wizard/util.py

   1 import os.path
   2 import os
   3 import subprocess
   4 import pwd
   5 import sys
   6
   7 import wizard
   8
   9 class ChangeDirectory(object):
  10     """Context for temporarily changing directory"""
  11     def __init__(self, dir):
  12         self.dir = dir
  13         self.olddir = None
  14     def __enter__(self):
  15         self.olddir = os.getcwd()
  16         os.chdir(self.dir)
  17     def __exit__(self, *args):
  18         os.chdir(self.olddir)
  19
  20 def dictmap(f, d):
  21     """A map function for dictionaries.  Does not allow changing keys, only
  22     values"""
  23     return dict((k,f(v)) for k,v in d.items())
  24
  25 def get_exception_name(output):
  26     """Reads the stderr output of another Python command and grabs the
  27     fully qualified exception name"""
  28     lines = output.split("\n")
  29     for line in lines[1:]: # skip the "traceback" line
  30         line = line.rstrip()
  31         if line[0] == ' ': continue
  32         if line[-1] == ":":
  33             return line[:-1]
  34         else:
  35             return line
  36
  37 def get_dir_uid(dir):
  38     """Finds the uid of the person who owns this directory."""
  39     return os.stat(dir).st_uid
  40
  41 def get_dir_owner(dir = "."):
  42     """Finds the name of the locker this directory is in."""
  43     return pwd.getpwuid(get_dir_uid(dir)).pw_name
  44
  45 def get_revision():
  46     """Returns the commit ID of the current Wizard install."""
  47     wizard_git = os.path.join(os.path.dirname(os.path.dirname(os.path.abspath(__file__))), ".git")
  48     return subprocess.Popen(["git", "--git-dir=" + wizard_git, "rev-parse", "HEAD"], stdout=subprocess.PIPE).communicate()[0].rstrip()
  49
  50 def get_operator_info():
  51     """Returns tuple of (realname, email) of person who is operating
  52     this script, as told to use by the Kerberos principal name.
  53     Useful for commit messages."""
  54     username = get_operator_name()
  55     hesinfo = subprocess.Popen(["hesinfo", username, "passwd"],stdout=subprocess.PIPE).communicate()[0]
  56     fields = hesinfo.partition(",")[0]
  57     realname = fields.rpartition(":")[2]
  58     return realname, username + "@mit.edu"
  59
  60 def get_operator_git():
  61     """Returns Real Name <username@mit.edu> suitable for use in
  62     Git Something-by: string."""
  63     return "%s <%s>" % get_operator_info()
  64
  65 def get_operator_name():
  66     """Returns username of the person operating this script."""
  67     principal = os.getenv("SSH_GSSAPI_NAME")
  68     if not principal: raise NoOperatorInfo()
  69     instance, _, _ = principal.partition("@")
  70     if instance.endswith("/root"):
  71         username, _, _ = principal.partition("/")
  72     else:
  73         username = instance
  74     return username
  75
  76 def set_operator_env():
  77     try:
  78         op_realname, op_email = get_operator_info()
  79         os.putenv("GIT_COMMITTER_NAME", op_realname)
  80         os.putenv("GIT_COMMITTER_EMAIL", op_email)
  81     except NoOperatorInfo:
  82         pass
  83
  84 def set_author_env():
  85     try:
  86         lockername = get_dir_owner()
  87         os.putenv("GIT_AUTHOR_NAME", "%s locker" % lockername)
  88         os.putenv("GIT_AUTHOR_EMAIL", "%s@scripts.mit.edu" % lockername)
  89     except KeyError:
  90         pass
  91
  92 def set_git_env():
  93     set_operator_env()
  94     set_author_env()
  95
  96 def get_git_footer():
  97     return "\n".join(["Wizard-revision: %s" % get_revision()
  98         ,"Wizard-args: %s" % " ".join(sys.argv)
  99         ])
 100
 101 class Error(wizard.Error):
 102     pass
 103
 104 class NoOperatorInfo(Error):
 105     pass
 106