New module postgresql_ping: Checks remote PostgreSQL server availability. (#51477)

* New module postgresql_ping: simple module to check remote PostgreSQL server availability.

* New module postgresql_ping: simple module to check remote PostgreSQL server availability, doc fixes

* postgresql_ping: added integration tests

* New module postgresql_ping: misc changes

* New module postgresql_ping: change return suit

* New module postgresql_ping: tests reformatting, return value

* Various cosmetic/documentation fixes

* A few more fixes

* And even more cleanups

* Fix PEP8 issue

test/integration/targets/postgresql/defaults/main.yml

@@ -4,7 +4,8 @@ db_name: 'ansible_db'
 db_user1: 'ansible_db_user1'
 db_user2: 'ansible_db_user2'
 db_user3: 'ansible_db_user3'
+db_default: 'postgres'
 
 tmp_dir: '/tmp'
 db_session_role1: 'session_role1'
-db_session_role2: 'session_role2'
+db_session_role2: 'session_role2'

test/integration/targets/postgresql/tasks/main.yml

@@ -771,6 +771,9 @@
 # Test postgresql_query module
 - include: postgresql_query.yml
 
+# Verify postgresql_ping module
+- include: postgresql_ping.yml db_name_nonexist=fake_db
+
 # dump/restore tests per format
 # ============================================================
 - include: state_dump_restore.yml test_fixture=user file=dbdata.sql

test/integration/targets/postgresql/tasks/postgresql_ping.yml

@@ -0,0 +1,35 @@
+# Test code for the postgresql_ping module
+# 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)
+
+- name: postgresql_ping - test return values
+  become_user: "{{ pg_user }}"
+  become: yes
+  postgresql_ping:
+    db: "{{ db_default }}"
+    login_user: "{{ pg_user }}"
+  register: result
+  ignore_errors: yes
+
+- assert:
+    that:
+      - result.is_available == true
+      - result.server_version != {}
+      - result.server_version.major != false
+      - result.server_version.minor != false
+      - result.changed == false
+
+- name: postgresql_ping - check ping of non-existing database doesn't return anything
+  become_user: "{{ pg_user }}"
+  become: yes
+  postgresql_ping:
+    db: "{{ db_name_nonexist }}"
+    login_user: "{{ pg_user }}"
+  register: result
+  ignore_errors: yes
+
+- assert:
+    that:
+      - result.is_available == false
+      - result.server_version == {}
+      - result.changed == false