Enable cleanup processes for detached exec

The cleanup command creation logic is made public as part of this
and wired such that we can call it both within SpecGen (to make
container exit commands) and from the ABI detached exec handler.
Exit commands are presently only used for detached exec, but
theoretically could be turned on for all exec sessions if we
wanted (I'm declining to do this because of potential overhead).

I also forgot to copy the exit command from the exec config into
the ExecOptions struct used by the OCI runtime, so it was not
being added.

There are also two significant bugfixes for exec in here. One is
for updating the status of running exec sessions - this was
always failing as I had coded it to remove the exit file *before*
reading it, instead of after (oops). The second was that removing
a running exec session would always fail because I inverted the
check to see if it was running.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

2 files changed, 20 insertions, 9 deletions

diff --git a/libpod/container_exec.go b/libpod/container_exec.go
index efbd49b15..f2943b73c 100644
--- a/libpod/container_exec.go
+++ b/libpod/container_exec.go
@@ -65,6 +65,9 @@ type ExecConfig struct {
 	// ExitCommand is the exec session's exit command.
 	// This command will be executed when the exec session exits.
 	// If unset, no command will be executed.
+	// Two arguments will be appended to the exit command by Libpod:
+	// The ID of the exec session, and the ID of the container the exec
+	// session is a part of (in that order).
 	ExitCommand []string `json:"exitCommand,omitempty"`
 }
 
@@ -195,6 +198,10 @@ func (c *Container) ExecCreate(config *ExecConfig) (string, error) {
 		return "", errors.Wrapf(err, "error copying exec configuration into exec session")
 	}
 
+	if len(session.Config.ExitCommand) > 0 {
+		session.Config.ExitCommand = append(session.Config.ExitCommand, []string{session.ID(), c.ID()}...)
+	}
+
 	if c.state.ExecSessions == nil {
 		c.state.ExecSessions = make(map[string]*ExecSession)
 	}
@@ -606,11 +613,11 @@ func (c *Container) ExecRemove(sessionID string, force bool) error {
 	// Update status of exec session if running, so we cna check if it
 	// stopped in the meantime.
 	if session.State == define.ExecStateRunning {
-		stopped, err := c.ociRuntime.ExecUpdateStatus(c, session.ID())
+		running, err := c.ociRuntime.ExecUpdateStatus(c, session.ID())
 		if err != nil {
 			return err
 		}
-		if stopped {
+		if !running {
 			session.State = define.ExecStateStopped
 			// TODO: should we retrieve exit code here?
 			// TODO: Might be worth saving state here.
@@ -865,13 +872,6 @@ func (c *Container) getActiveExecSessions() ([]string, error) {
 			continue
 		}
 		if !alive {
-			if err := c.cleanupExecBundle(id); err != nil {
-				if lastErr != nil {
-					logrus.Errorf("Error checking container %s exec sessions: %v", c.ID(), lastErr)
-				}
-				lastErr = err
-			}
-
 			_, isLegacy := c.state.LegacyExecSessions[id]
 			if isLegacy {
 				delete(c.state.LegacyExecSessions, id)
@@ -891,6 +891,12 @@ func (c *Container) getActiveExecSessions() ([]string, error) {
 
 				needSave = true
 			}
+			if err := c.cleanupExecBundle(id); err != nil {
+				if lastErr != nil {
+					logrus.Errorf("Error checking container %s exec sessions: %v", c.ID(), lastErr)
+				}
+				lastErr = err
+			}
 		} else {
 			activeSessions = append(activeSessions, id)
 		}
@@ -911,6 +917,8 @@ func (c *Container) getActiveExecSessions() ([]string, error) {
 func (c *Container) removeAllExecSessions() error {
 	knownSessions := c.getKnownExecSessions()
 
+	logrus.Debugf("Removing all exec sessions for container %s", c.ID())
+
 	var lastErr error
 	for _, id := range knownSessions {
 		if err := c.ociRuntime.ExecStopContainer(c, id, c.StopTimeout()); err != nil {
@@ -975,6 +983,7 @@ func prepareForExec(c *Container, session *ExecSession) (*ExecOptions, error) {
 	opts.User = user
 	opts.PreserveFDs = session.Config.PreserveFDs
 	opts.DetachKeys = session.Config.DetachKeys
+	opts.ExitCommand = session.Config.ExitCommand
 
 	return opts, nil
 }
diff --git a/libpod/runtime_ctr.go b/libpod/runtime_ctr.go
index c670822a0..655b42e51 100644
--- a/libpod/runtime_ctr.go
+++ b/libpod/runtime_ctr.go
@@ -390,6 +390,8 @@ func (r *Runtime) removeContainer(ctx context.Context, c *Container, force bool,
 		}
 	}
 
+	logrus.Debugf("Removing container %s", c.ID())
+
 	// We need to lock the pod before we lock the container.
 	// To avoid races around removing a container and the pod it is in.
 	// Don't need to do this in pod removal case - we're evicting the entire