Add a MissingRuntime implementation

When a container is created with a given OCI runtime, but then it
is uninstalled or removed from the configuration file, Libpod
presently reacts very poorly. The EvictContainer code can
potentially remove these containers, but we still can't see them
in `podman ps` (aside from the massive logrus.Errorf messages
they create).

Providing a minimal OCI runtime implementation for missing
runtimes allows us to behave better. We'll be able to retrieve
containers from the database, though we still pop up an error for
each missing runtime. For containers which are stopped, we can
remove them as normal.

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

1 files changed, 36 insertions, 3 deletions

diff --git a/libpod/container_internal.go b/libpod/container_internal.go
index a7ac23f73..0043c9651 100644
--- a/libpod/container_internal.go
+++ b/libpod/container_internal.go
@@ -252,7 +252,7 @@ func (c *Container) waitForExitFileAndSync() error {
 		return err
 	}
 
-	if err := c.ociRuntime.UpdateContainerStatus(c, false); err != nil {
+	if err := c.checkExitFile(); err != nil {
 		return err
 	}
 
@@ -386,10 +386,11 @@ func (c *Container) syncContainer() error {
 		(c.state.State != define.ContainerStateConfigured) &&
 		(c.state.State != define.ContainerStateExited) {
 		oldState := c.state.State
-		// TODO: optionally replace this with a stat for the exit file
-		if err := c.ociRuntime.UpdateContainerStatus(c, false); err != nil {
+
+		if err := c.checkExitFile(); err != nil {
 			return err
 		}
+
 		// Only save back to DB if state changed
 		if c.state.State != oldState {
 			// Check for a restart policy match
@@ -1811,3 +1812,35 @@ func (c *Container) sortUserVolumes(ctrSpec *spec.Spec) ([]*ContainerNamedVolume
 	}
 	return namedUserVolumes, userMounts
 }
+
+// Check for an exit file, and handle one if present
+func (c *Container) checkExitFile() error {
+	// If the container's not running, nothing to do.
+	if c.state.State != define.ContainerStateRunning && c.state.State != define.ContainerStatePaused {
+		return nil
+	}
+
+	exitFile, err := c.exitFilePath()
+	if err != nil {
+		return err
+	}
+
+	// Check for the exit file
+	info, err := os.Stat(exitFile)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// Container is still running, no error
+			return nil
+		}
+
+		return errors.Wrapf(err, "error running stat on container %s exit file", c.ID())
+	}
+
+	// Alright, it exists. Transition to Stopped state.
+	c.state.State = define.ContainerStateStopped
+	c.state.PID = 0
+	c.state.ConmonPID = 0
+
+	// Read the exit file to get our stopped time and exit code.
+	return c.handleExitFile(exitFile, info)
+}