#!/usr/bin/env python
#  -*- mode: python; -*-
#============================================================================
# Copyright (C) 2004 Mike Wray <mike.wray@hp.com>
# Copyright (C) 2005 XenSource Ltd
#============================================================================

"""Xen management daemon.
   Provides console server and HTTP management api.

   Run:
   xend start

   Restart:
   xend restart

   The daemon is stopped with:
   xend stop

   The daemon should reconnect to device control interfaces
   and recover its state when restarted.
"""
import os
import sys
import socket
import signal
import time
import commands

# add fallback path for non-native python path installs if needed
sys.path.append('/usr/lib/python')
sys.path.append('/usr/lib64/python')
from xen.xend.server import SrvDaemon

class CheckError(ValueError):
    pass

def hline():
    print >>sys.stderr, "*" * 70

def msg(message):
    print >>sys.stderr, "*" * 3, message

def check_logging():
    """Check python logging is installed and raise an error if not.
    Logging is standard from Python 2.3 on.
    """
    try:
        import logging
    except ImportError:
        hline()
        msg("Python logging is not installed.")
        msg("Use 'make install-logging' at the xen root to install.")
        msg("")
        msg("Alternatively download and install from")
        msg("http://www.red-dove.com/python_logging.html")
        hline()
        raise CheckError("logging is not installed")

def check_user():
    """Check that the effective user id is 0 (root).
    """
    if os.geteuid() != 0:
        hline()
        msg("Xend must be run as root.")
        hline()
        raise CheckError("invalid user")

def start_xenstored():
    XENSTORED_TRACE = os.getenv("XENSTORED_TRACE")
    cmd = "xenstored --pid-file=/var/run/xenstore.pid"
    if XENSTORED_TRACE:
        cmd += " -T /var/log/xenstored-trace.log"
    s,o = commands.getstatusoutput(cmd)

def start_consoled():
    if os.fork() == 0:
        os.execvp('xenconsoled', ['xenconsoled'])
            
def main():
    try:
        check_logging()
        check_user()
    except CheckError:
        sys.exit(1)
    
    daemon = SrvDaemon.instance()
    if not sys.argv[1:]:
        print 'usage: %s {start|stop|restart}' % sys.argv[0]
    elif sys.argv[1] == 'start':
        start_xenstored()
        start_consoled()
        return daemon.start()
    elif sys.argv[1] == 'trace_start':
        start_xenstored()
        start_consoled()
        return daemon.start(trace=1)
    elif sys.argv[1] == 'stop':
        return daemon.stop()
    elif sys.argv[1] == 'restart':
        start_xenstored()
        start_consoled()
        return daemon.stop() or daemon.start()
    elif sys.argv[1] == 'status':
        return daemon.status()
    else:
        print 'not an option:', sys.argv[1]
    return 1

if __name__ == '__main__':
    sys.exit(main())