#!/usr/bin/env python
# Jul 17 2005
#GenerateHostInfo - Joey Hagedorn - hagedorn@mcs.anl.gov

'''Generates hostinfo.xml at a regular interval'''
__revision__ = '$Revision$'

from ConfigParser import ConfigParser
from lxml.etree import parse, tostring
from os import fork, execl, dup2, wait, uname
import sys

if __name__ == '__main__':
    c = ConfigParser()
    c.read(['/etc/bcfg2.conf'])
    configpath = "%s/etc/report-configuration.xml" % c.get('server', 'repository')
    clientdatapath = "%s/Metadata/clients.xml" % c.get('server', 'repository')
    sendmailpath = c.get('statistics','sendmailpath')
    
    clientElement =  parse(clientdatapath)
    hostlist = [client.get('name') for client in clientElement.findall("Client")]

    pids = {}
    fullnames = {}
    null = open('/dev/null', 'w+')


    #use uname to detect OS and use -t for darwin and -w for linux
    #/bin/ping on linux /sbin/ping on os x
    osname = uname()[0]

    
    while hostlist or pids:
        if hostlist and len(pids.keys()) < 15:
            host = hostlist.pop()
            pid = fork()
            if pid == 0:
                # in child
                dup2(null.fileno(), sys.__stdin__.fileno())
                dup2(null.fileno(), sys.__stdout__.fileno())
                dup2(null.fileno(), sys.__stderr__.fileno())
                if osname == 'Linux':
                    execl('/bin/ping', 'ping', '-w', '5', '-c', '1', host)
                elif osname == 'Darwin':
                    execl('/sbin/ping', 'ping', '-t', '5', '-c', '1', host)
                elif osname == 'SunOS':
                    execl('/usr/sbin/ping', 'ping', host, '56', '1')
                else: #default
                    execl('/bin/ping', 'ping', '-w', '5', '-c', '1', host)
            else:
                pids[pid] = host
        else:
            try:
                (cpid, status) = wait()
            except OSError:
                continue
            chost = pids[cpid]
            del pids[cpid]
            if status == 0:
                try:
                    clientElement.xpath("//Client[@name='%s']"%chost)[0].set("pingable",'Y')
                except:#i think this is for a problem with aliases?
                    clientElement.xpath("//Client[@name='%s']"%fullnames[chost])[0].set("pingable",'Y')
                #also set pingtime, if you can get it

            else:
                if chost.count('.') > 0:
                    fullnames[chost.split('.')[0]] = chost
                    hostlist.append(chost.split('.')[0])
                else:
                    clientElement.xpath("//Client[@name='%s']"%(fullnames[chost]))[0].set("pingable",'N')
                    #also set pingtime if you can get it

    fout = open(clientdatapath, 'w')
    fout.write(tostring(clientElement.getroot()))
    fout.close()