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