessionID string, exitCode int) error {
+	// Write an event first
+	c.newExecDiedEvent(sessionID, exitCode)
+
 	session, ok := c.state.ExecSessions[sessionID]
 	if !ok {
 		// Exec session already removed.
diff --git a/libpod/events.go b/libpod/events.go
index 839229674..22c51aeec 100644
--- a/libpod/events.go
+++ b/libpod/events.go
@@ -46,7 +46,22 @@ func (c *Container) newContainerExitedEvent(exitCode int32) {
 	e.Type = events.Container
 	e.ContainerExitCode = int(exitCode)
 	if err := c.runtime.eventer.Write(e); err != nil {
-		logrus.Errorf("unable to write pod event: %q", err)
+		logrus.Errorf("unable to write container exited event: %q", err)
+	}
+}
+
+// newExecDiedEvent creates a new event for an exec session's death
+func (c *Container) newExecDiedEvent(sessionID string, exitCode int) {
+	e := events.NewEvent(events.ExecDied)
+	e.ID = c.ID()
+	e.Name = c.Name()
+	e.Image = c.config.RootfsImageName
+	e.Type = events.Container
+	e.ContainerExitCode = exitCode
+	e.Attributes = make(map[string]string)
+	e.Attributes["execID"] = sessionID
+	if err := c.runtime.eventer.Write(e); err != nil {
+		logrus.Errorf("unable to write exec died event: %q", err)
 	}
 }
 
@@ -154,3 +169,25 @@ func (r *Runtime) GetLastContainerEvent(ctx context.Context, nameOrID string, co
 	// return the last element in the slice
 	return containerEvents[len(containerEvents)-1], nil
 }
+
+// GetExecDiedEvent takes a container name or ID, exec session ID, and returns
+// that exec session's Died event (if it has already occurred).
+func (r *Runtime) GetExecDiedEvent(ctx context.Context, nameOrID, execSessionID string) (*events.Event, error) {
+	filters := []string{
+		fmt.Sprintf("container=%s", nameOrID),
+		"event=exec_died",
+		"type=container",
+		fmt.Sprintf("label=execID=%s", execSessionID),
+	}
+
+	containerEvents, err := r.GetEvents(ctx, filters)
+	if err != nil {
+		return nil, err
+	}
+	// There *should* only be one event maximum.
+	// But... just in case... let's not blow up if there's more than one.
+	if len(containerEvents) < 1 {
+		return nil, errors.Wrapf(events.ErrEventNotFound, "exec died event for session %s (container %s) not found", execSessionID, nameOrID)
+	}
+	return containerEvents[len(containerEvents)-1], nil
+}
diff --git a/libpod/events/config.go b/libpod/events/config.go
index 085fa9d52..d88d7b6e3 100644
--- a/libpod/events/config.go
+++ b/libpod/events/config.go
@@ -127,6 +127,8 @@ const (
 	Create Status = "create"
 	// Exec ...
 	Exec Status = "exec"
+	// ExecDied indicates that an exec session in a container died.
+	ExecDied Status = "exec_died"
 	// Exited indicates that a container's process died
 	Exited Status = "died"
 	// Export ...
diff --git a/libpod/events/events.go b/libpod/events/events.go
index 01ea6a386..e03215eff 100644
--- a/libpod/events/events.go
+++ b/libpod/events/events.go
@@ -149,6 +149,8 @@ func StringToStatus(name string) (Status, error) {
 		return Create, nil
 	case Exec.String():
 		return Exec, nil
+	case ExecDied.String():
+		return ExecDied, nil
 	case Exited.String():
 		return Exited, nil
 	case Export.String():