Fix version detection for Postgres v10+

postgres/datadog_checks/postgres/postgres.py

@@ -6,11 +6,12 @@
 import re
 from contextlib import closing
 
+import pg8000
+from six.moves import zip_longest
 try:
     import psycopg2
 except ImportError:
     psycopg2 = None
-import pg8000
 
 from datadog_checks.checks import AgentCheck
 from datadog_checks.errors import CheckException
@@ -418,9 +419,15 @@ def _get_version(self, key, db):
     def _is_above(self, key, db, version_to_compare):
         version = self._get_version(key, db)
         if type(version) == list:
-            return version >= version_to_compare
+            # iterate from major down to bugfix
+            for v, vc in zip_longest(version, version_to_compare, fillvalue=0):
+                if v == vc:
+                    continue
 
-        return False
+                return v > vc
+
+        # return True if version is the same
+        return True
 
     def _is_8_3_or_above(self, key, db):
         return self._is_above(key, db, [8, 3, 0])
@@ -569,8 +576,9 @@ def _get_archiver_metrics(self, key, db):
         }
 
     def _get_replication_metrics(self, key, db):
-        """ Use either REPLICATION_METRICS_9_1 or REPLICATION_METRICS_9_1 + REPLICATION_METRICS_9_2
-        depending on the postgres version.
+        """ Use either REPLICATION_METRICS_10, REPLICATION_METRICS_9_1, or
+        REPLICATION_METRICS_9_1 + REPLICATION_METRICS_9_2, depending on the
+        postgres version.
         Uses a dictionnary to save the result for each instance
         """
         metrics = self.replication_metrics.get(key)

postgres/tests/test_unit.py

@@ -111,17 +111,20 @@ def test_is_above(check):
     """
     db = MagicMock()
 
-    # Test larger major versions
+    # Test major versions
     db.cursor().fetchone.return_value = ['10.5.4']
-    assert check._is_above('larger major', db, [9, 5, 4])
+    assert check._is_above('smaller major', db, [9, 5, 4])
+    assert check._is_above('larger major', db, [11, 0, 0]) is False
 
-    # Test minor version larger
+    # Test minor versions
     db.cursor().fetchone.return_value = ['10.5.4']
-    assert check._is_above('larger_minor', db, [9, 8, 4])
+    assert check._is_above('smaller minor', db, [10, 4, 4])
+    assert check._is_above('larger minor', db, [10, 6, 4]) is False
 
-    # Test patch version larger
+    # Test patch versions
     db.cursor().fetchone.return_value = ['10.5.4']
-    assert check._is_above('larger_patch', db, [9, 5, 8])
+    assert check._is_above('smaller patch', db, [10, 5, 3])
+    assert check._is_above('larger patch', db, [10, 5, 5]) is False
 
     # Test same version, _is_above() returns True for greater than or equal to
     db.cursor().fetchone.return_value = ['10.5.4']
@@ -135,6 +138,12 @@ def test_is_above(check):
     db.cursor().fetchone.return_value = ['11.0.0']
     assert check._is_above('official_release', db, [11, -1, 3])
 
+    # Test versions of unequal length
+    db.cursor().fetchone.return_value = ['10.0']
+    assert check._is_above('unequal_length', db, [10, 0])
+    assert check._is_above('unequal_length', db, [10, 0, 0])
+    assert check._is_above('unequal_length', db, [10, 0, 1]) is False
+
 
 def test_malformed_get_custom_queries(check):
     """