Using argparse to call method in various Classes?

Sun Jul 17 21:39:30 EDT 2011

Hi,
I'm attempting to use argparse to write a simple script to perform operations on various types of servers:
manage_servers.py <operation> <type_of_server> 
Operations are things like check, build, deploy, configure, verify etc.
Types of server are just different types of inhouse servers we use.
We have a generic server class, and specific types that inherit from that:
class Server
 def configure_logging(self, loggin_file):
 ...
 def check(self):
 ...
 def deploy(self):
 ...
 def configure(self):
 ...
 def __init__(self, hostname):
 self.hostname = hostname
 logging = self.configure_logging(LOG_FILENAME)
class SpamServer(Server):
 def check(self):
 ...
class HamServer(Server):
 def deploy(self):
 ...
My question is how to link that all up to argparse?
Originally, I was using argparse subparses for the operations (check, build, deploy) and another argument for the type.
subparsers = parser.add_subparsers(help='The operation that you want to run on the server.')
parser_check = subparsers.add_parser('check', help='Check that the server has been setup correctly.')
parser_build = subparsers.add_parser('build', help='Download and build a copy of the execution stack.')
parser_build.add_argument('-r', '--revision', help='SVN revision to build from.')
...
parser.add_argument('type_of_server', action='store', choices=types_of_servers,
 help='The type of server you wish to create.')
Normally, you'd link each subparse to a method - and then pass in the type_of_server as an argument. However, that's slightly backwards due to the classes- I need to create an instance of the appropriate Server class, then call the operation method inside of that - not a generic check/build/configure module
Any ideas of how I could achieve the above? Perhaps a different design pattern for Servers? Or any way to mould argparse to work with this?
Thanks,
Victor