add _zypper_check_result() to raise and error or return stdout

salt/modules/zypper.py

@@ -26,6 +26,7 @@ except ImportError:
 # pylint: enable=import-error,redefined-builtin,no-name-in-module
 
 from xml.dom import minidom as dom
+from xml.parsers.expat import ExpatError
 
 # Import salt libs
 import salt.utils
@@ -79,6 +80,44 @@ def _is_zypper_error(retcode):
     return not int(retcode) in [0, 100, 101, 102, 103]
 
 
+def _zypper_check_result(result, xml=False):
+    '''
+    Check the result of a zypper command. In case of an error, it raise
+    a CommandExecutionError. Otherwise it returns stdout string of the
+    command.
+
+    result
+        The result of a zypper command called with cmd.run_all
+
+    xml
+        Set to True if zypper command was called with --xmlout.
+        In this case it try to read an error message out of the XML
+        stream. Default is False.
+    '''
+    if _is_zypper_error(result['retcode']):
+        msg = list()
+        if not xml:
+            msg.append(result['stderr'] and result['stderr'] or "")
+        else:
+            try:
+                doc = dom.parseString(result['stdout'])
+            except ExpatError as err:
+                log.error(err)
+                doc = None
+            if doc:
+                msg_nodes = doc.getElementsByTagName('message')
+                for node in msg_nodes:
+                    if node.getAttribute('type') == 'error':
+                        msg.append(node.childNodes[0].nodeValue)
+            elif result['stderr'].strip():
+                msg.append(result['stderr'].strip())
+
+        raise CommandExecutionError("zypper command failed: {0}".format(
+            msg and os.linesep.join(msg) or "Check zypper logs"))
+
+    return result['stdout']
+
+
 def list_upgrades(refresh=True):
     '''
     List all available package upgrades on this system