qemu-iotests: 041: More robust assertion on quorum node

Block nodes are now assigned names automatically, therefore the test
case is fragile in using fixed indices in result. Introduce a method in
iotests.py and do the matching more sensibly.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 1460518995-1338-1-git-send-email-famz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

tests/qemu-iotests/041

@@ -810,8 +810,7 @@ class TestRepairQuorum(iotests.QMPTestCase):
         self.assert_qmp(result, 'return', {})
 
         self.complete_and_wait(drive="quorum0")
-        result = self.vm.qmp('query-named-block-nodes')
+        self.assert_has_block_node("repair0", quorum_repair_img)
-        self.assert_qmp(result, 'return[0]/file', quorum_repair_img)
         # TODO: a better test requiring some QEMU infrastructure will be added
         #       to check that this file is really driven by quorum
         self.vm.shutdown()
@@ -833,8 +832,7 @@ class TestRepairQuorum(iotests.QMPTestCase):
         self.cancel_and_wait(drive="quorum0", force=True)
         # here we check that the last registered quorum file has not been
         # swapped out and unref
-        result = self.vm.qmp('query-named-block-nodes')
+        self.assert_has_block_node(None, quorum_img3)
-        self.assert_qmp(result, 'return[1]/file', quorum_img3)
         self.vm.shutdown()
 
     def test_cancel_after_ready(self):
@@ -850,10 +848,9 @@ class TestRepairQuorum(iotests.QMPTestCase):
         self.assert_qmp(result, 'return', {})
 
         self.wait_ready_and_cancel(drive="quorum0")
-        result = self.vm.qmp('query-named-block-nodes')
         # here we check that the last registered quorum file has not been
         # swapped out and unref
-        self.assert_qmp(result, 'return[1]/file', quorum_img3)
+        self.assert_has_block_node(None, quorum_img3)
         self.vm.shutdown()
         self.assertTrue(iotests.compare_images(quorum_img2, quorum_repair_img),
                         'target image does not match source after mirroring')
@@ -974,8 +971,7 @@ class TestRepairQuorum(iotests.QMPTestCase):
         self.assert_qmp(result, 'return', {})
 
         self.complete_and_wait(drive="quorum0")
-        result = self.vm.qmp('query-named-block-nodes')
+        self.assert_has_block_node("repair0", quorum_repair_img)
-        self.assert_qmp(result, 'return[0]/file', quorum_repair_img)
         # TODO: a better test requiring some QEMU infrastructure will be added
         #       to check that this file is really driven by quorum
         self.vm.shutdown()

tests/qemu-iotests/iotests.py

@@ -348,6 +348,20 @@ class QMPTestCase(unittest.TestCase):
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return', [])
 
+    def assert_has_block_node(self, node_name=None, file_name=None):
+        """Issue a query-named-block-nodes and assert node_name and/or
+        file_name is present in the result"""
+        def check_equal_or_none(a, b):
+            return a == None or b == None or a == b
+        assert node_name or file_name
+        result = self.vm.qmp('query-named-block-nodes')
+        for x in result["return"]:
+            if check_equal_or_none(x.get("node-name"), node_name) and \
+                    check_equal_or_none(x.get("file"), file_name):
+                return
+        self.assertTrue(False, "Cannot find %s %s in result:\n%s" % \
+                (node_name, file_name, result))
+
     def cancel_and_wait(self, drive='drive0', force=False, resume=False):
         '''Cancel a block job and wait for it to finish, returning the event'''
         result = self.vm.qmp('block-job-cancel', device=drive, force=force)