--- /dev/null
+import sys, os, subprocess
+import configparser, itertools, json, re
+import email.mime.text, email.utils, smtplib
+
+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 None) as p:
+ (stdout, stderr) = p.communicate()
+ assert stderr is None
+ code = p.returncode
+ if check and code:
+ raise Exception("Error running {0}: 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(fname, defSection = 'DEFAULT'):
+ '''Reads a config file that may have options outside of any section.'''
+ config = configparser.ConfigParser()
+ with open(fname) as file:
+ stream = itertools.chain(("["+defSection+"]\n",), file)
+ config.read_file(stream)
+ return config
+
+def send_mail(subject, text, receivers, sender='post+webhook@ralfj.de', replyTo=None):
+ assert isinstance(receivers, list)
+ if not len(receivers): 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(receivers)
+ if replyTo is not None:
+ msg['Reply-To'] = replyTo
+ # put into envelope and send
+ s = smtplib.SMTP('localhost')
+ s.sendmail(sender, receivers, msg.as_string())
+ s.quit()
+
+def get_github_payload():
+ '''Reeturn the github-style JSON encoded payload (as if we were called as a github webhook)'''
+ try:
+ data = sys.stdin.buffer.read()
+ data = json.loads(data.decode('utf-8'))
+ return data
+ except:
+ return {} # nothing read
+
+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.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):
+ send_mail("git-mirror {0}".format(self.name), msg, [self.owner])
+
+ 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 update_mirrors(self, ref, oldsha, newsha, except_mirrors = [], suppress_stderr = False):
+ '''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."
+ os.chdir(self.local)
+ # 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 in except_mirrors:
+ continue
+ # 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, capture_stderr = suppress_stderr)
+ else:
+ # nicely update ref remotely (this avoids data loss due to race conditions)
+ git.push(self.mirrors[mirror], newsha+":"+ref, capture_stderr = suppress_stderr)
+
+ 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.'''
+ os.chdir(self.local)
+ 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 {0}.".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 {0}.".format(ref))
+ local_sha = git_nullsha
+ assert local_sha in (oldsha, newsha), "Someone lied about the old SHA."
+ # 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
+ # 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
+ # update all the mirrors
+ self.update_mirrors(ref, oldsha, newsha, [mirror], suppress_stderr)
+
+def find_repo_by_directory(repos, dir):
+ for (name, repo) in repos.items():
+ if dir == repo.local:
+ return name
+ return None
+
+def load_repos():
+ conffile = os.path.join(os.path.dirname(__file__), 'git-mirror.conf')
+ conf = read_config(conffile)
+ repos = {}
+ for name, section in conf.items():
+ if name != 'DEFAULT':
+ repos[name] = Repo(name, section)
+ return repos
+
projects / git-mirror.git / blobdiff