Add 'sshkey' context manager

MANIFEST.in

@@ -4,7 +4,7 @@ include CHANGES
 include AUTHORS
 include README
 include requirements.txt
+include scripts/ssh_wrapper.py
 
 graft git/test/fixtures
 graft git/test/performance
-

doc/source/tutorial.rst

@@ -383,6 +383,12 @@ You can easily access configuration information for a remote by accessing option
 Change configuration for a specific remote only::
 
  o.config_writer.set("pushurl", "other_url")
+
+You can also specify an SSH key to use for any operations on the remotes:
+
+ private_key_file = project_dir+'id_rsa_deployment_key'
+ with repo.git.sshkey(private_key_file):
+ o.fetch()
 
 
 Submodule Handling

git/cmd.py

@@ -5,13 +5,15 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
 import os
+import os.path
 import sys
 import select
 import logging
 import threading
 import errno
 import mmap
 
+from contextlib import contextmanager
 from subprocess import (
  call,
  Popen,
@@ -139,7 +141,7 @@ def deplete_buffer(fno, handler, buf_list, wg=None):
 
  if hasattr(select, 'poll'):
  # poll is preferred, as select is limited to file handles up to 1024 ... . This could otherwise be
- # an issue for us, as it matters how many handles or own process has
+ # an issue for us, as it matters how many handles our own process has
  poll = select.poll()
  READ_ONLY = select.POLLIN | select.POLLPRI | select.POLLHUP | select.POLLERR
  CLOSED = select.POLLHUP | select.POLLERR
@@ -223,7 +225,7 @@ class Git(LazyMixin):
  Set its value to 'full' to see details about the returned values.
  """
  __slots__ = ("_working_dir", "cat_file_all", "cat_file_header", "_version_info",
- "_git_options")
+ "_git_options", "_environment")
 
  # CONFIGURATION
  # The size in bytes read from stdout when copying git's output to another stream
@@ -413,6 +415,9 @@ def __init__(self, working_dir=None):
  self._working_dir = working_dir
  self._git_options = ()
 
+ # Extra environment variables to pass to git commands
+ self._environment ={}
+
  # cached command slots
  self.cat_file_header = None
  self.cat_file_all = None
@@ -536,6 +541,8 @@ def execute(self, command,
  # Start the process
  env = os.environ.copy()
  env["LC_MESSAGES"] = "C"
+ env.update(self._environment)
+
  proc = Popen(command,
  env=env,
  cwd=cwd,
@@ -608,6 +615,76 @@ def as_text(stdout_value):
  else:
  return stdout_value
 
+ def environment(self):
+ return self._environment
+
+ def update_environment(self, **kwargs):
+ """
+ Set environment variables for future git invocations. Return all changed
+ values in a format that can be passed back into this function to revert
+ the changes:
+
+ ``Examples``::
+
+ old_env = self.update_environment(PWD='/tmp')
+ self.update_environment(**old_env)
+
+ :param kwargs: environment variables to use for git processes
+ :return: dict that maps environment variables to their old values
+ """
+ old_env ={}
+ for key, value in kwargs.iteritems():
+ # set value if it is None
+ if value is not None:
+ if key in self._environment:
+ old_env[key] = self._environment[key]
+ else:
+ old_env[key] = None
+ self._environment[key] = value
+ # remove key from environment if its value is None
+ elif key in self._environment:
+ old_env[key] = self._environment[key]
+ del self._environment[key]
+ return old_env
+
+ @contextmanager
+ def with_environment(self, **kwargs):
+ """
+ A context manager around the above update_environment to restore the
+ environment back to its previous state after operation.
+
+ ``Examples``::
+
+ with self.with_environment(GIT_SSH='/bin/ssh_wrapper'):
+ repo.remotes.origin.fetch()
+
+ :param kwargs: see update_environment
+ """
+ old_env = self.update_environment(**kwargs)
+ try:
+ yield
+ finally:
+ self.update_environment(**old_env)
+
+ @contextmanager
+ def sshkey(self, sshkey_file):
+ """
+ A context manager to temporarily set an SSH key for all operations that
+ run inside it.
+
+ ``Examples``::
+
+ with self.environment(GIT_SSH=project_dir+'deployment_key'):
+ repo.remotes.origin.fetch()
+
+ :param sshkey_file: Path to a private SSH key file
+ """
+ this_dir = os.path.dirname(__file__)
+ ssh_wrapper = os.path.join(this_dir, '..', 'scripts', 'ssh_wrapper.py')
+
+ with self.with_environment(GIT_SSH_KEY_FILE=sshkey_file, GIT_SSH=ssh_wrapper):
+ yield
+
  def transform_kwargs(self, split_single_char_options=False, **kwargs):
  """Transforms Python style kwargs into git command line options."""
  args = list()
@@ -731,7 +808,7 @@ def make_call():
  import warnings
  msg = "WARNING: Automatically switched to use git.cmd as git executable"
  msg += ", which reduces performance by ~70%."
- msg += "Its recommended to put git.exe into the PATH or to "
+ msg += "It is recommended to put git.exe into the PATH or to "
  msg += "set the %s " % self._git_exec_env_var
  msg += "environment variable to the executable's location"
  warnings.warn(msg)

git/remote.py

@@ -354,7 +354,7 @@ def __init__(self, repo, name):
  # that it has the config_writer property, but instead calls __getattr__
  # which will not yield the expected results. 'pinging' the members
  # with a dir call creates the config_writer property that we require
- # ... bugs like these make me wonder wheter python really wants to be used
+ # ... bugs like these make me wonder whether python really wants to be used
  # for production. It doesn't happen on linux though.
  dir(self)
  # END windows special handling

git/test/test_git.py

@@ -153,3 +153,23 @@ def test_env_vars_passed_to_git(self):
  editor = 'non_existant_editor'
  with mock.patch.dict('os.environ',{'GIT_EDITOR': editor}):
  assert self.git.var("GIT_EDITOR") == editor
+
+ def test_environment(self):
+ # sanity check
+ assert self.git.environment() =={}
+
+ # make sure the context manager works and cleans up after itself
+ with self.git.with_environment(PWD='/tmp'):
+ assert self.git.environment() =={'PWD': '/tmp'}
+
+ assert self.git.environment() =={}
+
+ old_env = self.git.update_environment(VARKEY='VARVALUE')
+ # The returned dict can be used to revert the change, hence why it has
+ # an entry with value 'None'.
+ assert old_env =={'VARKEY': None}
+ assert self.git.environment() =={'VARKEY': 'VARVALUE'}
+
+ new_env = self.git.update_environment(**old_env)
+ assert new_env =={'VARKEY': 'VARVALUE'}
+ assert self.git.environment() =={}

git/test/test_remote.py

@@ -163,11 +163,11 @@ def fetch_and_test(remote, **kwargs):
  def get_info(res, remote, name):
  return res["%s/%s" % (remote, name)]
 
- # put remote head to master as it is garantueed to exist
+ # put remote head to master as it is guaranteed to exist
  remote_repo.head.reference = remote_repo.heads.master
 
  res = fetch_and_test(remote)
- # all uptodate
+ # all up to date
  for info in res:
  assert info.flags & info.HEAD_UPTODATE
 

scripts/ssh_wrapper.py

@@ -0,0 +1,9 @@
+#!/usr/bin/env python
+
+importos
+importsubprocess
+importsys
+
+ssh_options= ['-i', os.environ['GIT_SSH_KEY_FILE']]
+ret_code=subprocess.call(['ssh'] +ssh_options+sys.argv[1:])
+sys.exit(ret_code)