Postgres module_utils: add get_connect_params + unit tests (#58067)

* add get_conn_params

* add get_conn_params: add to the modules

lib/ansible/module_utils/postgres.py

@@ -66,52 +66,24 @@ def ensure_required_libs(module):
         module.fail_json(msg='psycopg2 must be at least 2.4.3 in order to use the ca_cert parameter')
 
 
-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
-    # check which values are empty and don't include in the **kw
-    # dictionary
-    params_map = {
-        "login_host": "host",
-        "login_user": "user",
-        "login_password": "password",
-        "port": "port",
-        "ssl_mode": "sslmode",
-        "ca_cert": "sslrootcert"
-    }
+def connect_to_db(module, conn_params, autocommit=False, fail_on_conn=True):
+    """Connect to a PostgreSQL database.
 
-    # Might be different in the modules:
-    if module.params.get('db'):
-        params_map['db'] = 'database'
-    elif module.params.get('database'):
-        params_map['database'] = 'database'
-    elif module.params.get('login_db'):
-        params_map['login_db'] = 'database'
-    else:
-        if warn_db_default:
-            module.warn('Database name has not been passed, '
-                        'used default database to connect to.')
+    Return psycopg2 connection object.
 
-    kw = dict((params_map[k], v) for (k, v) in iteritems(module.params)
-              if k in params_map and v != '' and v is not None)
+    Args:
+        module (AnsibleModule) -- object of ansible.module_utils.basic.AnsibleModule class
+        conn_params (dict) -- dictionary with connection parameters
 
-    # If a login_unix_socket is specified, incorporate it here.
-    is_localhost = "host" not in kw or kw["host"] is None or kw["host"] == "localhost"
-    if is_localhost and module.params["login_unix_socket"] != "":
-        kw["host"] = module.params["login_unix_socket"]
+    Kwargs:
+        autocommit (bool) -- commit automatically (default False)
+        fail_on_conn (bool) -- fail if connection failed or just warn and return None (default True)
+    """
+    ensure_required_libs(module)
 
     db_connection = None
     try:
-        db_connection = psycopg2.connect(**kw)
+        db_connection = psycopg2.connect(**conn_params)
         if autocommit:
             if LooseVersion(psycopg2.__version__) >= LooseVersion('2.4.2'):
                 db_connection.set_session(autocommit=True)
@@ -179,3 +151,49 @@ def exec_sql(obj, query, ddl=False, add_to_executed=True):
     except Exception as e:
         obj.module.fail_json(msg="Cannot execute SQL '%s': %s" % (query, to_native(e)))
     return False
+
+
+def get_conn_params(module, params_dict, warn_db_default=True):
+    """Get connection parameters from the passed dictionary.
+
+    Return a dictionary with parameters to connect to PostgreSQL server.
+
+    Args:
+        module (AnsibleModule) -- object of ansible.module_utils.basic.AnsibleModule class
+        params_dict (dict) -- dictionary with variables
+
+    Kwargs:
+        warn_db_default (bool) -- warn that the default DB is used (default True)
+    """
+    # To use defaults values, keyword arguments must be absent, so
+    # check which values are empty and don't include in the return dictionary
+    params_map = {
+        "login_host": "host",
+        "login_user": "user",
+        "login_password": "password",
+        "port": "port",
+        "ssl_mode": "sslmode",
+        "ca_cert": "sslrootcert"
+    }
+
+    # Might be different in the modules:
+    if params_dict.get('db'):
+        params_map['db'] = 'database'
+    elif params_dict.get('database'):
+        params_map['database'] = 'database'
+    elif params_dict.get('login_db'):
+        params_map['login_db'] = 'database'
+    else:
+        if warn_db_default:
+            module.warn('Database name has not been passed, '
+                        'used default database to connect to.')
+
+    kw = dict((params_map[k], v) for (k, v) in iteritems(params_dict)
+              if k in params_map and v != '' and v is not None)
+
+    # If a login_unix_socket is specified, incorporate it here.
+    is_localhost = "host" not in kw or kw["host"] is None or kw["host"] == "localhost"
+    if is_localhost and params_dict["login_unix_socket"] != "":
+        kw["host"] = params_dict["login_unix_socket"]
+
+    return kw

lib/ansible/modules/database/postgresql/postgresql_copy.py

@@ -178,6 +178,7 @@ from ansible.module_utils.database import pg_quote_identifier
 from ansible.module_utils.postgres import (
     connect_to_db,
     exec_sql,
+    get_conn_params,
     postgres_common_argument_spec,
 )
 from ansible.module_utils.six import iteritems
@@ -351,7 +352,8 @@ def main():
         module.fail_json(msg='src param is necessary with copy_to')
 
     # Connect to DB and make cursor object:
-    db_connection = connect_to_db(module, autocommit=False)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=False)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     ##############

lib/ansible/modules/database/postgresql/postgresql_ext.py

@@ -143,7 +143,11 @@ except ImportError:
     pass
 
 from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils.postgres import connect_to_db, postgres_common_argument_spec
+from ansible.module_utils.postgres import (
+    connect_to_db,
+    get_conn_params,
+    postgres_common_argument_spec,
+)
 from ansible.module_utils._text import to_native
 from ansible.module_utils.database import pg_quote_identifier
 
@@ -216,7 +220,8 @@ def main():
     cascade = module.params["cascade"]
     changed = False
 
-    db_connection = connect_to_db(module, autocommit=True)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=True)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     try:

lib/ansible/modules/database/postgresql/postgresql_idx.py

@@ -230,6 +230,7 @@ from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.postgres import (
     connect_to_db,
     exec_sql,
+    get_conn_params,
     postgres_common_argument_spec,
 )
 
@@ -474,7 +475,8 @@ def main():
     if cascade and state != 'absent':
         module.fail_json(msg="cascade parameter used only with state=absent")
 
-    db_connection = connect_to_db(module, autocommit=True)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=True)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     # Set defaults:

lib/ansible/modules/database/postgresql/postgresql_info.py

@@ -475,7 +475,11 @@ except ImportError:
     pass
 
 from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils.postgres import connect_to_db, postgres_common_argument_spec
+from ansible.module_utils.postgres import (
+    connect_to_db,
+    get_conn_params,
+    postgres_common_argument_spec,
+)
 from ansible.module_utils._text import to_native
 
 
@@ -502,7 +506,8 @@ class PgDbConn(object):
 
         Note: connection parameters are passed by self.module object.
         """
-        self.db_conn = connect_to_db(self.module, warn_db_default=False)
+        conn_params = get_conn_params(self.module, self.module.params, warn_db_default=False)
+        self.db_conn = connect_to_db(self.module, conn_params)
         return self.db_conn.cursor(cursor_factory=DictCursor)
 
     def reconnect(self, dbname):

lib/ansible/modules/database/postgresql/postgresql_lang.py

@@ -170,7 +170,11 @@ queries:
 '''
 
 from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils.postgres import connect_to_db, postgres_common_argument_spec
+from ansible.module_utils.postgres import (
+    connect_to_db,
+    get_conn_params,
+    postgres_common_argument_spec,
+)
 from ansible.module_utils._text import to_native
 from ansible.module_utils.database import pg_quote_identifier
 
@@ -254,7 +258,8 @@ def main():
     cascade = module.params["cascade"]
     fail_on_drop = module.params["fail_on_drop"]
 
-    db_connection = connect_to_db(module, autocommit=False)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=False)
     cursor = db_connection.cursor()
 
     changed = False

lib/ansible/modules/database/postgresql/postgresql_membership.py

@@ -147,6 +147,7 @@ from ansible.module_utils.database import pg_quote_identifier
 from ansible.module_utils.postgres import (
     connect_to_db,
     exec_sql,
+    get_conn_params,
     postgres_common_argument_spec,
 )
 
@@ -284,7 +285,8 @@ def main():
     fail_on_role = module.params['fail_on_role']
     state = module.params['state']
 
-    db_connection = connect_to_db(module, autocommit=False)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=False)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     ##############

lib/ansible/modules/database/postgresql/postgresql_owner.py

@@ -161,6 +161,7 @@ from ansible.module_utils.database import pg_quote_identifier
 from ansible.module_utils.postgres import (
     connect_to_db,
     exec_sql,
+    get_conn_params,
     postgres_common_argument_spec,
 )
 
@@ -415,7 +416,8 @@ def main():
     reassign_owned_by = module.params['reassign_owned_by']
     fail_on_role = module.params['fail_on_role']
 
-    db_connection = connect_to_db(module, autocommit=False)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=False)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     ##############

lib/ansible/modules/database/postgresql/postgresql_ping.py

@@ -82,6 +82,7 @@ from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.postgres import (
     connect_to_db,
     exec_sql,
+    get_conn_params,
     postgres_common_argument_spec,
 )
 
@@ -138,7 +139,8 @@ def main():
         server_version=dict(),
     )
 
-    db_connection = connect_to_db(module, fail_on_conn=False)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, fail_on_conn=False)
 
     if db_connection is not None:
         cursor = db_connection.cursor(cursor_factory=DictCursor)

lib/ansible/modules/database/postgresql/postgresql_query.py

@@ -146,7 +146,11 @@ except ImportError:
     pass
 
 from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils.postgres import connect_to_db, postgres_common_argument_spec
+from ansible.module_utils.postgres import (
+    connect_to_db,
+    get_conn_params,
+    postgres_common_argument_spec,
+)
 from ansible.module_utils._text import to_native
 
 
@@ -189,7 +193,8 @@ def main():
         except Exception as e:
             module.fail_json(msg="Cannot read file '%s' : %s" % (path_to_script, to_native(e)))
 
-    db_connection = connect_to_db(module, autocommit=False)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=False)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     # Prepare args:

lib/ansible/modules/database/postgresql/postgresql_schema.py

@@ -129,7 +129,11 @@ except ImportError:
     pass
 
 from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils.postgres import connect_to_db, postgres_common_argument_spec
+from ansible.module_utils.postgres import (
+    connect_to_db,
+    get_conn_params,
+    postgres_common_argument_spec,
+)
 from ansible.module_utils.database import SQLParseError, pg_quote_identifier
 from ansible.module_utils._text import to_native
 
@@ -234,7 +238,8 @@ def main():
     cascade_drop = module.params["cascade_drop"]
     changed = False
 
-    db_connection = connect_to_db(module, autocommit=True)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=True)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     try:

lib/ansible/modules/database/postgresql/postgresql_sequence.py

@@ -287,6 +287,7 @@ from ansible.module_utils.database import pg_quote_identifier
 from ansible.module_utils.postgres import (
     connect_to_db,
     exec_sql,
+    get_conn_params,
     postgres_common_argument_spec,
 )
 
@@ -498,7 +499,8 @@ def main():
     # Change autocommit to False if check_mode:
     autocommit = not module.check_mode
     # Connect to DB and make cursor object:
-    db_connection = connect_to_db(module, autocommit=autocommit)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=autocommit)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     ##############

lib/ansible/modules/database/postgresql/postgresql_set.py

@@ -165,7 +165,11 @@ except Exception:
 from copy import deepcopy
 
 from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils.postgres import connect_to_db, postgres_common_argument_spec
+from ansible.module_utils.postgres import (
+    connect_to_db,
+    get_conn_params,
+    postgres_common_argument_spec,
+)
 from ansible.module_utils._text import to_native
 
 PG_REQ_VER = 90400
@@ -304,7 +308,8 @@ def main():
     if not value and not reset:
         module.fail_json(msg="%s: at least one of value or reset param must be specified" % name)
 
-    db_connection = connect_to_db(module, autocommit=True, warn_db_default=False)
+    conn_params = get_conn_params(module, module.params, warn_db_default=False)
+    db_connection = connect_to_db(module, conn_params, autocommit=True)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     kw = {}
@@ -397,7 +402,7 @@ def main():
 
     # Reconnect and recheck current value:
     if context in ('sighup', 'superuser-backend', 'backend', 'superuser', 'user'):
-        db_connection = connect_to_db(module, autocommit=True)
+        db_connection = connect_to_db(module, conn_params, autocommit=True)
         cursor = db_connection.cursor(cursor_factory=DictCursor)
 
         res = param_get(cursor, module, name)

lib/ansible/modules/database/postgresql/postgresql_slot.py

@@ -152,6 +152,7 @@ from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.postgres import (
     connect_to_db,
     exec_sql,
+    get_conn_params,
     postgres_common_argument_spec,
 )
 
@@ -242,7 +243,8 @@ def main():
     if immediately_reserve and slot_type == 'logical':
         module.fail_json(msg="Module parameters immediately_reserve and slot_type=logical are mutually exclusive")
 
-    db_connection = connect_to_db(module, autocommit=True)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=True)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     ##################################

lib/ansible/modules/database/postgresql/postgresql_table.py

@@ -240,6 +240,7 @@ from ansible.module_utils.database import pg_quote_identifier
 from ansible.module_utils.postgres import (
     connect_to_db,
     exec_sql,
+    get_conn_params,
     postgres_common_argument_spec,
 )
 
@@ -514,7 +515,8 @@ def main():
     if including and not like:
         module.fail_json(msg="%s: including param needs like param specified" % table)
 
-    db_connection = connect_to_db(module, autocommit=False)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=False)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     if storage_params:

lib/ansible/modules/database/postgresql/postgresql_tablespace.py

@@ -176,6 +176,7 @@ from ansible.module_utils.database import pg_quote_identifier
 from ansible.module_utils.postgres import (
     connect_to_db,
     exec_sql,
+    get_conn_params,
     postgres_common_argument_spec,
 )
 
@@ -394,7 +395,8 @@ def main():
         module.fail_json(msg="state=absent is mutually exclusive location, "
                              "owner, rename_to, and set")
 
-    db_connection = connect_to_db(module, autocommit=True)
+    conn_params = get_conn_params(module, module.params)
+    db_connection = connect_to_db(module, conn_params, autocommit=True)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     # Change autocommit to False if check_mode:

lib/ansible/modules/database/postgresql/postgresql_user.py

@@ -244,7 +244,11 @@ except ImportError:
 
 from ansible.module_utils.basic import AnsibleModule
 from ansible.module_utils.database import pg_quote_identifier, SQLParseError
-from ansible.module_utils.postgres import connect_to_db, postgres_common_argument_spec
+from ansible.module_utils.postgres import (
+    connect_to_db,
+    get_conn_params,
+    postgres_common_argument_spec,
+)
 from ansible.module_utils._text import to_bytes, to_native
 from ansible.module_utils.six import iteritems
 
@@ -801,7 +805,8 @@ def main():
     conn_limit = module.params["conn_limit"]
     role_attr_flags = module.params["role_attr_flags"]
 
-    db_connection = connect_to_db(module, warn_db_default=False)
+    conn_params = get_conn_params(module, module.params, warn_db_default=False)
+    db_connection = connect_to_db(module, conn_params)
     cursor = db_connection.cursor(cursor_factory=DictCursor)
 
     try:

test/units/module_utils/postgresql/test_postgres.py

@@ -6,6 +6,33 @@ import pytest
 import ansible.module_utils.postgres as pg
 
 
+INPUT_DICT = dict(
+    session_role=dict(default=''),
+    login_user=dict(default='postgres'),
+    login_password=dict(default='test', no_log=True),
+    login_host=dict(default='test'),
+    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']),
+)
+
+EXPECTED_DICT = dict(
+    user=dict(default='postgres'),
+    password=dict(default='test', no_log=True),
+    host=dict(default='test'),
+    port=dict(type='int', default=5432, aliases=['login_port']),
+    sslmode=dict(
+        default='prefer',
+        choices=['allow', 'disable', 'prefer', 'require', 'verify-ca', 'verify-full']
+    ),
+    sslrootcert=dict(aliases=['ssl_rootcert']),
+)
+
+
 class TestPostgresCommonArgSpec():
 
     """
@@ -154,6 +181,24 @@ class TestEnsureReqLibs():
         assert 'psycopg2 must be at least 2.4.3' in m_ansible_module.err_msg
 
 
+@pytest.fixture(scope='class')
+def m_ansible_module():
+    """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()
+
+
 class TestConnectToDb():
 
     """
@@ -168,29 +213,13 @@ class TestConnectToDb():
     2. Types of return objects (db_connection and cursor).
     """
 
-    @pytest.fixture(scope='class')
-    def m_ansible_module(self):
-        """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)
+        conn_params = pg.get_conn_params(m_ansible_module, m_ansible_module.params)
+        db_connection = pg.connect_to_db(m_ansible_module, conn_params)
         cursor = db_connection.cursor()
         # if errors, db_connection returned as None:
         assert isinstance(db_connection, DbConnection)
@@ -205,7 +234,8 @@ class TestConnectToDb():
         monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
 
         m_ansible_module.params['session_role'] = 'test_role'
-        db_connection = pg.connect_to_db(m_ansible_module)
+        conn_params = pg.get_conn_params(m_ansible_module, m_ansible_module.params)
+        db_connection = pg.connect_to_db(m_ansible_module, conn_params)
         cursor = db_connection.cursor()
         # if errors, db_connection returned as None:
         assert isinstance(db_connection, DbConnection)
@@ -214,25 +244,6 @@ class TestConnectToDb():
         # 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).
@@ -242,7 +253,8 @@ class TestConnectToDb():
 
         m_ansible_module.params['login_user'] = 'Exception'  # causes Exception
 
-        db_connection = pg.connect_to_db(m_ansible_module, fail_on_conn=True)
+        conn_params = pg.get_conn_params(m_ansible_module, m_ansible_module.params)
+        db_connection = pg.connect_to_db(m_ansible_module, conn_params, fail_on_conn=True)
 
         assert 'unable to connect to database' in m_ansible_module.err_msg
         assert db_connection is None
@@ -256,7 +268,8 @@ class TestConnectToDb():
 
         m_ansible_module.params['login_user'] = 'Exception'  # causes Exception
 
-        db_connection = pg.connect_to_db(m_ansible_module, fail_on_conn=False)
+        conn_params = pg.get_conn_params(m_ansible_module, m_ansible_module.params)
+        db_connection = pg.connect_to_db(m_ansible_module, conn_params, fail_on_conn=False)
 
         assert m_ansible_module.err_msg == ''
         assert 'PostgreSQL server is unavailable' in m_ansible_module.warn_msg
@@ -271,7 +284,8 @@ class TestConnectToDb():
         # 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)
+        conn_params = pg.get_conn_params(m_ansible_module, m_ansible_module.params)
+        db_connection = pg.connect_to_db(m_ansible_module, conn_params, autocommit=True)
         cursor = db_connection.cursor()
 
         # if errors, db_connection returned as None:
@@ -283,10 +297,26 @@ class TestConnectToDb():
         m_psycopg2.__version__ = '2.4.1'
         monkeypatch.setattr(pg, 'psycopg2', m_psycopg2)
 
-        db_connection = pg.connect_to_db(m_ansible_module, autocommit=True)
+        conn_params = pg.get_conn_params(m_ansible_module, m_ansible_module.params)
+        db_connection = pg.connect_to_db(m_ansible_module, conn_params, 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
+
+
+class TestGetConnParams():
+
+    """Namespace for testing get_conn_params() function."""
+
+    def test_get_conn_params_def(self, m_ansible_module):
+        """Test get_conn_params(), warn_db_default kwarg is default."""
+        assert pg.get_conn_params(m_ansible_module, INPUT_DICT) == EXPECTED_DICT
+        assert m_ansible_module.warn_msg == 'Database name has not been passed, used default database to connect to.'
+
+    def test_get_conn_params_warn_db_def_false(self, m_ansible_module):
+        """Test get_conn_params(), warn_db_default kwarg is False."""
+        assert pg.get_conn_params(m_ansible_module, INPUT_DICT, warn_db_default=False) == EXPECTED_DICT
+        assert m_ansible_module.warn_msg == ''