osutil: implement setprocname to set process title for some platforms
This patch adds a simple setprocname method to osutil. The operation is not
defined by any standard and is platform-specific, the current implementation
tries to cover some major platforms (ex. Linux, OS X, FreeBSD) that is
relatively easy to support. Other platforms (Windows [4], other BSDs, ...)
can be added in the future.
The current implementation supports two methods to change process title:
a. setproctitle if available (works in FreeBSD).
b. rewrite argv in place (works in Linux [1] and Mac OS X). [2] [3]
[1]: Linux has "prctl(PR_SET_NAME, ...)" but 1) it has 16-byte limit, which
is too small; 2) it is not quite equivalent to what we want - it changes
"/proc/self/comm", not "/proc/self/cmdline" - "comm" change won't show up
in "ps" output unless "-o comm" is used.
[2]: The implementation does not rewrite the **environ buffer like some
other implementations do, just to make the code simpler and safer. However,
this also means the buffer size we can rewrite is significantly shorter. If
we are really greedy and want the "environ" space, we can change the
implementation later.
[3]: It requires a CPython private API: Py_GetArgcArgv to get the original
argv. Unfortunately Python 3 makes a copy of argv and returns the wchar_t
version, so it is not supported for now. (if we really want to, we could
count backwards from "char **environ", given known argc and argv, not sure
if that's a good idea - probably not)
[4]: The feature is aimed to make it easier for forked command server
processes to show what they are doing. Since Windows does not support
fork(), despite it's a major platform, its support is not added in this
patch.
# Since it's not easy to write a test that portably deals
# with files from different users/groups, we cheat a bit by
# monkey-patching some functions in the util module
from __future__ import absolute_import, print_function
import os
from mercurial import (
error,
ui as uimod,
util,
)
hgrc = os.environ['HGRCPATH']
f = open(hgrc)
basehgrc = f.read()
f.close()
def testui(user='foo', group='bar', tusers=(), tgroups=(),
cuser='foo', cgroup='bar', debug=False, silent=False,
report=True):
# user, group => owners of the file
# tusers, tgroups => trusted users/groups
# cuser, cgroup => user/group of the current process
# write a global hgrc with the list of trusted users/groups and
# some setting so that we can be sure it was read
f = open(hgrc, 'w')
f.write(basehgrc)
f.write('\n[paths]\n')
f.write('global = /some/path\n\n')
if tusers or tgroups:
f.write('[trusted]\n')
if tusers:
f.write('users = %s\n' % ', '.join(tusers))
if tgroups:
f.write('groups = %s\n' % ', '.join(tgroups))
f.close()
# override the functions that give names to uids and gids
def username(uid=None):
if uid is None:
return cuser
return user
util.username = username
def groupname(gid=None):
if gid is None:
return 'bar'
return group
util.groupname = groupname
def isowner(st):
return user == cuser
util.isowner = isowner
# try to read everything
#print '# File belongs to user %s, group %s' % (user, group)
#print '# trusted users = %s; trusted groups = %s' % (tusers, tgroups)
kind = ('different', 'same')
who = ('', 'user', 'group', 'user and the group')
trusted = who[(user in tusers) + 2*(group in tgroups)]
if trusted:
trusted = ', but we trust the ' + trusted
print('# %s user, %s group%s' % (kind[user == cuser], kind[group == cgroup],
trusted))
u = uimod.ui()
u.setconfig('ui', 'debug', str(bool(debug)))
u.setconfig('ui', 'report_untrusted', str(bool(report)))
u.readconfig('.hg/hgrc')
if silent:
return u
print('trusted')
for name, path in u.configitems('paths'):
print(' ', name, '=', path)
print('untrusted')
for name, path in u.configitems('paths', untrusted=True):
print('.', end=' ')
u.config('paths', name) # warning with debug=True
print('.', end=' ')
u.config('paths', name, untrusted=True) # no warnings
print(name, '=', path)
print()
return u
os.mkdir('repo')
os.chdir('repo')
os.mkdir('.hg')
f = open('.hg/hgrc', 'w')
f.write('[paths]\n')
f.write('local = /another/path\n\n')
f.close()
#print '# Everything is run by user foo, group bar\n'
# same user, same group
testui()
# same user, different group
testui(group='def')
# different user, same group
testui(user='abc')
# ... but we trust the group
testui(user='abc', tgroups=['bar'])
# different user, different group
testui(user='abc', group='def')
# ... but we trust the user
testui(user='abc', group='def', tusers=['abc'])
# ... but we trust the group
testui(user='abc', group='def', tgroups=['def'])
# ... but we trust the user and the group
testui(user='abc', group='def', tusers=['abc'], tgroups=['def'])
# ... but we trust all users
print('# we trust all users')
testui(user='abc', group='def', tusers=['*'])
# ... but we trust all groups
print('# we trust all groups')
testui(user='abc', group='def', tgroups=['*'])
# ... but we trust the whole universe
print('# we trust all users and groups')
testui(user='abc', group='def', tusers=['*'], tgroups=['*'])
# ... check that users and groups are in different namespaces
print("# we don't get confused by users and groups with the same name")
testui(user='abc', group='def', tusers=['def'], tgroups=['abc'])
# ... lists of user names work
print("# list of user names")
testui(user='abc', group='def', tusers=['foo', 'xyz', 'abc', 'bleh'],
tgroups=['bar', 'baz', 'qux'])
# ... lists of group names work
print("# list of group names")
testui(user='abc', group='def', tusers=['foo', 'xyz', 'bleh'],
tgroups=['bar', 'def', 'baz', 'qux'])
print("# Can't figure out the name of the user running this process")
testui(user='abc', group='def', cuser=None)
print("# prints debug warnings")
u = testui(user='abc', group='def', cuser='foo', debug=True)
print("# report_untrusted enabled without debug hides warnings")
u = testui(user='abc', group='def', cuser='foo', report=False)
print("# report_untrusted enabled with debug shows warnings")
u = testui(user='abc', group='def', cuser='foo', debug=True, report=False)
print("# ui.readconfig sections")
filename = 'foobar'
f = open(filename, 'w')
f.write('[foobar]\n')
f.write('baz = quux\n')
f.close()
u.readconfig(filename, sections=['foobar'])
print(u.config('foobar', 'baz'))
print()
print("# read trusted, untrusted, new ui, trusted")
u = uimod.ui()
u.setconfig('ui', 'debug', 'on')
u.readconfig(filename)
u2 = u.copy()
def username(uid=None):
return 'foo'
util.username = username
u2.readconfig('.hg/hgrc')
print('trusted:')
print(u2.config('foobar', 'baz'))
print('untrusted:')
print(u2.config('foobar', 'baz', untrusted=True))
print()
print("# error handling")
def assertraises(f, exc=error.Abort):
try:
f()
except exc as inst:
print('raised', inst.__class__.__name__)
else:
print('no exception?!')
print("# file doesn't exist")
os.unlink('.hg/hgrc')
assert not os.path.exists('.hg/hgrc')
testui(debug=True, silent=True)
testui(user='abc', group='def', debug=True, silent=True)
print()
print("# parse error")
f = open('.hg/hgrc', 'w')
f.write('foo')
f.close()
try:
testui(user='abc', group='def', silent=True)
except error.ParseError as inst:
print(inst)
try:
testui(debug=True, silent=True)
except error.ParseError as inst:
print(inst)