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
  57 def cmd_quit(c, ce):
  58         cmdnumargs(c, ce)
  59         raise Quit(0, '')
  60
  61 def execute_raw(what, instr, *popenargs, **popenargsk):
  62         debug(" ++ %s" % string.join(popenargs[0]))
  63         sp = subprocess.Popen(*popenargs, **popenargsk)
  64         if instr is None: popenargsk['stdin'] = devnull_read
  65         (out, err) = sp.communicate(instr)
  66         if err: bomb("%s unexpectedly produced stderr output `%s'" %
  67                         (what, err))
  68         status = sp.wait()
  69         return (status, out)
  70
  71 def execute(cmd_string, cmd_list=[], downp=False, outp=False):
  72         cmdl = cmd_string.split()
  73
  74         if downp: perhaps_down = down
  75         else: downp = []
  76
  77         if outp: stdout = subprocess.PIPE
  78         else: stdout = None
  79
  80         cmd = cmdl + cmd_list
  81         if len(perhaps_down): cmd = perhaps_down + [' '.join(cmd)]
  82
  83         (status, out) = execute_raw(cmdl[0], None, cmd, stdout=stdout)
  84
  85         if status: bomb("%s%s failed (exit status %d)" %
  86                         ((downp and "(down) " or ""), cmdl[0], status))
  87
  88         if outp and out and out[-1]=='\n': out = out[:-1]
  89         return out
  90
  91 def cmd_open(c, ce):
  92         global downtmp
  93         cmdnumargs(c, ce)
  94         if downtmp: bomb("`open' when already open")
  95         downtmp = caller.hook_open()
  96         return [downtmp]
  97
  98 def cmd_close(c, ce):
  99         global downtmp
 100         cmdnumargs(c, ce)
 101         if not downtmp: bomb("`close' when not open")
 102         cleanup()
 103
 104 def cmd_stop(c, ce):
 105         global downtmp
 106         cmdnumargs(c, ce, 1)
 107         if not downtmp: bomb("`stop' when not open")
 108         caller.hook_stop()
 109         cleanup()
 110
 111 def down_python_script(gobody, functions=''):
 112         # Many things are made much harder by the inability of
 113         # dchroot, ssh, et al, to cope without mangling the arguments.
 114         # So we run a sub-python on the testbed and feed it a script
 115         # on stdin.  The sub-python decodes the arguments.
 116
 117         script = (      "import urllib\n"
 118                         "import os\n"
 119                         "def setfd(fd,fnamee,write,mode=0666):\n"
 120                         "       fname = urllib.unquote(fnamee)\n"
 121                         "       if write: rw = os.O_WRONLY|os.O_CREAT\n"
 122                         "       else: rw = os.O_RDONLY\n"
 123                         "       nfd = os.open(fname, rw, mode)\n"
 124                         "       os.dup2(nfd,fd)\n"
 125                         + functions +
 126                         "def go():\n" )
 127         script += (     "       os.environ['TMPDIR']= urllib.unquote('%s')\n" %
 128                                 urllib.quote(downtmp)   )
 129         script += (     "       os.chdir(os.environ['TMPDIR'])\n" )
 130         script += (     gobody +
 131                         "go()\n" )
 132
 133         debug("+P ...\n"+script)
 134
 135         scripte = urllib.quote(script)
 136         cmdl = down + ['python','-c',
 137                 "'import urllib; s = urllib.unquote(%s); exec s'" %
 138                         ('"%s"' % scripte)]
 139         return cmdl
 140
 141 def cmd_execute(c, ce):
 142         cmdnumargs(c, ce, 5)
 143         gobody = "      import sys\n"
 144         for ioe in range(3):
 145                 gobody += "     setfd(%d,'%s',%d)\n" % (
 146                         ioe, ce[ioe+2], ioe>0 )
 147         gobody += "     os.chdir(urllib.unquote('" + ce[5] +"'))\n"
 148         gobody += "     cmd = '%s'\n" % ce[1]
 149         gobody += ("    cmd = cmd.split(',')\n"
 150                 "       cmd = map(urllib.unquote, cmd)\n"
 151                 "       c0 = cmd[0]\n"
 152                 "       if '/' in c0:\n"
 153                 "               if not os.access(c0, os.X_OK):\n"
 154                 "                       status = os.stat(c0)\n"
 155                 "                       mode = status.st_mode | 0111\n"
 156                 "                       os.chmod(c0, mode)\n"
 157                 "       try: os.execvp(c0, cmd)\n"
 158                 "       except OSError, e:\n"
 159                 "               print >>sys.stderr, \"%s: %s\" % (\n"
 160                 "                       (c0, os.strerror(e.errno)))\n"
 161                 "               os._exit(127)\n")
 162         cmdl = down_python_script(gobody)
 163
 164         (status, out) = execute_raw('sub-python', None, cmdl,
 165                                 stdin=devnull_read, stderr=subprocess.PIPE)
 166         if out: bomb("sub-python unexpected produced stdout"
 167                         " visible to us `%s'" % out)
 168         return [`status`]
 169
 170 def copyupdown(c, ce, upp):
 171         cmdnumargs(c, ce, 2)
 172         isrc = 0
 173         idst = 1
 174         ilocal = 0 + upp
 175         iremote = 1 - upp
 176         wh = ce[0]
 177         sd = c[1:]
 178         sde = ce[1:]
 179         if not sd[0] or not sd[1]:
 180                 bomb("%s paths must be nonempty" % wh)
 181         dirsp = sd[0][-1]=='/'
 182         functions = "import errno\n"
 183         if dirsp != (sd[1][-1]=='/'):
 184                 bomb("% paths must agree about directoryness"
 185                         " (presence or absence of trailing /)" % wh)
 186         localfd = None
 187         deststdout = devnull_read
 188         srcstdin = devnull_read
 189         preexecfns = [None, None]
 190         if not dirsp:
 191                 modestr = ''
 192                 if upp:
 193                         deststdout = file(sd[idst], 'w')
 194                 else:
 195                         srcstdin = file(sd[isrc], 'r')
 196                         status = os.fstat(srcstdin.fileno())
 197                         if status.st_mode & 0111: modestr = ',0777'
 198                 gobody = "      setfd(%s,'%s',%s%s)\n" % (
 199                                         1-upp, sde[iremote], not upp, modestr)
 200                 gobody += "     os.execvp('cat', ['cat'])\n"
 201                 localcmdl = ['cat']
 202         else:
 203                 gobody = "      dir = urllib.unquote('%s')\n" % sde[iremote]
 204                 if upp:
 205                         try: os.mkdir(sd[ilocal])
 206                         except OSError, oe:
 207                                 if oe.errno != errno.EEXIST: raise
 208                 else:
 209                         gobody += ("    try: os.mkdir(dir)\n"
 210                                 "       except OSError, oe:\n"
 211                                 "               if oe.errno != errno.EEXIST: raise\n")
 212                 gobody +=( "    os.chdir(dir)\n"
 213                         "       tarcmd = 'tar -f -'.split()\n")
 214                 localcmdl = 'tar -f -'.split()
 215                 taropts = [None, None]
 216                 taropts[isrc] = '-c .'
 217                 taropts[idst] = '-p -x --no-same-owner'
 218                 gobody += "     tarcmd += '%s'.split()\n" % taropts[iremote]
 219                 localcmdl += ['-C',sd[ilocal]]
 220                 localcmdl += taropts[ilocal].split()
 221                 gobody += "     os.execvp('tar', tarcmd)\n";
 222
 223         downcmdl = down_python_script(gobody, functions)
 224
 225         if upp: cmdls = (downcmdl, localcmdl)
 226         else: cmdls = (localcmdl, downcmdl)
 227
 228         debug(`["cmdls", `cmdls`]`)
 229         debug(`["srcstdin", `srcstdin`, "deststdout", `deststdout`, "devnull_read", devnull_read]`)
 230
 231         subprocs = [None,None]
 232         debug(" +< %s" % string.join(cmdls[0]))
 233         subprocs[0] = subprocess.Popen(cmdls[0], stdin=srcstdin,
 234                         stdout=subprocess.PIPE, preexec_fn=preexecfns[0])
 235         debug(" +> %s" % string.join(cmdls[1]))
 236         subprocs[1] = subprocess.Popen(cmdls[1], stdin=subprocs[0].stdout,
 237                         stdout=deststdout, preexec_fn=preexecfns[1])
 238         for sdn in [1,0]:
 239                 status = subprocs[sdn].wait()
 240                 if status: bomb("%s %s failed, status %d" %
 241                         (wh, ['source','destination'][sdn], status))
 242
 243 def cmd_copydown(c, ce): copyupdown(c, ce, False)
 244 def cmd_copyup(c, ce): copyupdown(c, ce, True)
 245
 246 def command():
 247         sys.stdout.flush()
 248         ce = sys.stdin.readline()
 249         if not ce: bomb('end of file - caller quit?')
 250         ce = ce.rstrip().split()
 251         c = map(urllib.unquote, ce)
 252         if not c: bomb('empty commands are not permitted')
 253         debug('executing '+string.join(ce))
 254         try: f = globals()['cmd_'+c[0]]
 255         except KeyError: bomb("unknown command `%s'" % ce[0])
 256         r = f(c, ce)
 257         if not r: r = []
 258         r.insert(0, 'ok')
 259         ru = map(urllib.quote, r)
 260         print string.join(ru)
 261
 262 def cleanup():
 263         global downtmp, cleaning
 264         cleaning = True
 265         if downtmp: caller.hook_cleanup()
 266         cleaning = False
 267         downtmp = False
 268
 269 def error_cleanup():
 270         try:
 271                 ok = False
 272                 try:
 273                         cleanup()
 274                         ok = True
 275                 except Quit, q:
 276                         print >> sys.stderr, q.m
 277                 except:
 278                         print >> sys.stderr, "Unexpected cleanup error:"
 279                         traceback.print_exc()
 280                         print >> sys.stderr, ''
 281                 if not ok:
 282                         print >> sys.stderr, ("while cleaning up"
 283                                 " because of another error:")
 284         except:
 285                 pass
 286
 287 def prepare():
 288         global downtmp, cleaning
 289         downtmp = None
 290         signal_list = [ signal.SIGHUP, signal.SIGTERM,
 291                         signal.SIGINT, signal.SIGPIPE ]
 292         def sethandlers(f):
 293                 for signum in signal_list: signal.signal(signum, f)
 294         def handler(sig, *any):
 295                 sethandlers(signal.SIG_DFL)
 296                 cleanup()
 297                 os.kill(os.getpid(), sig)
 298         sethandlers(handler)
 299
 300 def mainloop():
 301         try:
 302                 while True: command()
 303         except Quit, q:
 304                 error_cleanup()
 305                 if q.m: print >> sys.stderr, q.m
 306                 sys.exit(q.ec)
 307         except:
 308                 error_cleanup()
 309                 print >> sys.stderr, "Unexpected error:"
 310                 traceback.print_exc()
 311                 sys.exit(16)
 312
 313 def main():
 314         ok()
 315         prepare()
 316         mainloop()