Climate client now shows the list of commands

HelpAction was removed from the parser to delay its
execution, otherwise the available commands were not
printed. I have also added a description for each
command to be displayed when running the 'help' command
in climate client.

Change-Id: Ic030a184f066e78daf556af8b26a02e79ef9c39a
Closes-Bug: #1311264

climateclient/shell.py

@@ -93,7 +93,7 @@ class HelpAction(argparse.Action):
         max_len = 0
         app = self.default
         parser.print_help(app.stdout)
-        app.stdout.write('\nCommands for API v%s:\n' % app.api_version)
+        app.stdout.write('\nCommands for API %s:\n' % app.api_version)
         command_manager = app.command_manager
         for name, ep in sorted(command_manager):
             factory = ep.load()
@@ -144,7 +144,7 @@ class ClimateShell(app.App):
             dest='verbose_level',
             const=0,
             help='suppress output except warnings and errors')
-        parser.add_argument(
+        help_action = parser.add_argument(
             '-h', '--help',
             action=HelpAction,
             nargs=0,
@@ -156,6 +156,19 @@ class ClimateShell(app.App):
             action='store_true',
             help='show tracebacks on errors')
 
+        # Removes help action to defer its execution
+        self.deferred_help_action = help_action
+        parser._actions.remove(help_action)
+        del parser._option_string_actions['-h']
+        del parser._option_string_actions['--help']
+        parser.add_argument(
+            '-h', '--help',
+            action='store_true',
+            dest='deferred_help',
+            default=False,
+            help="Show this help message and exit",
+        )
+
         # Global arguments
         parser.add_argument(
             '--os-reservation-api-version',
@@ -299,6 +312,9 @@ class ClimateShell(app.App):
             if help_command_pos > -1 and command_pos == -1:
                 argv[help_command_pos] = '--help'
 
+            if self.options.deferred_help:
+                self.deferred_help_action(self.parser, self.parser, None, None)
+
             self.configure_logging()
             self.interactive_mode = not remainder
             self.initialize_app(remainder)

climateclient/v1/shell_commands/hosts.py

@@ -19,6 +19,7 @@ from climateclient import command
 
 
 class ListHosts(command.ListCommand):
+    """Print a list of host reservations."""
     resource = 'host'
     log = logging.getLogger(__name__ + '.ListHosts')
     list_columns = ['id', 'hypervisor_hostname', 'vcpus', 'memory_mb',
@@ -35,6 +36,7 @@ class ListHosts(command.ListCommand):
 
 
 class ShowHost(command.ShowCommand):
+    """Show host reservation details."""
     resource = 'host'
     json_indent = 4
     # NOTE(sbauza): We can't find by name as there is currently no column
@@ -44,6 +46,7 @@ class ShowHost(command.ShowCommand):
 
 
 class CreateHost(command.CreateCommand):
+    """Create a host reservation."""
     resource = 'host'
     json_indent = 4
     log = logging.getLogger(__name__ + '.CreateHost')
@@ -79,6 +82,7 @@ class CreateHost(command.CreateCommand):
 
 
 class UpdateHost(command.UpdateCommand):
+    """Update a host reservation."""
     resource = 'host'
     allow_names = False
     log = logging.getLogger(__name__ + '.UpdateHost')
@@ -108,6 +112,7 @@ class UpdateHost(command.UpdateCommand):
 
 
 class DeleteHost(command.DeleteCommand):
+    """Delete a host reservation."""
     resource = 'host'
     # NOTE(sbauza): We can't find by name as there is currently no column
     #  called 'name' but rather 'hypervisor_hostname'

climateclient/v1/shell_commands/leases.py

@@ -23,6 +23,7 @@ from climateclient import exception
 
 
 class ListLeases(command.ListCommand):
+    """Print a list of leases."""
     resource = 'lease'
     log = logging.getLogger(__name__ + '.ListLeases')
     list_columns = ['id', 'name', 'start_date', 'end_date']
@@ -38,12 +39,14 @@ class ListLeases(command.ListCommand):
 
 
 class ShowLease(command.ShowCommand):
+    """Show details about the given lease."""
     resource = 'lease'
     json_indent = 4
     log = logging.getLogger(__name__ + '.ShowLease')
 
 
 class CreateLease(command.CreateCommand):
+    """Create a lease."""
     resource = 'lease'
     log = logging.getLogger(__name__ + '.CreateLease')
     default_start = datetime.datetime.utcnow()
@@ -219,6 +222,7 @@ class CreateLease(command.CreateCommand):
 
 
 class UpdateLease(command.UpdateCommand):
+    """Update a lease."""
     resource = 'lease'
     log = logging.getLogger(__name__ + '.UpdateLease')
 
@@ -260,5 +264,6 @@ class UpdateLease(command.UpdateCommand):
 
 
 class DeleteLease(command.DeleteCommand):
+    """Delete a lease."""
     resource = 'lease'
     log = logging.getLogger(__name__ + '.DeleteLease')