From a59f1db48bedd3b72a58e4d5193eb17c413aa4d0 Mon Sep 17 00:00:00 2001
From: Nir Soffer <nsoffer@redhat.com>
Date: Feb 26 2018 19:08:58 +0000
Subject: Show stderr when sanlock command fail


When util.sanlock() fail, we show now also the command stderr, allowing
assertions about sanlock behavior, and easier debugging.

Signed-off-by: Nir Soffer <nsoffer@redhat.com>

---

diff --git a/tests/daemon_test.py b/tests/daemon_test.py
index 9697658..84afacb 100644
--- a/tests/daemon_test.py
+++ b/tests/daemon_test.py
@@ -5,7 +5,6 @@ Test sanlock client operations.
 import io
 import signal
 import struct
-import subprocess
 
 import pytest
 
@@ -38,7 +37,7 @@ def test_start_after_kill():
 
 def test_client_failure():
     # No daemon is running, client must fail
-    with pytest.raises(subprocess.CalledProcessError) as e:
+    with pytest.raises(util.CommandError) as e:
         util.sanlock("client", "status")
     assert e.value.returncode == 1
 
diff --git a/tests/util.py b/tests/util.py
index 157624a..9bd35fb 100644
--- a/tests/util.py
+++ b/tests/util.py
@@ -16,6 +16,20 @@ class TimeoutExpired(Exception):
     """ Raised when timeout expired """
 
 
+class CommandError(Exception):
+    msg = ("Command {self.cmd} failed with returncode={self.returncode}, "
+           "stdout={self.stdout!r}, stderr={self.stderr!r}")
+
+    def __init__(self, cmd, returncode, stdout, stderr):
+        self.cmd = cmd
+        self.returncode = returncode
+        self.stdout = stdout
+        self.stderr = stderr
+
+    def __str__(self):
+        return self.msg.format(self=self)
+
+
 def start_daemon():
     cmd = [SANLOCK, "daemon",
            # no fork and print all logging to stderr
@@ -57,11 +71,15 @@ def wait_for_daemon(timeout):
 def sanlock(*args):
     """
     Run sanlock returning the process stdout, or raising
-    subprocess.CalledProcessError on failures.
+    util.CommandError on failures.
     """
     cmd = [SANLOCK]
     cmd.extend(args)
-    return subprocess.check_output(cmd)
+    p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    out, err = p.communicate()
+    if p.returncode:
+        raise CommandError(cmd, p.returncode, out, err)
+    return out
 
 
 def wait_for_termination(p, timeout):