container, cgroup: detect pid termination

If the /proc/$PID/cgroup file doesn't exist, then it is likely the container was terminated in the meanwhile so report ErrCtrStopped that is already handled instead of ENOENT. commit a66f40b introduced the regression. Closes: containers#12457 [NO NEW TESTS NEEDED] it solves a race in the CI that is difficult to reproduce. Signed-off-by: Giuseppe Scrivano <[email protected]>
giuseppe · Dec 1, 2021 · 0afaf78 · 0afaf78
1 parent 295a6f7
commit 0afaf78
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/libpod/container.go b/libpod/container.go
@@ -939,6 +939,11 @@ func (c *Container) cGroupPath() (string, error) {
 	procPath := fmt.Sprintf("/proc/%d/cgroup", c.state.PID)
 	lines, err := ioutil.ReadFile(procPath)
 	if err != nil {
+		// If the file doesn't exist, it means the container could have been terminated
+		// so report it.
+		if os.IsNotExist(err) {
+			return "", errors.Wrapf(define.ErrCtrStopped, "cannot get cgroup path unless container %s is running", c.ID())
+		}
 		return "", err
 	}