#!/usr/bin/python3
import sys, os, subprocess, argparse
+import configparser, itertools, json, re
+import traceback
+import email.mime.text, email.utils, smtplib
class GitCommand:
def __getattr__(self, name):
- def call(*args, get_stderr = False):
+ 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)
- output = subprocess.check_output(cmd, stderr=subprocess.STDOUT if get_stderr else None)
- return output.decode('utf-8').strip('\n')
+ 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
-
- def branches(self, *args):
- b = self.branch(*args).split('\n')
- b = map(lambda s: s[2:], b)
- return list(b)
git = GitCommand()
-def is_all_zero(str):
- return len(str.replace('0', '')) == 0
+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, local, mirrors):
- '''<local> is the directory containing the repository locally, <mirrors> a list of remote repositories'''
- self.local = local
- self.mirrors = mirrors
+ def __init__(self, conf):
+ '''Creates a repository from a section of the git-mirror configuration file'''
+ self.local = conf['local']
+ 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]
-# This is old code, that may be useful again if we decide to care about racy pushes loosing commits.
-# def pull(self, slavenr):
-# slave = self.slaves[slavenr]
-# slavename = "slave-"+str(slavenr)
-# # make sure we have the remote
-# try:
-# git.remote("add", slavename, slave, get_stderr=True)
-# except subprocess.CalledProcessError: # the remote already exists
-# git.remote("set-url", slavename, slave)
-# # get all the changes
-# git.fetch(slavename, get_stderr=True)
-# # merge them... or hope so...
-# branches = git.branches("-r")
-# for branch in filter(lambda s: s.startswith(slavename+"/"), branches):
-# local = branch[len(slavename+"/"):]
-# print(local, branch)
+ 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_mirror_ref(self, ref, mirror):
- '''Update <ref> on <mirror> to the local state. If <newsha> is all-zero, the ref should be deleted.'''
- git.push('--force', self.mirrors[mirror], ref)
+ def have_ref(self, ref, url=None):
+ '''Tests if a given ref exists, locally or (if the url is given) remotely'''
+ if url is None:
+ out, code = git.show_ref(ref, check = False)
+ if code and len(out):
+ raise Exception("Checking for a local ref failed")
+ else:
+ out, code = git.ls_remote(url, ref)
+ # the ref exists iff we have output
+ return len(out) > 0
+
+ def update_mirrors(self, ref, delete, exception = None, suppress_stderr = False):
+ '''Update <ref> on all mirrors except for <exception> to the local state, or delete it.'''
+ for mirror in self.mirrors:
+ if mirror == exception:
+ continue
+ # update this mirror
+ if not self.have_ref(ref):
+ # delete ref remotely
+ git.push(self.mirrors[mirror], ':'+ref, capture_stderr = suppress_stderr)
+ else:
+ # update ref remotely
+ git.push('--force', self.mirrors[mirror], ref, capture_stderr = suppress_stderr)
- def update_ref(self, newsha, ref, source):
- '''Update the <ref> to <newsha> everywhere. <source> is None if this update comes from the local repository,
- or the name of a mirror. If <newsha> is all-zero, the ref should be deleted.'''
+ def update_ref(self, ref, source, suppress_stderr = False):
+ '''Update the <ref> to its state in <source> everywhere. <source> is None to refer to the local repository,
+ or the name of a mirror.'''
os.chdir(self.local)
if source is None:
# We already have the latest version locally. Update all the mirrors.
- for mirror in self.mirrors:
- self.update_mirror_ref(ref, mirror)
+ self.update_mirrors(ref, delete = not self.have_ref(ref), suppress_stderr = suppress_stderr)
else:
- raise Exception("Help, what should I do?")
+ # update our version of this ref. This may fail if the ref does not exist anymore.
+ url = self.mirrors[source]
+ if not self.have_ref(ref, url):
+ # delete ref locally
+ git.update_ref("-d", ref)
+ # and everywhere (except for the source)
+ self.update_mirrors(ref, delete = True, exception = source, suppress_stderr = suppress_stderr)
+ else:
+ # update local ref to remote state (yes, there's a race condition here - the ref could no longer exist by now)
+ git.fetch(url, ref+":"+ref)
+ # and everywhere else
+ self.update_mirrors(ref, delete = False, exception = source, suppress_stderr = suppress_stderr)
-# for now, configuration is hard-coded here...
-
-repos = {
- 'sync-test': Repo('/home/git/repositories/test.git', {'github': 'git@github.com:RalfJung/sync-test.git'}),
-}
-
-def find_repo_by_directory(dir):
+def find_repo_by_directory(repos, dir):
for (name, repo) in repos.items():
if dir == repo.local:
return name
if __name__ == "__main__":
parser = argparse.ArgumentParser(description='Keep git repositories in sync')
- parser.add_argument("--hook",
- action="store_true", dest="hook",
- help="Act as git hook: Auto-detect the repository based on the working directoy, and fetch information from stdin")
+ parser.add_argument("--git-hook",
+ action="store_true", dest="git_hook",
+ help="Act as git hook: Auto-detect the repository based on the working directoy, and fetch information from stdin the way git encodes it")
+ parser.add_argument("--web-hook",
+ action="store_true", dest="web_hook",
+ help="Act as github-style web hook: Repository has to be given explicitly, all the rest is read from stdin JSON form")
parser.add_argument("-r", "--repository",
dest="repository",
help="The name of the repository to act on")
args = parser.parse_args()
+ if args.git_hook and args.web_hook:
+ raise Exception("I cannot be two hooks at once.")
- reponame = args.repository
- if reponame is None and args.hook:
- reponame = find_repo_by_directory(os.getcwd())
- if reponame is None:
- raise Exception("Unable to detect repository, please use --repository.")
-
- # now sync this repository
- repo = repos[reponame]
- if args.hook:
- # parse the information we get from stdin
- for line in sys.stdin:
- (oldsha, newsha, ref) = line.split()
- repo.update_ref(newsha, ref, source=None)
- else:
- raise Exception("I am unsure what to do here.")
+ try:
+ # All arguments are *untrusted* input, as we may be called via sudo from the webserver. So we fix the configuration file location.
+ 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(section)
+
+ # find the repository we are dealing with
+ reponame = args.repository
+ if reponame is None and args.git_hook:
+ reponame = find_repo_by_directory(repos, os.getcwd())
+ if reponame is None or reponame not in repos:
+ raise Exception("Unknown or missing repository name.")
+
+ # now sync this repository
+ repo = repos[reponame]
+ if args.git_hook:
+ # parse the information we get from stdin
+ for line in sys.stdin:
+ (oldsha, newsha, ref) = line.split()
+ repo.update_ref(ref, source = None)
+ elif args.web_hook:
+ data = get_github_payload()
+ ref = data["ref"]
+ # validate the ref name
+ if re.match('refs/[a-z/]+', ref) is None:
+ raise Exception("Invalid ref name {0}".format(ref))
+ # collect URLs of this repository
+ urls = []
+ for key in ("git_url", "ssh_url", "clone_url"):
+ urls.append(data["repository"][key])
+ source = repo.find_mirror_by_url(urls)
+ if source is None:
+ raise Exception("Could not find the source.")
+ repo.update_ref(ref, source = source, suppress_stderr = True)
+ # print an answer
+ print("Content-Type: text/plain")
+ print()
+ print("Updated {0}:{1} from source {2}".format(reponame, ref, source))
+ else:
+ raise Exception("No manual mode is implemented so far.")
+ except Exception as e:
+ # don't leak filenames etc. when we are running as a hook
+ if args.web_hook:
+ print("Status: 500 Internal Server Error")
+ print("Content-Type: text/plain")
+ print()
+ print(str(e))
+ elif args.git_hook:
+ #sys.stderr.write(str(e))
+ traceback.print_exc()
+ else:
+ traceback.print_exc()