Issue 2200 - PART I/II - Migrate to argparse

run.py

 #!/usr/bin/env python
 # coding: utf-8
 
 import argparse
 import sys
 import os
 import re
 import subprocess
-import getopt
 import yaml
 
 def createArgumentParser(**kwargs):
   parser = argparse.ArgumentParser(**kwargs)
   parser.add_argument(
-    '-u', metavar='<user>', dest='user', type=str, default='vagrant',
+    '-u', '--user', metavar='user', dest='user', type=str, default='vagrant',
     help='user name for use with SSH, must exist on all hosts'
-  )
-
-  parser.add_argument(
-    '-?', action='help',
-    help='print this message and exit'
   )
 

[Wladimir Palant, 2015/04/07 14:58:04]

This is just wrong...

1) This assumes add_help=False parameter, yet you require the caller to pass it
in explicitly.

2) Why even do this? Just let argparse take care of it. This will be more
consistent anyway - -? is usually used on Windows, Unix tools should support
--help.

[mathias, 2015/04/07 15:36:51]

I just tried to stay consistent with the existing arguments for now. But yes
this makes things more complicated. Thus I've now removed these kludges, so the
default handling can apply again. Though that required re-naming '-h' into '-t'
and '--target' (in run.py).

   return parser
 
 def parseOptions(args):
-  description = "Run a command on the given hosts or groups of hosts"

[Wladimir Palant, 2015/04/07 14:58:04]

Nit: single quotes, for consistency.

[mathias, 2015/04/07 15:36:51]

Done.

-  parser = createArgumentParser(description=description, add_help=False)
+  description = 'Run a command on the given hosts or groups of hosts'
+  parser = createArgumentParser(description=description)
   parser.add_argument(
-    '-i', action='store_true', dest='ignore_errors',
+    '-i', '--ignore-errors', action='store_true', dest='ignore_errors',
     help='continue execution on next host in case of an error'
   )
 
   hosts = set()
   parser.add_argument(
-    '-h', metavar='<host|group>',
+    '-t', '--target', metavar='host|group',
     help='target host or group, can be specified multiple times',
-    type=lambda value: hosts.update((value,)) 

[Wladimir Palant, 2015/04/07 14:58:04]

Nit: I think this should be a list semantically - hosts.update([value])

[mathias, 2015/04/07 15:36:51]

Done.

+    type=lambda value: hosts.update([value])
   )
 
   parser.add_argument(
     'args', metavar='command', type=str, nargs='+',
-    help='The command to run on the specified hosts'
+    help='the command to run on the specified hosts'
   )
 
   options = parser.parse_args(args)
   options.hosts = hosts
   return options
 
 def getValidHosts():
   dirname = os.path.dirname(sys.argv[0])
-  path_name = os.path.join(dirname, "modules", "private", "hiera", "hosts.yaml")
+  path_name = os.path.join(dirname, 'modules', 'private', 'hiera', 'hosts.yaml')
   with open(path_name, 'rb') as handle:
     config = yaml.load(handle)
   servers = config.get('servers', {})
   return servers  
 
 def resolveHostList(hosts):
 
   result = set()
 
   try:
@@ skipping 15 matching lines @@
       if len(chunk) == 0:
         print >>sys.stderr, 'Warning: failed to recognize host or group', name
       else:
         result.update(chunk)
 
   return result
 
 def runCommand(user, host, command, ignore_errors=False):
   if not isinstance(command, list):
     command = [command]
-  command = ["ssh"] + (["-l", user] if user else []) + [host] + command
+  command = ['ssh'] + (['-l', user] if user else []) + [host] + command
   if ignore_errors:
     subprocess.call(command)
   else:
     subprocess.check_call(command)
 
-if __name__ == "__main__":
+if __name__ == '__main__':
   options = parseOptions(sys.argv[1:])
   selectedHosts = resolveHostList(options.hosts)
   if len(selectedHosts) == 0:
     print >>sys.stderr, 'No valid hosts or groups specified, nothing to do'
     sys.exit(0)
   for host in selectedHosts:
     print >>sys.stderr, 'Running on %s...' % host
     runCommand(options.user, host, options.args, options.ignore_errors)