Added search for PGPORT and PGUSER environment variables (#401)

* Added search for PGPORT and PGUSER environment variables

* Fix linter

* Added changelog fragment

* Added unit and integration tests

* Refactoring the script

* Fix linter

* Added a new test and code refactoring

---------

Co-authored-by: aleksvagachev <aleksvagachev@yandex.ru>

Author: aleksvagachev

changelogs/fragments/0-postgres.yml

@@ -0,0 +1,2 @@
+minor_changes:
+- postgresql - when receiving the connection parameters, the ``PGPORT`` and ``PGUSER`` environment variables are checked. The order of assigning values ``environment variables`` -> ``default values`` -> ``set values`` (https://github.com/ansible-collections/community.postgresql/issues/311).

plugins/module_utils/postgres.py

@@ -14,6 +14,7 @@
 
 from datetime import timedelta
 from decimal import Decimal
+from os import environ
 
 psycopg2 = None  # This line needs for unit tests
 try:
@@ -37,12 +38,22 @@ def postgres_common_argument_spec():
 
     The options are commonly used by most of PostgreSQL modules.
     """
+    # Getting a dictionary of environment variables
+    env_vars = environ
+
     return dict(
-        login_user=dict(default='postgres', aliases=['login']),
+        login_user=dict(
+            default='postgres' if not env_vars.get("PGUSER") else env_vars.get("PGUSER"),
+            aliases=['login']
+        ),
         login_password=dict(default='', no_log=True),
         login_host=dict(default='', aliases=['host']),
         login_unix_socket=dict(default='', aliases=['unix_socket']),
-        port=dict(type='int', default=5432, aliases=['login_port']),
+        port=dict(
+            type='int',
+            default=5432 if not env_vars.get("PGPORT") else int(env_vars.get("PGPORT")),
+            aliases=['login_port']
+        ),
         ssl_mode=dict(default='prefer', choices=['allow', 'disable', 'prefer', 'require', 'verify-ca', 'verify-full']),
         ca_cert=dict(aliases=['ssl_rootcert']),
         connect_params=dict(default={}, type='dict'),

tests/integration/targets/postgresql_ping/tasks/postgresql_ping_initial.yml

@@ -46,6 +46,63 @@
       - result.server_version == {}
       - result is not changed
 
+- name: postgresql_ping - check ping of the database on non-existent port does not return anything
+  become_user: "{{ pg_user }}"
+  become: true
+  environment:
+    PGPORT: 5435
+  ignore_errors: true
+  postgresql_ping:
+    db: "{{ db_default }}"
+    login_user: "{{ pg_user }}"
+  register: result
+
+- assert:
+    that:
+      - result.is_available == false
+      - result.server_version == {}
+      - result is not changed
+
+- name: postgresql_ping - check ping of the database by a non-existent user does not return anything
+  become_user: "{{ pg_user }}"
+  become: true
+  environment:
+    PGUSER: 'test_user'
+  ignore_errors: true
+  postgresql_ping:
+    db: "{{ db_default }}"
+  register: result
+
+- assert:
+    that:
+      - result.is_available == false
+      - result.server_version == {}
+      - result is not changed
+
+- name: Creating a "test_user" in postresql
+  shell:
+    cmd: psql -U "{{ pg_user }}" -c "CREATE ROLE test_user WITH LOGIN PASSWORD 'TEST_PASSWORD';"
+
+- name: postgresql_ping - check ping of the database by a existent user
+  become_user: "{{ pg_user }}"
+  become: true
+  environment:
+    PGUSER: 'test_user'
+  ignore_errors: true
+  postgresql_ping:
+    db: "{{ db_default }}"
+    login_password: "TEST_PASSWORD"
+  register: result
+
+- assert:
+    that:
+      - result.is_available == true
+      - result.server_version != {}
+      - result.server_version.raw is search('PostgreSQL')
+      - result.server_version.major != ''
+      - result.server_version.minor != ''
+      - result is not changed
+
 - name: postgresql_ping - ping DB with SSL
   become_user: "{{ pg_user }}"
   become: true

tests/unit/plugins/module_utils/test_postgres.py

@@ -3,6 +3,7 @@
 
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
+from os import environ
 
 import pytest
 
@@ -65,6 +66,15 @@ def test_postgres_common_argument_spec(self):
         )
         assert pg.postgres_common_argument_spec() == expected_dict
 
+        # Setting new values for checking environment variables
+        expected_dict['port']['default'] = 5435
+        expected_dict['login_user']['default'] = 'test_user'
+
+        # Setting environment variables
+        environ['PGUSER'] = 'test_user'
+        environ['PGPORT'] = '5435'
+        assert pg.postgres_common_argument_spec() == expected_dict
+
 
 @pytest.fixture
 def m_psycopg2():