#!/usr/bin/env python2.5

"""
Collates the results of listvms from multiple VM servers.  Part of the xvm
suite.
"""

from itertools import chain
from subprocess import CalledProcessError, PIPE, Popen
from sys import argv, stdout
from cPickle import dump, loads

###

#import compiler
#
#class Unsafe_Source_Error(Exception):
#    def __init__(self,error,descr = None,node = None):
#        self.error = error
#        self.descr = descr
#        self.node = node
#        self.lineno = getattr(node,"lineno",None)
#        
#    def __repr__(self):
#        return "Line %d.  %s: %s" % (self.lineno, self.error, self.descr)
#    __str__ = __repr__    
#           
#class SafeEval(object):
#    
#    def visit(self, node,**kw):
#        cls = node.__class__
#        meth = getattr(self,'visit'+cls.__name__,self.default)
#        return meth(node, **kw)
#            
#    def default(self, node, **kw):
#        for child in node.getChildNodes():
#            return self.visit(child, **kw)
#            
#    visitExpression = default
#    
#    def visitConst(self, node, **kw):
#        return node.value
#
#    def visitDict(self,node,**kw):
#        return dict([(self.visit(k),self.visit(v)) for k,v in node.items])
#        
#    def visitTuple(self,node, **kw):
#        return tuple(self.visit(i) for i in node.nodes)
#        
#    def visitList(self,node, **kw):
#        return [self.visit(i) for i in node.nodes]
#
#class SafeEvalWithErrors(SafeEval):
#
#    def default(self, node, **kw):
#        raise Unsafe_Source_Error("Unsupported source construct",
#                                node.__class__,node)
#            
#    def visitName(self,node, **kw):
#        if node.name == 'None': return None
#        raise Unsafe_Source_Error("Strings must be quoted", 
#                                 node.name, node)
#                                 
#    # Add more specific errors if desired
#            
#def safe_eval(source, fail_on_error = True):
#    if source.strip() == '': return None
#    walker = fail_on_error and SafeEvalWithErrors() or SafeEval()
#    try:
#        ast = compiler.parse(source,"eval")
#    except SyntaxError, err:
#        raise
#    try:
#        return walker.visit(ast)
#    except Unsafe_Source_Error, err:
#        raise

###

def run(cmd):
  """
  Run the given command (a list of program and argument strings) and return the
  stdout as a string, raising a CalledProcessError if the program exited with a
  non-zero status.
  """
  p = Popen(cmd, stdout=PIPE)
  stdout = p.communicate()[0]
  if p.returncode != 0: raise CalledProcessError(p.returncode, cmd)
  return stdout

def main(argv):
  # Query each of the server for their VMs.
  # run('kinit -k host/sipb-vm-58.mit.edu'.split())
  # TODO get `servers` from a real list of all the VM hosts (instead of
  # hardcoding the list here)
  servers = [ 'black-mesa.mit.edu', 'sx-blade-2.mit.edu' ]
  # XXX
  results = [ loads(run(['remctl', server, 'remote', 'web', 'listvms', '--pickle']))
              for server in servers ]
  results = filter( lambda x: x is not None, results )

  # Merge the results and print.
  merged = {}
  for result in results: merged.update(result)
  if argv[1:] == ['--pickle']:
    dump(merged, stdout)
  else:
    print merged
    print '.'

if __name__ == '__main__':
  main(argv)

# vim:et:sw=2:ts=2