1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
# Copyright (c) 2015, Ralf Jung <post@ralfj.de>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
# list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#==============================================================================
import sys, os, os.path, subprocess
import configparser, itertools, re
import hmac, hashlib
import email.mime.text, email.utils, smtplib
mail_sender = "null@localhost"
config_file = os.path.join(os.path.dirname(__file__), 'git-mirror.conf')
class GitCommand:
def __getattr__(self, name):
def call(*args, capture_stderr = False, check = True):
'''If <capture_stderr>, return stderr merged with stdout. Otherwise, return stdout and forward stderr to our own.
If <check> is true, throw an exception of the process fails with non-zero exit code. Otherwise, do not.
In any case, return a pair of the captured output and the exit code.'''
cmd = ["git", name.replace('_', '-')] + list(args)
with subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT if capture_stderr else sys.stderr) as p:
(stdout, stderr) = p.communicate()
assert stderr is None
code = p.returncode
if check and code:
raise Exception("Error running {}: Non-zero exit code".format(cmd))
return (stdout.decode('utf-8').strip('\n'), code)
return call
git = GitCommand()
git_nullsha = 40*"0"
def git_is_forced_update(oldsha, newsha):
out, code = git.merge_base("--is-ancestor", oldsha, newsha, check = False) # "Check if the first <commit> is an ancestor of the second <commit>"
assert not out
assert code in (0, 1)
return False if code == 0 else True # if oldsha is an ancestor of newsha, then this was a "good" (non-forced) update
def read_config(defSection = 'DEFAULT'):
'''Reads a config file that may have options outside of any section.'''
config = configparser.ConfigParser()
with open(config_file) as file:
stream = itertools.chain(("["+defSection+"]\n",), file)
config.read_file(stream)
return config
def send_mail(subject, text, recipients, sender, replyTo = None):
assert isinstance(recipients, list)
if not len(recipients): return # nothing to do
# construct content
msg = email.mime.text.MIMEText(text.encode('UTF-8'), 'plain', 'UTF-8')
msg['Subject'] = subject
msg['Date'] = email.utils.formatdate(localtime=True)
msg['From'] = sender
msg['To'] = ', '.join(recipients)
if replyTo is not None:
msg['Reply-To'] = replyTo
# put into envelope and send
s = smtplib.SMTP('localhost')
s.sendmail(sender, recipients, msg.as_string())
s.quit()
class Repo:
def __init__(self, name, conf):
'''Creates a repository from a section of the git-mirror configuration file'''
self.name = name
self.local = conf['local']
self.owner = conf['owner'] # email address to notify in case of problems
self.hmac_secret = conf['hmac-secret'].encode('utf-8')
self.deploy_key = conf['deploy-key'] # the SSH ky used for authenticating against remote hosts
self.mirrors = {} # maps mirrors to their URLs
mirror_prefix = 'mirror-'
for name in filter(lambda s: s.startswith(mirror_prefix), conf.keys()):
mirror = name[len(mirror_prefix):]
self.mirrors[mirror] = conf[name]
def mail_owner(self, msg):
global mail_sender
send_mail("git-mirror {}".format(self.name), msg, recipients = [self.owner], sender = mail_sender)
def compute_hmac(self, data):
h = hmac.new(self.hmac_secret, digestmod = hashlib.sha1)
h.update(data)
return h.hexdigest()
def find_mirror_by_url(self, match_urls):
for mirror, url in self.mirrors.items():
if url in match_urls:
return mirror
return None
def setup_env(self):
'''Setup the environment to work with this repository'''
os.chdir(self.local)
ssh_set_ident = os.path.join(os.path.dirname(__file__), 'ssh-set-ident.sh')
os.putenv('GIT_SSH', ssh_set_ident)
ssh_ident = os.path.join(os.path.expanduser('~/.ssh'), self.deploy_key)
os.putenv('GIT_MIRROR_SSH_IDENT', ssh_ident)
def update_mirrors(self, ref, oldsha, newsha):
'''Update the <ref> from <oldsha> to <newsha> on all mirrors. The update must already have happened locally.'''
assert len(oldsha) == 40 and len(newsha) == 40, "These are not valid SHAs."
source_mirror = os.getenv("GIT_MIRROR_SOURCE") # in case of a self-call via the hooks, we can skip one of the mirrors
self.setup_env()
# check for a forced update
is_forced = newsha != git_nullsha and oldsha != git_nullsha and git_is_forced_update(oldsha, newsha)
# tell all the mirrors
for mirror in self.mirrors:
if mirror == source_mirror:
continue
sys.stdout.write("Updating mirror {}\n".format(mirror)); sys.stdout.flush()
# update this mirror
if is_forced:
# forcibly update ref remotely (someone already did a force push and hence accepted data loss)
git.push('--force', self.mirrors[mirror], newsha+":"+ref)
else:
# nicely update ref remotely (this avoids data loss due to race conditions)
git.push(self.mirrors[mirror], newsha+":"+ref)
def update_ref_from_mirror(self, ref, oldsha, newsha, mirror, suppress_stderr = False):
'''Update the local version of this <ref> to what's currently on the given <mirror>. <oldsha> and <newsha> are checked. Then update all the other mirrors.'''
self.setup_env()
url = self.mirrors[mirror]
# first check whether the remote really is at newsha
remote_state, code = git.ls_remote(url, ref)
if remote_state:
remote_sha = remote_state.split()[0]
else:
remote_sha = git_nullsha
assert newsha == remote_sha, "Someone lied about the new SHA, which should be {}.".format(newsha)
# locally, we have to be at oldsha or newsha (the latter can happen if we already got this update, e.g. if it originated from us)
local_state, code = git.show_ref(ref, check=False)
if code == 0:
local_sha = local_state.split()[0]
else:
if len(local_state):
raise Exception("Something went wrong getting the local state of {}.".format(ref))
local_sha = git_nullsha
# some sanity checking, but deal gracefully with new branches appearing
assert local_sha in (git_nullsha, oldsha, newsha), "Someone lied about the old SHA: Local ({}) is neither old ({}) nor new ({})".format(local_sha, oldsha, newsha)
# if we are already at newsha locally, we also ran the local hooks, so we do not have to do anything
if local_sha == newsha:
return "Local repository is already up-to-date."
# update local state from local_sha to newsha.
if newsha != git_nullsha:
# We *could* now fetch the remote ref and immediately update the local one. However, then we would have to
# decide whether we want to allow a force-update or not. Also, the ref could already have changed remotely,
# so that may update to some other commit.
# Instead, we just fetch without updating any local ref. If the remote side changed in such a way that
# <newsha> is not actually fetched, that's a race and will be noticed when updating the local ref.
git.fetch(url, ref, capture_stderr = suppress_stderr)
# now update the ref, checking the old value is still local_oldsha.
git.update_ref(ref, newsha, 40*"0" if local_sha is None else local_sha)
else:
# ref does not exist anymore. delete it.
assert local_sha != git_nullsha, "Why didn't we bail out earlier if there is nothing to do...?"
#git.update_ref("-d", ref, local_sha) # this checks that the old value is still local_sha
# Now run the post-receive hooks. This will *also* push the changes to all mirrors, as we
# are one of these hooks!
os.putenv("GIT_MIRROR_SOURCE", mirror) # tell ourselves which repo we do *not* have to update
with subprocess.Popen(['/bin/sh', 'hooks/post-receive'], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT) as p:
(stdout, stderr) = p.communicate("{} {} {}\n".format(oldsha, newsha, ref).encode('utf-8'))
stdout = stdout.decode('utf-8')
if p.returncode:
raise Exception("post-receive git hook terminated with non-zero exit code {}:\n{}".format(p.returncode, stdout))
return stdout
def find_repo_by_directory(repos, dir):
for (name, repo) in repos.items():
if dir == repo.local:
return name
return None
def load_repos():
global mail_sender
conf = read_config()
mail_sender = conf['DEFAULT']['mail-sender']
repos = {}
for name, section in conf.items():
if name != 'DEFAULT':
repos[name] = Repo(name, section)
return repos
|
