iotests: implement pretty-print for log and qmp_log

If iotests have lines exceeding >998 characters long, git doesn't
want to send it plaintext to the list. We can solve this by allowing
the iotests to use pretty printed QMP output that we can match against
instead.

As a bonus, it's much nicer for human eyes too.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-11-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index a96a7010d49439dbed8afa64170862188a2699cd..cbedfaf1df670ca29cf2838af370785d051142e6 100644 (file)
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -288,13 +288,18 @@ def filter_img_info(output, filename):
         lines.append(line)
     return '\n'.join(lines)
 
-def log(msg, filters=[]):
+def log(msg, filters=[], indent=None):
+    '''Logs either a string message or a JSON serializable message (like QMP).
+    If indent is provided, JSON serializable messages are pretty-printed.'''
     for flt in filters:
         msg = flt(msg)
     if isinstance(msg, dict) or isinstance(msg, list):
+        # Python < 3.4 needs to know not to add whitespace when pretty-printing:
+        separators = (', ', ': ') if indent is None else (',', ': ')
         # Don't sort if it's already sorted
         do_sort = not isinstance(msg, OrderedDict)
-        print(json.dumps(msg, sort_keys=do_sort))
+        print(json.dumps(msg, sort_keys=do_sort,
+                         indent=indent, separators=separators))
     else:
         print(msg)
 
@@ -483,14 +488,14 @@ class VM(qtest.QEMUQtestMachine):
             result.append(filter_qmp_event(ev))
         return result
 
-    def qmp_log(self, cmd, filters=[], **kwargs):
+    def qmp_log(self, cmd, filters=[], indent=None, **kwargs):
         full_cmd = OrderedDict((
             ("execute", cmd),
             ("arguments", ordered_kwargs(kwargs))
         ))
-        log(full_cmd, filters)
+        log(full_cmd, filters, indent=indent)
         result = self.qmp(cmd, **kwargs)
-        log(result, filters)
+        log(result, filters, indent=indent)
         return result
 
     def run_job(self, job, auto_finalize=True, auto_dismiss=False):