mysql_db: add config_overrides_defaults parameter (#513)

* mysql_db: add config_overrides_defaults parameter

* Add CI tests

* Add changelog fragment

* add more tests

* improve tests

* fix CI

* fix feature

changelogs/fragments/513-mysql_db_config_overrides_defaults.yml

@@ -0,0 +1,2 @@
+minor_changes:
+- mysql_db - add the ``config_overrides_defaults`` parameter (https://github.com/ansible/ansible/issues/26919).

plugins/module_utils/mysql.py

@@ -29,6 +29,8 @@
 
 import os
 
+from ansible.module_utils.six.moves import configparser
+
 try:
     import pymysql as mysql_driver
     _mysql_cursor_param = 'cursor'
@@ -43,10 +45,30 @@ except ImportError:
 mysql_driver_fail_msg = 'The PyMySQL (Python 2.7 and Python 3.X) or MySQL-python (Python 2.X) module is required.'
 
 
-def mysql_connect(module, login_user=None, login_password=None, config_file='', ssl_cert=None, ssl_key=None, ssl_ca=None, db=None, cursor_class=None,
-                  connect_timeout=30, autocommit=False):
+def parse_from_mysql_config_file(cnf):
+    cp = configparser.ConfigParser()
+    cp.read(cnf)
+    return cp
+
+
+def mysql_connect(module, login_user=None, login_password=None, config_file='', ssl_cert=None,
+                  ssl_key=None, ssl_ca=None, db=None, cursor_class=None,
+                  connect_timeout=30, autocommit=False, config_overrides_defaults=False):
     config = {}
 
+    if config_file and os.path.exists(config_file):
+        config['read_default_file'] = config_file
+        cp = parse_from_mysql_config_file(config_file)
+        # Override some commond defaults with values from config file if needed
+        if cp and cp.has_section('client') and config_overrides_defaults:
+            try:
+                module.params['login_host'] = cp.get('client', 'host', fallback=module.params['login_host'])
+                module.params['login_port'] = cp.getint('client', 'port', fallback=module.params['login_port'])
+            except Exception as e:
+                if "got an unexpected keyword argument 'fallback'" in e.message:
+                    module.fail_json('To use config_overrides_defaults, '
+                                     'it needs Python 3.5+ as the default interpreter on a target host')
+
     if ssl_ca is not None or ssl_key is not None or ssl_cert is not None:
         config['ssl'] = {}
 
@@ -56,9 +78,6 @@ def mysql_connect(module, login_user=None, login_password=None, config_file='',
         config['host'] = module.params['login_host']
         config['port'] = module.params['login_port']
 
-    if os.path.exists(config_file):
-        config['read_default_file'] = config_file
-
     # If login_user or login_password are given, they should override the
     # config file
     if login_user is not None:

plugins/modules/database/mysql/mysql_db.py

@@ -144,6 +144,15 @@ options:
     type: bool
     default: no
     version_added: '0.2.0'
+  config_overrides_defaults:
+    description:
+      - If C(yes), connection parameters from I(config_file) will override the default
+        values of I(login_host) and I(login_port) parameters.
+      - Used when I(stat) is C(present) or C(absent), ignored otherwise.
+      - It needs Python 3.5+ as the default interpreter on a target host.
+    type: bool
+    default: no
+    version_added: '0.2.0'
 
 seealso:
 - module: mysql_info
@@ -563,6 +572,7 @@ def main():
             unsafe_login_password=dict(type='bool', default=False),
             restrict_config_file=dict(type='bool', default=False),
             check_implicit_admin=dict(type='bool', default=False),
+            config_overrides_defaults=dict(type='bool', default=False),
         ),
         supports_check_mode=True,
     )
@@ -606,6 +616,7 @@ def main():
     use_shell = module.params["use_shell"]
     restrict_config_file = module.params["restrict_config_file"]
     check_implicit_admin = module.params['check_implicit_admin']
+    config_overrides_defaults = module.params['config_overrides_defaults']
 
     if len(db) > 1 and state == 'import':
         module.fail_json(msg="Multiple databases are not supported with state=import")
@@ -625,14 +636,15 @@ def main():
         if check_implicit_admin:
             try:
                 cursor, db_conn = mysql_connect(module, 'root', '', config_file, ssl_cert, ssl_key, ssl_ca,
-                                                connect_timeout=connect_timeout)
+                                                connect_timeout=connect_timeout,
+                                                config_overrides_defaults=config_overrides_defaults)
             except Exception as e:
                 check_implicit_admin = False
                 pass
 
         if not cursor:
             cursor, db_conn = mysql_connect(module, login_user, login_password, config_file, ssl_cert, ssl_key, ssl_ca,
-                                            connect_timeout=connect_timeout)
+                                            connect_timeout=connect_timeout, config_overrides_defaults=config_overrides_defaults)
     except Exception as e:
         if os.path.exists(config_file):
             module.fail_json(msg="unable to connect to database, check login_user and login_password are correct or %s has the credentials. "

tests/integration/targets/mysql_db/tasks/config_overrides_defaults.yml

@@ -0,0 +1,71 @@
+- set_fact:
+    db_to_create=testdb1
+    config_file="/root/.my1.cnf"
+    fake_port=9999
+    fake_host="blahblah.local"
+
+- name: Create custom config file
+  shell: 'echo "[client]" > {{ config_file }}'
+
+- name: Add fake port to config file
+  shell: 'echo "port = {{ fake_port }}" >> {{ config_file }}'
+
+- name: Create database using fake port to connect to, must fail
+  mysql_db:
+    name: '{{ db_to_create }}'
+    state: present
+    check_implicit_admin: yes
+    config_file: '{{ config_file }}'
+    config_overrides_defaults: yes
+  ignore_errors: yes
+  register: result
+
+- name: Must fail because login_port default has beed overriden by wrong value from config file
+  assert:
+    that:
+    - result is failed
+    - result.msg is search("unable to connect to database")
+
+- name: Create database using default port
+  mysql_db:
+    name: '{{ db_to_create }}'
+    state: present
+    check_implicit_admin: yes
+    config_file: '{{ config_file }}'
+    config_overrides_defaults: no
+    login_unix_socket: '{{ mysql_socket }}'
+  register: result
+
+- name: Must not fail because of the default of login_port is correct
+  assert:
+    that:
+    - result is changed
+
+- name: Reinit custom config file
+  shell: 'echo "[client]" > {{ config_file }}'
+
+- name: Add fake host to config file
+  shell: 'echo "host = {{ fake_host }}" >> {{ config_file }}'
+
+- name: Remove database using fake login_host
+  mysql_db:
+    name: '{{ db_to_create }}'
+    state: absent
+    config_file: '{{ config_file }}'
+    config_overrides_defaults: yes
+  register: result
+  ignore_errors: yes
+
+- name: Must fail because login_host default has beed overriden by wrong value from config file
+  assert:
+    that:
+    - result is failed
+    - result.msg is search("Can't connect to MySQL server on '{{ fake_host }}'")
+
+# Clean up
+- name: Remove test db
+  mysql_db:
+    name: '{{ db_to_create }}'
+    state: absent
+    check_implicit_admin: yes
+    login_unix_socket: '{{ mysql_socket }}'

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

@@ -258,3 +258,6 @@
 - include: multi_db_create_delete.yml 
 
 - include: encoding_dump_import.yml file=latin1.sql format_msg_type=ASCII
+
+- include: config_overrides_defaults.yml
+  when: ansible_python.version_info[0] >= 3