virt-subproc/VirtSubproc.py

   1 # VirtSubproc is part of autopkgtest
   2 # autopkgtest is a tool for testing Debian binary packages
   3 #
   4 # autopkgtest is Copyright (C) 2006 Canonical Ltd.
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 2 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 #
  20 # See the file CREDITS for a full list of credits information (often
  21 # installed as /usr/share/doc/autopkgtest/CREDITS).
  22
  23 import __main__
  24
  25 import sys
  26 import os
  27 import string
  28 import urllib
  29 import signal
  30 import subprocess
  31 import traceback
  32
  33 debuglevel = None
  34 progname = "<VirtSubproc>"
  35 devnull_read = file('/dev/null','r')
  36 caller = __main__
  37
  38 class Quit:
  39         def __init__(q,ec,m): q.ec = ec; q.m = m
  40
  41 def debug(m):
  42         if not debuglevel: return
  43         print >> sys.stderr, progname+": debug:", m
  44
  45 def bomb(m):
  46         raise Quit(12, progname+": failure: %s" % m)
  47
  48 def ok(): print 'ok'
  49
  50 def cmdnumargs(c, ce, nargs=0):
  51         if len(c) == nargs + 1: return
  52         bomb("wrong number of arguments to command `%s'" % ce[0])
  53
  54 def cmd_capabilities(c, ce):
  55         cmdnumargs(c, ce)
  56         return caller.hook_capabilities()
  57
  58 def cmd_quit(c, ce):
  59         cmdnumargs(c, ce)
  60         raise Quit(0, '')
  61
  62 def execute_raw(what, instr, *popenargs, **popenargsk):
  63         debug(" ++ %s" % string.join(popenargs[0]))
  64         sp = subprocess.Popen(*popenargs, **popenargsk)
  65         if instr is None: popenargsk['stdin'] = devnull_read
  66         (out, err) = sp.communicate(instr)
  67         if err: bomb("%s unexpectedly produced stderr output `%s'" %
  68                         (what, err))
  69         status = sp.wait()
  70         return (status, out)
  71
  72 def execute(cmd_string, cmd_list=[], downp=False, outp=False):
  73         cmdl = cmd_string.split()
  74
  75         if downp: perhaps_down = down
  76         else: downp = []
  77
  78         if outp: stdout = subprocess.PIPE
  79         else: stdout = None
  80
  81         cmd = cmdl + cmd_list
  82         if len(perhaps_down): cmd = perhaps_down + [' '.join(cmd)]
  83
  84         (status, out) = execute_raw(cmdl[0], None, cmd, stdout=stdout)
  85
  86         if status: bomb("%s%s failed (exit status %d)" %
  87                         ((downp and "(down) " or ""), cmdl[0], status))
  88
  89         if outp and out and out[-1]=='\n': out = out[:-1]
  90         return out
  91
  92 def cmd_open(c, ce):
  93         global downtmp
  94         cmdnumargs(c, ce)
  95         if downtmp: bomb("`open' when already open")
  96         downtmp = caller.hook_open()
  97         return [downtmp]
  98
  99 def cmd_close(c, ce):
 100         global downtmp
 101         cmdnumargs(c, ce)
 102         if not downtmp: bomb("`close' when not open")
 103         cleanup()
 104
 105 def cmd_stop(c, ce):
 106         global downtmp
 107         cmdnumargs(c, ce, 1)
 108         if not downtmp: bomb("`stop' when not open")
 109         caller.hook_stop()
 110         cleanup()
 111
 112 def down_python_script(gobody, functions=''):
 113         # Many things are made much harder by the inability of
 114         # dchroot, ssh, et al, to cope without mangling the arguments.
 115         # So we run a sub-python on the testbed and feed it a script
 116         # on stdin.  The sub-python decodes the arguments.
 117
 118         script = (      "import urllib\n"
 119                         "import os\n"
 120                         "def setfd(fd,fnamee,write,mode=0666):\n"
 121                         "       fname = urllib.unquote(fnamee)\n"
 122                         "       if write: rw = os.O_WRONLY|os.O_CREAT\n"
 123                         "       else: rw = os.O_RDONLY\n"
 124                         "       nfd = os.open(fname, rw, mode)\n"
 125                         "       os.dup2(nfd,fd)\n"
 126                         + functions +
 127                         "def go():\n" )
 128         script += (     "       os.environ['TMPDIR']= urllib.unquote('%s')\n" %
 129                                 urllib.quote(downtmp)   )
 130         script += (     "       os.chdir(os.environ['TMPDIR'])\n" )
 131         script += (     gobody +
 132                         "go()\n" )
 133
 134         debug("+P ...\n"+script)
 135
 136         scripte = urllib.quote(script)
 137         cmdl = down + ['python','-c',
 138                 "'import urllib; s = urllib.unquote(%s); exec s'" %
 139                         ('"%s"' % scripte)]
 140         return cmdl
 141
 142 def cmd_execute(c, ce):
 143         cmdnumargs(c, ce, 5)
 144         gobody = "      import sys\n"
 145         for ioe in range(3):
 146                 gobody += "     setfd(%d,'%s',%d)\n" % (
 147                         ioe, ce[ioe+2], ioe>0 )
 148         gobody += "     os.chdir(urllib.unquote('" + ce[5] +"'))\n"
 149         gobody += "     cmd = '%s'\n" % ce[1]
 150         gobody += ("    cmd = cmd.split(',')\n"
 151                 "       cmd = map(urllib.unquote, cmd)\n"
 152                 "       c0 = cmd[0]\n"
 153                 "       if '/' in c0:\n"
 154                 "               if not os.access(c0, os.X_OK):\n"
 155                 "                       status = os.stat(c0)\n"
 156                 "                       mode = status.st_mode | 0111\n"
 157                 "                       os.chmod(c0, mode)\n"
 158                 "       try: os.execvp(c0, cmd)\n"
 159                 "       except OSError, e:\n"
 160                 "               print >>sys.stderr, \"%s: %s\" % (\n"
 161                 "                       (c0, os.strerror(e.errno)))\n"
 162                 "               os._exit(127)\n")
 163         cmdl = down_python_script(gobody)
 164
 165         (status, out) = execute_raw('sub-python', None, cmdl,
 166                                 stdin=devnull_read, stderr=subprocess.PIPE)
 167         if out: bomb("sub-python unexpected produced stdout"
 168                         " visible to us `%s'" % out)
 169         return [`status`]
 170
 171 def copyupdown(c, ce, upp):
 172         cmdnumargs(c, ce, 2)
 173         isrc = 0
 174         idst = 1
 175         ilocal = 0 + upp
 176         iremote = 1 - upp
 177         wh = ce[0]
 178         sd = c[1:]
 179         sde = ce[1:]
 180         if not sd[0] or not sd[1]:
 181                 bomb("%s paths must be nonempty" % wh)
 182         dirsp = sd[0][-1]=='/'
 183         functions = "import errno\n"
 184         if dirsp != (sd[1][-1]=='/'):
 185                 bomb("% paths must agree about directoryness"
 186                         " (presence or absence of trailing /)" % wh)
 187         localfd = None
 188         deststdout = devnull_read
 189         srcstdin = devnull_read
 190         preexecfns = [None, None]
 191         if not dirsp:
 192                 modestr = ''
 193                 if upp:
 194                         deststdout = file(sd[idst], 'w')
 195                 else:
 196                         srcstdin = file(sd[isrc], 'r')
 197                         status = os.fstat(srcstdin.fileno())
 198                         if status.st_mode & 0111: modestr = ',0777'
 199                 gobody = "      setfd(%s,'%s',%s%s)\n" % (
 200                                         1-upp, sde[iremote], not upp, modestr)
 201                 gobody += "     os.execvp('cat', ['cat'])\n"
 202                 localcmdl = ['cat']
 203         else:
 204                 gobody = "      dir = urllib.unquote('%s')\n" % sde[iremote]
 205                 if upp:
 206                         try: os.mkdir(sd[ilocal])
 207                         except OSError, oe:
 208                                 if oe.errno != errno.EEXIST: raise
 209                 else:
 210                         gobody += ("    try: os.mkdir(dir)\n"
 211                                 "       except OSError, oe:\n"
 212                                 "               if oe.errno != errno.EEXIST: raise\n")
 213                 gobody +=( "    os.chdir(dir)\n"
 214                         "       tarcmd = 'tar -f -'.split()\n")
 215                 localcmdl = 'tar -f -'.split()
 216                 taropts = [None, None]
 217                 taropts[isrc] = '-c .'
 218                 taropts[idst] = '-p -x --no-same-owner'
 219                 gobody += "     tarcmd += '%s'.split()\n" % taropts[iremote]
 220                 localcmdl += ['-C',sd[ilocal]]
 221                 localcmdl += taropts[ilocal].split()
 222                 gobody += "     os.execvp('tar', tarcmd)\n";
 223
 224         downcmdl = down_python_script(gobody, functions)
 225
 226         if upp: cmdls = (downcmdl, localcmdl)
 227         else: cmdls = (localcmdl, downcmdl)
 228
 229         debug(`["cmdls", `cmdls`]`)
 230         debug(`["srcstdin", `srcstdin`, "deststdout", `deststdout`, "devnull_read", devnull_read]`)
 231
 232         subprocs = [None,None]
 233         debug(" +< %s" % string.join(cmdls[0]))
 234         subprocs[0] = subprocess.Popen(cmdls[0], stdin=srcstdin,
 235                         stdout=subprocess.PIPE, preexec_fn=preexecfns[0])
 236         debug(" +> %s" % string.join(cmdls[1]))
 237         subprocs[1] = subprocess.Popen(cmdls[1], stdin=subprocs[0].stdout,
 238                         stdout=deststdout, preexec_fn=preexecfns[1])
 239         for sdn in [1,0]:
 240                 status = subprocs[sdn].wait()
 241                 if status: bomb("%s %s failed, status %d" %
 242                         (wh, ['source','destination'][sdn], status))
 243
 244 def cmd_copydown(c, ce): copyupdown(c, ce, False)
 245 def cmd_copyup(c, ce): copyupdown(c, ce, True)
 246
 247 def command():
 248         sys.stdout.flush()
 249         ce = sys.stdin.readline()
 250         if not ce: bomb('end of file - caller quit?')
 251         ce = ce.rstrip().split()
 252         c = map(urllib.unquote, ce)
 253         if not c: bomb('empty commands are not permitted')
 254         debug('executing '+string.join(ce))
 255         try: f = globals()['cmd_'+c[0]]
 256         except KeyError: bomb("unknown command `%s'" % ce[0])
 257         r = f(c, ce)
 258         if not r: r = []
 259         r.insert(0, 'ok')
 260         ru = map(urllib.quote, r)
 261         print string.join(ru)
 262
 263 def cleanup():
 264         global downtmp, cleaning
 265         cleaning = True
 266         if downtmp: caller.hook_cleanup()
 267         cleaning = False
 268         downtmp = False
 269
 270 def error_cleanup():
 271         try:
 272                 ok = False
 273                 try:
 274                         cleanup()
 275                         ok = True
 276                 except Quit, q:
 277                         print >> sys.stderr, q.m
 278                 except:
 279                         print >> sys.stderr, "Unexpected cleanup error:"
 280                         traceback.print_exc()
 281                         print >> sys.stderr, ''
 282                 if not ok:
 283                         print >> sys.stderr, ("while cleaning up"
 284                                 " because of another error:")
 285         except:
 286                 pass
 287
 288 def prepare():
 289         global downtmp, cleaning
 290         downtmp = None
 291         signal_list = [ signal.SIGHUP, signal.SIGTERM,
 292                         signal.SIGINT, signal.SIGPIPE ]
 293         def sethandlers(f):
 294                 for signum in signal_list: signal.signal(signum, f)
 295         def handler(sig, *any):
 296                 sethandlers(signal.SIG_DFL)
 297                 cleanup()
 298                 os.kill(os.getpid(), sig)
 299         sethandlers(handler)
 300
 301 def mainloop():
 302         try:
 303                 while True: command()
 304         except Quit, q:
 305                 error_cleanup()
 306                 if q.m: print >> sys.stderr, q.m
 307                 sys.exit(q.ec)
 308         except:
 309                 error_cleanup()
 310                 print >> sys.stderr, "Unexpected error:"
 311                 traceback.print_exc()
 312                 sys.exit(16)
 313
 314 def main():
 315         debug("down = %s" % string.join(down))
 316         ok()
 317         prepare()
 318         mainloop()