Add a new module to handle schema with postgres (#1883)

lib/ansible/modules/extras/database/postgresql/postgresql_schema.py

@@ -0,0 +1,266 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+DOCUMENTATION = '''
+---
+module: postgresql_schema
+short_description: Add or remove PostgreSQL schema from a remote host.
+description:
+   - Add or remove PostgreSQL schema from a remote host.
+version_added: "2.2"
+options:
+  name:
+    description:
+      - name of the schema to add or remove
+    required: true
+    default: null
+  database:
+    description:
+      - name of the database to connect to
+    required: false
+    default: postgres
+  login_user:
+    description:
+      - The username used to authenticate with
+    required: false
+    default: null
+  login_password:
+    description:
+      - The password used to authenticate with
+    required: false
+    default: null
+  login_host:
+    description:
+      - Host running the database
+    required: false
+    default: localhost
+  login_unix_socket:
+    description:
+      - Path to a Unix domain socket for local connections
+    required: false
+    default: null
+  owner:
+    description:
+      - Name of the role to set as owner of the schema
+    required: false
+    default: null
+  port:
+    description:
+      - Database port to connect to.
+    required: false
+    default: 5432
+  state:
+    description:
+      - The schema state
+    required: false
+    default: present
+    choices: [ "present", "absent" ]
+notes:
+   - This module uses I(psycopg2), a Python PostgreSQL database adapter. You must ensure that psycopg2 is installed on
+     the host before using this module. If the remote host is the PostgreSQL server (which is the default case), then PostgreSQL must also be installed on the remote host. For Ubuntu-based systems, install the C(postgresql), C(libpq-dev), and C(python-psycopg2) packages on the remote host before using this module.
+requirements: [ psycopg2 ]
+author: "Flavien Chantelot <contact@flavien.io>"
+'''
+
+EXAMPLES = '''
+# Create a new schema with name "acme"
+- postgresql_schema: name=acme
+# Create a new schema "acme" with a user "bob" who will own it
+- postgresql_schema: name=acme owner=bob
+
+'''
+
+RETURN = '''
+schema:
+    description: Name of the schema
+    returned: success, changed
+    type: string
+    sample: "acme"
+'''
+
+
+try:
+    import psycopg2
+    import psycopg2.extras
+except ImportError:
+    postgresqldb_found = False
+else:
+    postgresqldb_found = True
+
+class NotSupportedError(Exception):
+    pass
+
+
+# ===========================================
+# PostgreSQL module specific support methods.
+#
+
+def set_owner(cursor, schema, owner):
+    query = "ALTER SCHEMA %s OWNER TO %s" % (
+            pg_quote_identifier(schema, 'schema'),
+            pg_quote_identifier(owner, 'role'))
+    cursor.execute(query)
+    return True
+
+def get_schema_info(cursor, schema):
+    query = """
+    SELECT schema_owner AS owner
+    FROM information_schema.schemata
+    WHERE schema_name = %(schema)s
+    """
+    cursor.execute(query, {'schema': schema})
+    return cursor.fetchone()
+
+def schema_exists(cursor, schema):
+    query = "SELECT schema_name FROM information_schema.schemata WHERE schema_name = %(schema)s"
+    cursor.execute(query, {'schema': schema})
+    return cursor.rowcount == 1
+
+def schema_delete(cursor, schema):
+    if schema_exists(cursor, schema):
+        query = "DROP SCHEMA %s" % pg_quote_identifier(schema, 'schema')
+        cursor.execute(query)
+        return True
+    else:
+        return False
+
+def schema_create(cursor, schema, owner):
+    if not schema_exists(cursor, schema):
+        query_fragments = ['CREATE SCHEMA %s' % pg_quote_identifier(schema, 'schema')]
+        if owner:
+            query_fragments.append('AUTHORIZATION %s' % pg_quote_identifier(owner, 'role'))
+        query = ' '.join(query_fragments)
+        cursor.execute(query)
+        return True
+    else:
+        schema_info = get_schema_info(cursor, schema)
+        if owner and owner != schema_info['owner']:
+            return set_owner(cursor, schema, owner)
+        else:
+            return False
+
+def schema_matches(cursor, schema, owner):
+    if not schema_exists(cursor, schema):
+        return False
+    else:
+        schema_info = get_schema_info(cursor, schema)
+        if owner and owner != schema_info['owner']:
+            return False
+        else:
+            return True
+
+# ===========================================
+# Module execution.
+#
+
+def main():
+    module = AnsibleModule(
+        argument_spec=dict(
+            login_user=dict(default="postgres"),
+            login_password=dict(default=""),
+            login_host=dict(default=""),
+            login_unix_socket=dict(default=""),
+            port=dict(default="5432"),
+            schema=dict(required=True, aliases=['name']),
+            owner=dict(default=""),
+            database=dict(default="postgres"),
+            state=dict(default="present", choices=["absent", "present"]),
+        ),
+        supports_check_mode = True
+    )
+
+    if not postgresqldb_found:
+        module.fail_json(msg="the python psycopg2 module is required")
+
+    schema = module.params["schema"]
+    owner = module.params["owner"]
+    state = module.params["state"]
+    database = module.params["database"]
+    changed = False
+
+    # To use defaults values, keyword arguments must be absent, so
+    # check which values are empty and don't include in the **kw
+    # dictionary
+    params_map = {
+        "login_host":"host",
+        "login_user":"user",
+        "login_password":"password",
+        "port":"port"
+    }
+    kw = dict( (params_map[k], v) for (k, v) in module.params.iteritems()
+              if k in params_map and v != '' )
+
+    # If a login_unix_socket is specified, incorporate it here.
+    is_localhost = "host" not in kw or kw["host"] == "" or kw["host"] == "localhost"
+    if is_localhost and module.params["login_unix_socket"] != "":
+        kw["host"] = module.params["login_unix_socket"]
+
+    try:
+        db_connection = psycopg2.connect(database=database, **kw)
+        # Enable autocommit so we can create databases
+        if psycopg2.__version__ >= '2.4.2':
+            db_connection.autocommit = True
+        else:
+            db_connection.set_isolation_level(psycopg2
+                                              .extensions
+                                              .ISOLATION_LEVEL_AUTOCOMMIT)
+        cursor = db_connection.cursor(
+                cursor_factory=psycopg2.extras.DictCursor)
+    except Exception:
+        e = get_exception()
+        module.fail_json(msg="unable to connect to database: %s" %(text, str(e)))
+
+    try:
+        if module.check_mode:
+            if state == "absent":
+                changed = not schema_exists(cursor, schema)
+            elif state == "present":
+                changed = not schema_matches(cursor, schema, owner)
+            module.exit_json(changed=changed, schema=schema)
+
+        if state == "absent":
+            try:
+                changed = schema_delete(cursor, schema)
+            except SQLParseError:
+                e = get_exception()
+                module.fail_json(msg=str(e))
+
+        elif state == "present":
+            try:
+                changed = schema_create(cursor, schema, owner)
+            except SQLParseError:
+                e = get_exception()
+                module.fail_json(msg=str(e))
+    except NotSupportedError:
+        e = get_exception()
+        module.fail_json(msg=str(e))
+    except SystemExit:
+        # Avoid catching this on Python 2.4
+        raise
+    except Exception:
+        e = get_exception()
+        module.fail_json(msg="Database query failed: %s" %(text, str(e)))
+
+    module.exit_json(changed=changed, schema=schema)
+
+# import module snippets
+from ansible.module_utils.basic import *
+from ansible.module_utils.database import *
+if __name__ == '__main__':
+    main()
+