glance-manage should work like nova-manage

nova-manage supports subcommands of db, for nova-manage,
eg) 'nova-manage db sync',
glance manage however has individual commands like db_sync, db_version
etc. This patch aims at adding the db operations as subcommands to db in
glance-manage similar to nova and refactoring this bit of code in
cmd/manage.py

Fixes: bug 1213197
Change-Id: I6fad31766bc1cec2a666a7ebc8df5c732007c5f1

doc/source/configuring.rst

@@ -173,7 +173,7 @@ Optional. Default: ``1``
 * ``db_auto_create=False``
 
 Whether to automatically create the database tables.  Otherwise you can
-manually run `glance-manage db_sync`.
+manually run `glance-manage db sync`.
 
 Optional. Default: ``False``
 

doc/source/db.rst

@@ -21,27 +21,31 @@ The default metadata driver for glance uses sqlalchemy, which implies there
 exists a backend database which must be managed. The ``glance-manage`` binary
 provides a set of commands for making this easier.
 
+The commands should be executed as a subcommand of 'db':
 
-Initializing an Empty Database
-------------------------------
+    glance-manage db <cmd> <args>
 
-    glance-manage db_sync
 
-This will take an empty database and create the necessary tables.
+Sync the Database
+-----------------
+
+    glance-manage db sync <version> <current_version>
+
+Place a database under migration control and upgrade, creating it first if necessary.
 
 
 Determining the Database Version
 --------------------------------
 
-    glance-manage db_version
+    glance-manage db version
 
-This will print the version of a glance database.
+This will print the current migration level of a glance database.
 
 
 Upgrading an Existing Database
 ------------------------------
 
-    glance-manage db_sync <VERSION>
+    glance-manage db upgrade <VERSION>
 
 This will take an existing database and upgrade it to the specified VERSION.
 
@@ -49,7 +53,7 @@ This will take an existing database and upgrade it to the specified VERSION.
 Downgrading an Existing Database
 --------------------------------
 
-    glance-manage downgrade <VERSION>
+    glance-manage db downgrade <VERSION>
 
 This will downgrade an existing database from the current version to the
 specified VERSION.

doc/source/man/glancemanage.rst

@@ -24,7 +24,7 @@ DESCRIPTION
 glance-manage is a utility for managing and configuring a Glance installation.
 One important use of glance-manage is to setup the database. To do this run::
 
-    glance-manage db_sync
+    glance-manage db sync
 
 OPTIONS
 =======

glance/cmd/manage.py

@@ -44,69 +44,130 @@ from oslo.config import cfg
 from glance.common import config
 from glance.common import exception
 import glance.db.sqlalchemy.api
-import glance.db.sqlalchemy.migration
+from glance.db.sqlalchemy import migration
 from glance.openstack.common import log
 
 CONF = cfg.CONF
 
 
-def do_db_version():
-    """Print database's current migration level"""
-    print(glance.db.sqlalchemy.migration.db_version())
+# Decorators for actions
+def args(*args, **kwargs):
+    def _decorator(func):
+        func.__dict__.setdefault('args', []).insert(0, (args, kwargs))
+        return func
+    return _decorator
 
 
-def do_upgrade():
-    """Upgrade the database's migration level"""
-    glance.db.sqlalchemy.migration.upgrade(CONF.command.version)
+class DbCommands(object):
+    """Class for managing the db"""
+
+    def __init__(self):
+        pass
+
+    def version(self):
+        """Print database's current migration level"""
+        print(migration.db_version())
+
+    @args('--version', metavar='<version>', help='Database version')
+    def upgrade(self, version=None):
+        """Upgrade the database's migration level"""
+        migration.upgrade(version)
+
+    @args('--version', metavar='<version>', help='Database version')
+    def downgrade(self, version=None):
+        """Downgrade the database's migration level"""
+        migration.downgrade(version)
+
+    @args('--version', metavar='<version>', help='Database version')
+    def version_control(self, version=None):
+        """Place a database under migration control"""
+        migration.version_control(version)
+
+    @args('--version', metavar='<version>', help='Database version')
+    @args('--current_version', metavar='<version>',
+          help='Current Database version')
+    def sync(self, version=None, current_version=None):
+        """
+        Place a database under migration control and upgrade,
+        creating first if necessary.
+        """
+        migration.db_sync(version, current_version)
 
 
-def do_downgrade():
-    """Downgrade the database's migration level"""
-    glance.db.sqlalchemy.migration.downgrade(CONF.command.version)
+def add_legacy_command_parsers(command_object, subparsers):
 
-
-def do_version_control():
-    """Place a database under migration control"""
-    glance.db.sqlalchemy.migration.version_control(CONF.command.version)
-
-
-def do_db_sync():
-    """
-    Place a database under migration control and upgrade,
-    creating first if necessary.
-    """
-    glance.db.sqlalchemy.migration.db_sync(CONF.command.version,
-                                           CONF.command.current_version)
-
-
-def add_command_parsers(subparsers):
     parser = subparsers.add_parser('db_version')
-    parser.set_defaults(func=do_db_version)
+    parser.set_defaults(action_fn=command_object.version)
 
-    parser = subparsers.add_parser('upgrade')
-    parser.set_defaults(func=do_upgrade)
+    parser = subparsers.add_parser('db_upgrade')
+    parser.set_defaults(action_fn=command_object.upgrade)
     parser.add_argument('version', nargs='?')
 
-    parser = subparsers.add_parser('downgrade')
-    parser.set_defaults(func=do_downgrade)
+    parser = subparsers.add_parser('db_downgrade')
+    parser.set_defaults(action_fn=command_object.downgrade)
     parser.add_argument('version')
 
-    parser = subparsers.add_parser('version_control')
-    parser.set_defaults(func=do_version_control)
+    parser = subparsers.add_parser('db_version_control')
+    parser.set_defaults(action_fn=command_object.version_control)
     parser.add_argument('version', nargs='?')
 
     parser = subparsers.add_parser('db_sync')
-    parser.set_defaults(func=do_db_sync)
+    parser.set_defaults(action_fn=command_object.sync)
     parser.add_argument('version', nargs='?')
     parser.add_argument('current_version', nargs='?')
 
 
+def add_command_parsers(subparsers):
+    command_object = DbCommands()
+
+    parser = subparsers.add_parser('db')
+    parser.set_defaults(command_object=command_object)
+
+    category_subparsers = parser.add_subparsers(dest='action')
+
+    for (action, action_fn) in methods_of(command_object):
+        parser = category_subparsers.add_parser(action)
+
+        action_kwargs = []
+        for args, kwargs in getattr(action_fn, 'args', []):
+            # FIXME(basha): hack to assume dest is the arg name without
+            # the leading hyphens if no dest is supplied
+            kwargs.setdefault('dest', args[0][2:])
+            if kwargs['dest'].startswith('action_kwarg_'):
+                action_kwargs.append(
+                    kwargs['dest'][len('action_kwarg_'):])
+            else:
+                action_kwargs.append(kwargs['dest'])
+                kwargs['dest'] = 'action_kwarg_' + kwargs['dest']
+
+            parser.add_argument(*args, **kwargs)
+
+        parser.set_defaults(action_fn=action_fn)
+        parser.set_defaults(action_kwargs=action_kwargs)
+
+        parser.add_argument('action_args', nargs='*')
+
+        add_legacy_command_parsers(command_object, subparsers)
+
+
 command_opt = cfg.SubCommandOpt('command',
                                 title='Commands',
                                 help='Available commands',
                                 handler=add_command_parsers)
 
 
+def methods_of(obj):
+    """Get all callable methods of an object that don't start with underscore
+
+    returns a list of tuples of the form (method_name, method)
+    """
+    result = []
+    for i in dir(obj):
+        if callable(getattr(obj, i)) and not i.startswith('_'):
+            result.append((i, getattr(obj, i)))
+    return result
+
+
 def main():
     CONF.register_cli_opt(command_opt)
     try:
@@ -125,7 +186,8 @@ def main():
         sys.exit("ERROR: %s" % e)
 
     try:
-        CONF.command.func()
+
+        CONF.command.action_fn()
     except exception.GlanceException as e:
         sys.exit("ERROR: %s" % e)
 

glance/tests/functional/__init__.py

@@ -215,7 +215,7 @@ class Server(object):
                 os.system('cp %s %s/tests.sqlite'
                           % (db_location, self.test_dir))
             else:
-                cmd = ('%s -m glance.cmd.manage --config-file %s db_sync' %
+                cmd = ('%s -m glance.cmd.manage --config-file %s db sync' %
                        (sys.executable, conf_filepath))
                 execute(cmd, no_venv=self.no_venv, exec_env=self.exec_env,
                         expect_exit=True)

glance/tests/functional/test_glance_manage.py

@@ -44,7 +44,7 @@ class TestGlanceManage(functional.FunctionalTest):
             conf_file.write(self.connection)
             conf_file.flush()
 
-        cmd = ('%s -m glance.cmd.manage --config-file %s db_sync' %
+        cmd = ('%s -m glance.cmd.manage --config-file %s db sync' %
                (sys.executable, self.conf_filepath))
         execute(cmd, raise_error=True)