Add podman container cleanup to CLI

When we run containers in detach mode, nothing cleans up the network stack or
the mount points.  This patch will tell conmon to execute the cleanup code when
the container exits.

It can also be called to attempt to cleanup previously running containers.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

Closes: #942
Approved by: mheon

libpod/container.go

@@ -314,6 +314,10 @@ type ContainerConfig struct {
 	// TODO log options for log drivers
 
 	PostConfigureNetNS bool `json:"postConfigureNetNS"`
+
+	// ExitCommand is the container's exit command.
+	// This Command will be executed when the container exits
+	ExitCommand []string `json:"exitCommand,omitempty"`
 }
 
 // ContainerStatus returns a string representation for users

libpod/container_inspect.go

@@ -71,6 +71,7 @@ func (c *Container) getContainerInspectData(size bool, driverData *inspect.Data)
 		},
 		ImageID:         config.RootfsImageID,
 		ImageName:       config.RootfsImageName,
+		ExitCommand:     config.ExitCommand,
 		Rootfs:          config.Rootfs,
 		ResolvConfPath:  resolvPath,
 		HostnamePath:    hostnamePath,

libpod/container_internal.go

@@ -695,7 +695,8 @@ func (c *Container) stop(timeout uint) error {
 		return err
 	}
 
-	return c.cleanup()
+	// Container should clean itself up
+	return nil
 }
 
 // Internal, non-locking function to pause a container
@@ -928,11 +929,17 @@ func (c *Container) cleanup() error {
 	}
 
 	if err := c.cleanupCgroups(); err != nil {
-		if lastError != nil {
-			logrus.Errorf("Error cleaning up container %s CGroups: %v", c.ID(), err)
-		} else {
-			lastError = err
-		}
+		/*
+			if lastError != nil {
+				logrus.Errorf("Error cleaning up container %s CGroups: %v", c.ID(), err)
+			} else {
+				lastError = err
+			}
+		*/
+		// For now we are going to only warn on failures to clean up cgroups
+		// We have a conflict with running podman containers cleanup in same cgroup as container
+		logrus.Warnf("Ignoring Error cleaning up container %s CGroups: %v", c.ID(), err)
+
 	}
 
 	// Unmount storage

libpod/oci.go

@@ -268,6 +268,12 @@ func (r *OCIRuntime) createOCIContainer(ctr *Container, cgroupParent string) (er
 	if ctr.config.ConmonPidFile != "" {
 		args = append(args, "--conmon-pidfile", ctr.config.ConmonPidFile)
 	}
+	if len(ctr.config.ExitCommand) > 0 {
+		args = append(args, "--exit-command", ctr.config.ExitCommand[0])
+		for _, arg := range ctr.config.ExitCommand[1:] {
+			args = append(args, []string{"--exit-command-arg", arg}...)
+		}
+	}
 	args = append(args, "--socket-dir-path", r.socketsDir)
 	if ctr.config.Spec.Process.Terminal {
 		args = append(args, "-t")

libpod/options.go

@@ -485,6 +485,18 @@ func WithIDMappings(idmappings storage.IDMappingOptions) CtrCreateOption {
 	}
 }
 
+// WithExitCommand sets the ExitCommand for the container, appending on the ctr.ID() to the end
+func WithExitCommand(exitCommand []string) CtrCreateOption {
+	return func(ctr *Container) error {
+		if ctr.valid {
+			return ErrCtrFinalized
+		}
+
+		ctr.config.ExitCommand = append(exitCommand, ctr.ID())
+		return nil
+	}
+}
+
 // WithIPCNSFrom indicates the the container should join the IPC namespace of
 // the given container.
 // If the container has joined a pod, it can only join the namespaces of