# Copyright (c) 2015, Ralf Jung # 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') def Popen_quirky(cmd, **args): ''' Runs cmd via subprocess.Popen; and if that fails, puts it into the shell (/bin/sh). It seems that's what executing things in bash does, and even execve. Also, all so-far released versions of Gitolite get the shebang line wrong. ''' try: return subprocess.Popen(cmd, **args) except OSError as e: return subprocess.Popen(['/bin/sh'] + cmd, **args) class GitCommand: def __getattr__(self, name): def call(*args, capture_stderr = False, check = True): '''If , return stderr merged with stdout. Otherwise, return stdout and forward stderr to our own. If 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 is an ancestor of the second " 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') if 'hmac-secret' in conf else None 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): assert self.hmac_secret is not None 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 from to 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 to what's currently on the given . and 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 # 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 Popen_quirky(['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