git-mirror/webhook-core.py

#!/usr/bin/python3
# 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
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#==============================================================================

# This is the hook called by GitHub as webhook. It updats the local repository, and then all the other mirrors.
import sys, traceback
from git_mirror import *

if __name__ == "__main__":
    repo = None # we will try to use this during exception handling
    try:
        repos = load_repos()
        reponame = sys.argv[1] if len(sys.argv) > 1 else None
        if reponame not in repos:
            raise Exception("Repository missing or not found.")
        repo = repos[reponame]
        
        # now sync this repository
        data = get_github_payload()
        if 'zen' in data:
            # github sends this initially
            print("Content-Type: text/plain")
            print()
            print("Welcome!")
            sys.exit(0)
        ref = data["ref"]
        oldsha = data["before"]
        newsha = data["after"]
        # 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, to find the mirror name
        urls = []
        for key in ("git_url", "ssh_url", "clone_url"):
            urls.append(data["repository"][key])
        mirror = repo.find_mirror_by_url(urls)
        if mirror is None:
            raise Exception("Could not find the mirror.")
        repo.update_ref_from_mirror(ref, oldsha, newsha, mirror, suppress_stderr = True)
        # print an answer
        print("Content-Type: text/plain")
        print()
        print("Updated {0}:{1} from mirror {2} from {3} to {4}".format(reponame, ref, mirror, oldsha, newsha))
    except Exception as e:
        if repo is not None:
            repo.mail_owner("There was a problem running the git-mirror webhook:\n\n{0}".format(traceback.format_exc()))
        # do not print all the details
        print("Status: 500 Internal Server Error")
        print("Content-Type: text/plain")
        print()
        print("We have a problem:\n{0}".format('\n'.join(traceback.format_exception_only(type(e), e))))