module_utils.postgres: added unittests (#56381)

lib/ansible/module_utils/postgres.py

@@ -27,9 +27,9 @@
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 # USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+psycopg2 = None  # This line needs for unit tests
 try:
     import psycopg2
-    from psycopg2.extras import DictCursor
     HAS_PSYCOPG2 = True
 except ImportError:
     HAS_PSYCOPG2 = False
@@ -55,6 +55,11 @@ def ensure_libs(sslrootcert=None):
 
 
 def postgres_common_argument_spec():
+    """
+    Return a dictionary with connection options.
+
+    The options are commonly used by most of PostgreSQL modules.
+    """
     return dict(
         login_user=dict(default='postgres'),
         login_password=dict(default='', no_log=True),
@@ -67,6 +72,7 @@ def postgres_common_argument_spec():
 
 
 def ensure_required_libs(module):
+    """Check required libraries."""
     if not HAS_PSYCOPG2:
         module.fail_json(msg=missing_required_lib('psycopg2'))
 
@@ -75,7 +81,14 @@ def ensure_required_libs(module):
 
 
 def connect_to_db(module, autocommit=False, fail_on_conn=True, warn_db_default=True):
+    """Return psycopg2 connection object.
 
+    Keyword arguments:
+    module -- object of ansible.module_utils.basic.AnsibleModule class
+    autocommit -- commit automatically (default False)
+    fail_on_conn -- fail if connection failed or just warn and return None (default True)
+    warn_db_default -- warn that the default DB is used (default True)
+    """
     ensure_required_libs(module)
 
     # To use defaults values, keyword arguments must be absent, so
@@ -110,22 +123,24 @@ def connect_to_db(module, autocommit=False, fail_on_conn=True, warn_db_default=T
     if is_localhost and module.params["login_unix_socket"] != "":
         kw["host"] = module.params["login_unix_socket"]
 
+    db_connection = None
     try:
         db_connection = psycopg2.connect(**kw)
         if autocommit:
-            if psycopg2.__version__ >= '2.4.2':
+            if LooseVersion(psycopg2.__version__) >= LooseVersion('2.4.2'):
                 db_connection.set_session(autocommit=True)
             else:
                 db_connection.set_isolation_level(psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
 
         # Switch role, if specified:
-        cursor = db_connection.cursor(cursor_factory=DictCursor)
         if module.params.get('session_role'):
+            cursor = db_connection.cursor(cursor_factory=psycopg2.extras.DictCursor)
             try:
                 cursor.execute('SET ROLE %s' % module.params['session_role'])
             except Exception as e:
                 module.fail_json(msg="Could not switch role: %s" % to_native(e))
-        cursor.close()
+            finally:
+                cursor.close()
 
     except TypeError as e:
         if 'sslrootcert' in e.args[0]:

test/units/module_utils/postgresql/test_postgres.py

@@ -0,0 +1,292 @@
+# Copyright: (c) 2019, Andrew Klychkov (@Andersson007) <aaklychkov@mail.ru>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+import pytest
+
+import ansible.module_utils.postgres as pg
+
+
+class TestPostgresCommonArgSpec():
+
+    """
+    Namespace for testing postgresql_common_arg_spec() function.
+    """
+
+    def test_postgres_common_argument_spec(self):
+        """
+        Test for postgresql_common_arg_spec() function.
+
+        The tested function just returns a dictionary with the default
+        parameters and their values for PostgreSQL modules.
+        The return and expected dictionaries must be compared.
+        """
+        expected_dict = dict(
+            login_user=dict(default='postgres'),
+            login_password=dict(default='', no_log=True),
+            login_host=dict(default=''),
+            login_unix_socket=dict(default=''),
+            port=dict(type='int', default=5432, aliases=['login_port']),
+            ssl_mode=dict(
+                default='prefer',
+                choices=['allow', 'disable', 'prefer', 'require', 'verify-ca', 'verify-full']
+            ),
+            ca_cert=dict(aliases=['ssl_rootcert']),
+        )
+        assert pg.postgres_common_argument_spec() == expected_dict
+
+
+@pytest.fixture
+def m_psycopg2():
+    """Return mock object for psycopg2 emulation."""
+    global Cursor
+    Cursor = None
+
+    class Cursor():
+        def __init__(self):
+            self.passed_query = None
+
+        def execute(self, query):
+            self.passed_query = query
+
+        def close(self):
+            pass
+
+    global DbConnection
+    DbConnection = None
+
+    class DbConnection():
+        def __init__(self):
+            pass
+
+        def cursor(self, cursor_factory=None):
+            return Cursor()
+
+        def set_session(self, autocommit=None):
+            pass
+
+        def set_isolation_level(self, isolevel):
+            pass
+
+    class Extras():
+        def __init__(self):
+            self.DictCursor = True
+
+    class Extensions():
+        def __init__(self):
+            self.ISOLATION_LEVEL_AUTOCOMMIT = True
+
+    class DummyPsycopg2():
+        def __init__(self):
+            self.__version__ = '2.4.3'
+            self.extras = Extras()
+            self.extensions = Extensions()
+
+        def connect(self, host=None, port=None, user=None,
+                    password=None, sslmode=None, sslrootcert=None):
+            if user == 'Exception':
+                raise Exception()
+
+            return DbConnection()
+
+    return DummyPsycopg2()
+
+
+class TestEnsureReqLibs():
+
+    """
+    Namespace for testing ensure_required_libs() function.
+
+    If there is something wrong with libs, the function invokes fail_json()
+    method of AnsibleModule object passed as an argument called 'module'.
+    Therefore we must check:
+    1. value of err_msg attribute of m_ansible_module mock object.
+    """
+
+    @pytest.fixture
+    def m_ansible_module(self, scope='class'):
+        """Return an object of dummy AnsibleModule class."""
+        class Dummym_ansible_module():
+            def __init__(self):
+                self.params = {'ca_cert': False}
+                self.err_msg = ''
+
+            def fail_json(self, msg):
+                self.err_msg = msg
+
+        return Dummym_ansible_module()
+
+    def test_ensure_req_libs_has_not_psycopg2(self, m_ansible_module):
+        """Test ensure_required_libs() with psycopg2 is None."""
+        # HAS_PSYCOPG2 is False by default
+        pg.ensure_required_libs(m_ansible_module)
+        assert 'Failed to import the required Python library (psycopg2)' in m_ansible_module.err_msg
+
+    def test_ensure_req_libs_has_psycopg2(self, m_ansible_module, monkeypatch):
+        """Test ensure_required_libs() with psycopg2 is not None."""
+        monkeypatch.setattr(pg, 'HAS_PSYCOPG2', True)
+
+        pg.ensure_required_libs(m_ansible_module)
+        assert m_ansible_module.err_msg == ''
+
+    def test_ensure_req_libs_ca_cert(self, m_ansible_module, m_psycopg2, monkeypatch):
+        """
+        Test with module.params['ca_cert'], psycopg2 version is suitable.
+        """
+        m_ansible_module.params['ca_cert'] = True
+        monkeypatch.setattr(pg, 'HAS_PSYCOPG2', True)
+        monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
+
+        pg.ensure_required_libs(m_ansible_module)
+        assert m_ansible_module.err_msg == ''
+
+    def test_ensure_req_libs_ca_cert_low_psycopg2_ver(self, m_ansible_module, m_psycopg2, monkeypatch):
+        """
+        Test with module.params['ca_cert'], psycopg2 version is wrong.
+        """
+        m_ansible_module.params['ca_cert'] = True
+        monkeypatch.setattr(pg, 'HAS_PSYCOPG2', True)
+        # Set wrong psycopg2 version number:
+        psycopg2 = m_psycopg2
+        psycopg2.__version__ = '2.4.2'
+        monkeypatch.setattr(pg, 'psycopg2', psycopg2)
+
+        pg.ensure_required_libs(m_ansible_module)
+        assert 'psycopg2 must be at least 2.4.3' in m_ansible_module.err_msg
+
+
+class TestConnectToDb():
+
+    """
+    Namespace for testing connect_to_db() function.
+
+    When some connection errors occure connect_to_db() caught any of them
+    and invoke fail_json() or warn() methods of AnsibleModule object
+    depending on the passed parameters.
+    connect_to_db may return db_connection object or None if errors occured.
+    Therefore we must check:
+    1. Values of err_msg and warn_msg attributes of m_ansible_module mock object.
+    2. Types of return objects (db_connection and cursor).
+    """
+
+    @pytest.fixture
+    def m_ansible_module(self, scope='class'):
+        """Return an object of dummy AnsibleModule class."""
+        class DummyAnsibleModule():
+            def __init__(self):
+                self.params = pg.postgres_common_argument_spec()
+                self.err_msg = ''
+                self.warn_msg = ''
+
+            def fail_json(self, msg):
+                self.err_msg = msg
+
+            def warn(self, msg):
+                self.warn_msg = msg
+
+        return DummyAnsibleModule()
+
+    def test_connect_to_db(self, m_ansible_module, monkeypatch, m_psycopg2):
+        """Test connect_to_db(), common test."""
+        monkeypatch.setattr(pg, 'HAS_PSYCOPG2', True)
+        monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
+
+        db_connection = pg.connect_to_db(m_ansible_module)
+        cursor = db_connection.cursor()
+        # if errors, db_connection returned as None:
+        assert isinstance(db_connection, DbConnection)
+        assert isinstance(cursor, Cursor)
+        assert m_ansible_module.err_msg == ''
+        # The default behaviour, normal in this case:
+        assert 'Database name has not been passed' in m_ansible_module.warn_msg
+
+    def test_session_role(self, m_ansible_module, monkeypatch, m_psycopg2):
+        """Test connect_to_db(), switch on session_role."""
+        monkeypatch.setattr(pg, 'HAS_PSYCOPG2', True)
+        monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
+
+        m_ansible_module.params['session_role'] = 'test_role'
+        db_connection = pg.connect_to_db(m_ansible_module)
+        cursor = db_connection.cursor()
+        # if errors, db_connection returned as None:
+        assert isinstance(db_connection, DbConnection)
+        assert isinstance(cursor, Cursor)
+        assert m_ansible_module.err_msg == ''
+        # The default behaviour, normal in this case:
+        assert 'Database name has not been passed' in m_ansible_module.warn_msg
+
+    def test_warn_db_default_non_default(self, m_ansible_module, monkeypatch, m_psycopg2):
+        """
+        Test connect_to_db(), warn_db_default arg passed as False (by default is True).
+        """
+        monkeypatch.setattr(pg, 'HAS_PSYCOPG2', True)
+        monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
+
+        db_connection = pg.connect_to_db(m_ansible_module, warn_db_default=False)
+        cursor = db_connection.cursor()
+        # if errors, db_connection returned as None:
+        assert isinstance(db_connection, DbConnection)
+        assert isinstance(cursor, Cursor)
+        assert m_ansible_module.err_msg == ''
+        assert m_ansible_module.warn_msg == ''
+        # pay attention that warn_db_defaul=True has been checked
+        # in the previous tests by
+        # assert('Database name has not been passed' in m_ansible_module.warn_msg)
+        # because of this is the default behavior
+
+    def test_fail_on_conn_true(self, m_ansible_module, monkeypatch, m_psycopg2):
+        """
+        Test connect_to_db(), fail_on_conn arg passed as True (the default behavior).
+        """
+        monkeypatch.setattr(pg, 'HAS_PSYCOPG2', True)
+        monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
+
+        m_ansible_module.params['login_user'] = 'Exception'  # causes Exception
+
+        db_connection = pg.connect_to_db(m_ansible_module, fail_on_conn=True)
+
+        assert 'unable to connect to database' in m_ansible_module.err_msg
+        assert db_connection is None
+
+    def test_fail_on_conn_false(self, m_ansible_module, monkeypatch, m_psycopg2):
+        """
+        Test connect_to_db(), fail_on_conn arg passed as False.
+        """
+        monkeypatch.setattr(pg, 'HAS_PSYCOPG2', True)
+        monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
+
+        m_ansible_module.params['login_user'] = 'Exception'  # causes Exception
+
+        db_connection = pg.connect_to_db(m_ansible_module, fail_on_conn=False)
+
+        assert m_ansible_module.err_msg == ''
+        assert 'PostgreSQL server is unavailable' in m_ansible_module.warn_msg
+        assert db_connection is None
+
+    def test_autocommit_true(self, m_ansible_module, monkeypatch, m_psycopg2):
+        """
+        Test connect_to_db(), autocommit arg passed as True (the default is False).
+        """
+        monkeypatch.setattr(pg, 'HAS_PSYCOPG2', True)
+
+        # case 1: psycopg2.__version >= 2.4.2 (the default in m_psycopg2)
+        monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
+
+        db_connection = pg.connect_to_db(m_ansible_module, autocommit=True)
+        cursor = db_connection.cursor()
+
+        # if errors, db_connection returned as None:
+        assert isinstance(db_connection, DbConnection)
+        assert isinstance(cursor, Cursor)
+        assert m_ansible_module.err_msg == ''
+
+        # case 2: psycopg2.__version < 2.4.2
+        m_psycopg2.__version__ = '2.4.1'
+        monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
+
+        db_connection = pg.connect_to_db(m_ansible_module, autocommit=True)
+        cursor = db_connection.cursor()
+
+        # if errors, db_connection returned as None:
+        assert isinstance(db_connection, DbConnection)
+        assert isinstance(cursor, Cursor)
+        assert 'psycopg2 must be at least 2.4.3' in m_ansible_module.err_msg