oci: print stderr only after checking state

when the "kill" command fails, print the stderr from the OCI runtime
only after we check the container state.

It also simplifies the code since we don't have to hard code the error
messages we want to ignore.

Closes: containers#18452

[NO NEW TESTS NEEDED] it fixes a flake.

Signed-off-by: Giuseppe Scrivano <[email protected]>

libpod/oci_conmon_common.go

@@ -420,22 +420,6 @@ func (r *ConmonOCIRuntime) StopContainer(ctr *Container, timeout uint, all bool)
 
 	killCtr := func(signal uint) (bool, error) {
 		stderr, err := r.killContainer(ctr, signal, all, true)
-
-		// Before handling error from KillContainer, convert STDERR to a []string
-		// (one string per line of output) and print it, ignoring known OCI runtime
-		// errors that we don't care about
-		stderrLines := strings.Split(stderr.String(), "\n")
-		for _, line := range stderrLines {
-			if line == "" {
-				continue
-			}
-			if strings.Contains(line, "container not running") || strings.Contains(line, "open pidfd: No such process") || strings.Contains(line, "kill container: No such process") {
-				logrus.Debugf("Failure to kill container (already stopped?): logged %s", line)
-				continue
-			}
-			fmt.Fprintf(os.Stderr, "%s\n", line)
-		}
-
 		if err != nil {
 			// There's an inherent race with the cleanup process (see
 			// #16142, #17142). If the container has already been marked as
@@ -461,6 +445,16 @@ func (r *ConmonOCIRuntime) StopContainer(ctr *Container, timeout uint, all bool)
 
 			return false, err
 		}
+
+		// Before handling error from KillContainer, convert STDERR to a []string
+		// (one string per line of output) and print it.
+		stderrLines := strings.Split(stderr.String(), "\n")
+		for _, line := range stderrLines {
+			if line != "" {
+				fmt.Fprintf(os.Stderr, "%s\n", line)
+			}
+		}
+
 		return false, nil
 	}