[PR #880/64aaa3dd backport][stable-3] postgresql_db: fix conn_limit 0 bug

changelogs/fragments/879-fix-conn-limit-zero.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - postgresql_db - Fix connection limit not being set when value is "0" (https://github.com/ansible-collections/community.postgresql/issues/879). 

plugins/modules/postgresql_db.py

@@ -479,7 +479,7 @@ def db_update(cursor, db, owner, encoding, lc_collate, lc_ctype, icu_locale, loc
     if owner and owner != db_info['owner']:
         changed = set_owner(cursor, db, owner)
 
-    if conn_limit and conn_limit != str(db_info['conn_limit']):
+    if conn_limit != '' and conn_limit != str(db_info['conn_limit']):
         changed = set_conn_limit(cursor, db, conn_limit)
 
     if tablespace and tablespace != db_info['tablespace']:
@@ -513,7 +513,7 @@ def db_matches(cursor, db, owner, template, encoding, lc_collate, lc_ctype, icu_
             return False
         elif owner and owner != db_info['owner']:
             return False
-        elif conn_limit and conn_limit != str(db_info['conn_limit']):
+        elif conn_limit != '' and conn_limit != str(db_info['conn_limit']):
             return False
         elif tablespace and tablespace != db_info['tablespace']:
             return False

tests/integration/targets/postgresql_db/tasks/main.yml

@@ -48,3 +48,6 @@
 
 # Test the comment feature
 - import_tasks: postgresql_db_comment.yml
+
+# Test connection limit zero fix (issue #879)
+- import_tasks: postgresql_db_conn_limit_zero.yml

tests/integration/targets/postgresql_db/tasks/postgresql_db_conn_limit_zero.yml

@@ -0,0 +1,104 @@
+---
+# Test for connection limit zero fix (issue #879)
+- name: Test connection limit zero - Create DB with conn_limit 0
+  become_user: "{{ pg_user }}"
+  become: true
+  postgresql_db:
+    name: test_conn_limit_zero
+    state: present
+    conn_limit: "0"
+    login_user: "{{ pg_user }}"
+  register: result
+
+- assert:
+    that:
+      - result is changed
+      - result.executed_commands == ['CREATE DATABASE "test_conn_limit_zero" CONNECTION LIMIT 0']
+
+- name: Test connection limit zero - Verify conn_limit is actually set to 0
+  become_user: "{{ pg_user }}"
+  become: true
+  postgresql_query:
+    query: "SELECT datconnlimit AS conn_limit FROM pg_database WHERE datname = 'test_conn_limit_zero'"
+  register: result
+
+- assert:
+    that:
+      - result.rowcount == 1
+      - result.query_result[0]['conn_limit'] == 0
+
+- name: Test connection limit zero - Run the same task again (should not change)
+  become_user: "{{ pg_user }}"
+  become: true
+  postgresql_db:
+    name: test_conn_limit_zero
+    state: present
+    conn_limit: "0"
+    login_user: "{{ pg_user }}"
+  register: result
+
+- assert:
+    that:
+      - result is not changed
+
+- name: Test connection limit zero - Change conn_limit to 100
+  become_user: "{{ pg_user }}"
+  become: true
+  postgresql_db:
+    name: test_conn_limit_zero
+    state: present
+    conn_limit: "100"
+    login_user: "{{ pg_user }}"
+  register: result
+
+- assert:
+    that:
+      - result is changed
+      - result.executed_commands == ['ALTER DATABASE "test_conn_limit_zero" CONNECTION LIMIT 100']
+
+- name: Test connection limit zero - Verify conn_limit is changed to 100
+  become_user: "{{ pg_user }}"
+  become: true
+  postgresql_query:
+    query: "SELECT datconnlimit AS conn_limit FROM pg_database WHERE datname = 'test_conn_limit_zero'"
+  register: result
+
+- assert:
+    that:
+      - result.rowcount == 1
+      - result.query_result[0]['conn_limit'] == 100
+
+- name: Test connection limit zero - Change conn_limit back to 0
+  become_user: "{{ pg_user }}"
+  become: true
+  postgresql_db:
+    name: test_conn_limit_zero
+    state: present
+    conn_limit: "0"
+    login_user: "{{ pg_user }}"
+  register: result
+
+- assert:
+    that:
+      - result is changed
+      - result.executed_commands == ['ALTER DATABASE "test_conn_limit_zero" CONNECTION LIMIT 0']
+
+- name: Test connection limit zero - Verify conn_limit is back to 0
+  become_user: "{{ pg_user }}"
+  become: true
+  postgresql_query:
+    query: "SELECT datconnlimit AS conn_limit FROM pg_database WHERE datname = 'test_conn_limit_zero'"
+  register: result
+
+- assert:
+    that:
+      - result.rowcount == 1
+      - result.query_result[0]['conn_limit'] == 0
+
+- name: Test connection limit zero - Cleanup test DB
+  become_user: "{{ pg_user }}"
+  become: true
+  postgresql_db:
+    name: test_conn_limit_zero
+    state: absent
+    login_user: "{{ pg_user }}"