Allow user to specify maintenance DB (#32510)

This fix allows user to specify alternative maintenance DB
required for initial connection in Postgresql_db module.
Also, adds pep8 related fixes.

Fixes: #30017

Signed-off-by: Abhijeet Kasurde <akasurde@redhat.com>

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

@@ -72,6 +72,11 @@ options:
     version_added: "2.4"
     description:
       - Further arguments for pg_dump or pg_restore. Used when state is "dump" or "restore"
+  maintenance_db:
+    version_added: "2.5"
+    description:
+      - The value specifies the initial database (which is also called as maintenance DB) that Ansible connects to.
+    default: postgres
 author: "Ansible Core Team"
 extends_documentation_fragment:
 - postgres
@@ -112,18 +117,16 @@ EXAMPLES = '''
     target_opts: "-n public"
 '''
 
+import os
+import pipes
+import subprocess
 import traceback
 
-HAS_PSYCOPG2 = False
 try:
     import psycopg2
     import psycopg2.extras
-    import pipes
-    import subprocess
-    import os
-
 except ImportError:
-    pass
+    HAS_PSYCOPG2 = False
 else:
     HAS_PSYCOPG2 = True
 
@@ -149,11 +152,13 @@ def set_owner(cursor, db, owner):
     cursor.execute(query)
     return True
 
+
 def get_encoding_id(cursor, encoding):
     query = "SELECT pg_char_to_encoding(%(encoding)s) AS encoding_id;"
     cursor.execute(query, {'encoding': encoding})
     return cursor.fetchone()['encoding_id']
 
+
 def get_db_info(cursor, db):
     query = """
     SELECT rolname AS owner,
@@ -165,11 +170,13 @@ def get_db_info(cursor, db):
     cursor.execute(query, {'db': db})
     return cursor.fetchone()
 
+
 def db_exists(cursor, db):
     query = "SELECT * FROM pg_database WHERE datname=%(db)s"
     cursor.execute(query, {'db': db})
     return cursor.rowcount == 1
 
+
 def db_delete(cursor, db):
     if db_exists(cursor, db):
         query = "DROP DATABASE %s" % pg_quote_identifier(db, 'database')
@@ -178,6 +185,7 @@ def db_delete(cursor, db):
     else:
         return False
 
+
 def db_create(cursor, db, owner, template, encoding, lc_collate, lc_ctype):
     params = dict(enc=encoding, collate=lc_collate, ctype=lc_ctype)
     if not db_exists(cursor, db):
@@ -218,6 +226,7 @@ def db_create(cursor, db, owner, template, encoding, lc_collate, lc_ctype):
         else:
             return False
 
+
 def db_matches(cursor, db, owner, template, encoding, lc_collate, lc_ctype):
     if not db_exists(cursor, db):
         return False
@@ -235,6 +244,7 @@ def db_matches(cursor, db, owner, template, encoding, lc_collate, lc_ctype):
         else:
             return True
 
+
 def db_dump(module, target, target_opts="",
             db=None,
             user=None,
@@ -270,6 +280,7 @@ def db_dump(module, target, target_opts="",
 
     return do_with_password(module, cmd, password)
 
+
 def db_restore(module, target, target_opts="",
                db=None,
                user=None,
@@ -321,6 +332,7 @@ def db_restore(module, target, target_opts="",
 
     return do_with_password(module, cmd, password)
 
+
 def login_flags(db, host, port, user, db_prefix=True):
     """
     returns a list of connection argument strings each prefixed
@@ -344,6 +356,7 @@ def login_flags(db, host, port, user, db_prefix=True):
         flags.append(' --username={0}'.format(user))
     return flags
 
+
 def do_with_password(module, cmd, password):
     env = {}
     if password:
@@ -355,6 +368,7 @@ def do_with_password(module, cmd, password):
 # Module execution.
 #
 
+
 def main():
     argument_spec = pgutils.postgres_common_argument_spec()
     argument_spec.update(dict(
@@ -367,6 +381,7 @@ def main():
         state=dict(default="present", choices=["absent", "present", "dump", "restore"]),
         target=dict(default="", type="path"),
         target_opts=dict(default=""),
+        maintenance_db=dict(default="postgres"),
     ))
 
     module = AnsibleModule(
@@ -387,6 +402,7 @@ def main():
     target_opts = module.params["target_opts"]
     state = module.params["state"]
     changed = False
+    maintenance_db = module.params['maintenance_db']
 
     # To use defaults values, keyword arguments must be absent, so
     # check which values are empty and don't include in the **kw
@@ -414,7 +430,7 @@ def main():
 
     try:
         pgutils.ensure_libs(sslrootcert=module.params.get('ssl_rootcert'))
-        db_connection = psycopg2.connect(database="postgres", **kw)
+        db_connection = psycopg2.connect(database=maintenance_db, **kw)
 
         # Enable autocommit so we can create databases
         if psycopg2.__version__ >= '2.4.2':

test/sanity/pep8/legacy-files.txt

@@ -128,7 +128,6 @@ lib/ansible/modules/database/misc/riak.py
 lib/ansible/modules/database/mongodb/mongodb_parameter.py
 lib/ansible/modules/database/mongodb/mongodb_user.py
 lib/ansible/modules/database/mssql/mssql_db.py
-lib/ansible/modules/database/postgresql/postgresql_db.py
 lib/ansible/modules/database/postgresql/postgresql_ext.py
 lib/ansible/modules/database/postgresql/postgresql_lang.py
 lib/ansible/modules/database/postgresql/postgresql_schema.py