dash/contrib/devtools/github-merge.py
2017-05-02 21:12:36 +02:00

333 lines
14 KiB
Python
Executable File

#!/usr/bin/env python3
# Copyright (c) 2016-2017 Bitcoin Core Developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
# This script will locally construct a merge commit for a pull request on a
# github repository, inspect it, sign it and optionally push it.
# The following temporary branches are created/overwritten and deleted:
# * pull/$PULL/base (the current master we're merging onto)
# * pull/$PULL/head (the current state of the remote pull request)
# * pull/$PULL/merge (github's merge)
# * pull/$PULL/local-merge (our merge)
# In case of a clean merge that is accepted by the user, the local branch with
# name $BRANCH is overwritten with the merged result, and optionally pushed.
from __future__ import division,print_function,unicode_literals
import os
from sys import stdin,stdout,stderr
import argparse
import hashlib
import subprocess
import json,codecs
try:
from urllib.request import Request,urlopen
except:
from urllib2 import Request,urlopen
# External tools (can be overridden using environment)
GIT = os.getenv('GIT','git')
BASH = os.getenv('BASH','bash')
# OS specific configuration for terminal attributes
ATTR_RESET = ''
ATTR_PR = ''
COMMIT_FORMAT = '%h %s (%an)%d'
if os.name == 'posix': # if posix, assume we can use basic terminal escapes
ATTR_RESET = '\033[0m'
ATTR_PR = '\033[1;36m'
COMMIT_FORMAT = '%C(bold blue)%h%Creset %s %C(cyan)(%an)%Creset%C(green)%d%Creset'
def git_config_get(option, default=None):
'''
Get named configuration option from git repository.
'''
try:
return subprocess.check_output([GIT,'config','--get',option]).rstrip().decode('utf-8')
except subprocess.CalledProcessError as e:
return default
def retrieve_pr_info(repo,pull):
'''
Retrieve pull request information from github.
Return None if no title can be found, or an error happens.
'''
try:
req = Request("https://api.github.com/repos/"+repo+"/pulls/"+pull)
result = urlopen(req)
reader = codecs.getreader('utf-8')
obj = json.load(reader(result))
return obj
except Exception as e:
print('Warning: unable to retrieve pull information from github: %s' % e)
return None
def ask_prompt(text):
print(text,end=" ",file=stderr)
stderr.flush()
reply = stdin.readline().rstrip()
print("",file=stderr)
return reply
def get_symlink_files():
files = sorted(subprocess.check_output([GIT, 'ls-tree', '--full-tree', '-r', 'HEAD']).splitlines())
ret = []
for f in files:
if (int(f.decode('utf-8').split(" ")[0], 8) & 0o170000) == 0o120000:
ret.append(f.decode('utf-8').split("\t")[1])
return ret
def tree_sha512sum(commit='HEAD'):
# request metadata for entire tree, recursively
files = []
blob_by_name = {}
for line in subprocess.check_output([GIT, 'ls-tree', '--full-tree', '-r', commit]).splitlines():
name_sep = line.index(b'\t')
metadata = line[:name_sep].split() # perms, 'blob', blobid
assert(metadata[1] == b'blob')
name = line[name_sep+1:]
files.append(name)
blob_by_name[name] = metadata[2]
files.sort()
# open connection to git-cat-file in batch mode to request data for all blobs
# this is much faster than launching it per file
p = subprocess.Popen([GIT, 'cat-file', '--batch'], stdout=subprocess.PIPE, stdin=subprocess.PIPE)
overall = hashlib.sha512()
for f in files:
blob = blob_by_name[f]
# request blob
p.stdin.write(blob + b'\n')
p.stdin.flush()
# read header: blob, "blob", size
reply = p.stdout.readline().split()
assert(reply[0] == blob and reply[1] == b'blob')
size = int(reply[2])
# hash the blob data
intern = hashlib.sha512()
ptr = 0
while ptr < size:
bs = min(65536, size - ptr)
piece = p.stdout.read(bs)
if len(piece) == bs:
intern.update(piece)
else:
raise IOError('Premature EOF reading git cat-file output')
ptr += bs
dig = intern.hexdigest()
assert(p.stdout.read(1) == b'\n') # ignore LF that follows blob data
# update overall hash with file hash
overall.update(dig.encode("utf-8"))
overall.update(" ".encode("utf-8"))
overall.update(f)
overall.update("\n".encode("utf-8"))
p.stdin.close()
if p.wait():
raise IOError('Non-zero return value executing git cat-file')
return overall.hexdigest()
def print_merge_details(pull, title, branch, base_branch, head_branch):
print('%s#%s%s %s %sinto %s%s' % (ATTR_RESET+ATTR_PR,pull,ATTR_RESET,title,ATTR_RESET+ATTR_PR,branch,ATTR_RESET))
subprocess.check_call([GIT,'log','--graph','--topo-order','--pretty=format:'+COMMIT_FORMAT,base_branch+'..'+head_branch])
def parse_arguments():
epilog = '''
In addition, you can set the following git configuration variables:
githubmerge.repository (mandatory),
user.signingkey (mandatory),
githubmerge.host (default: git@github.com),
githubmerge.branch (no default),
githubmerge.testcmd (default: none).
'''
parser = argparse.ArgumentParser(description='Utility to merge, sign and push github pull requests',
epilog=epilog)
parser.add_argument('pull', metavar='PULL', type=int, nargs=1,
help='Pull request ID to merge')
parser.add_argument('branch', metavar='BRANCH', type=str, nargs='?',
default=None, help='Branch to merge against (default: githubmerge.branch setting, or base branch for pull, or \'master\')')
return parser.parse_args()
def main():
# Extract settings from git repo
repo = git_config_get('githubmerge.repository')
host = git_config_get('githubmerge.host','git@github.com')
opt_branch = git_config_get('githubmerge.branch',None)
testcmd = git_config_get('githubmerge.testcmd')
signingkey = git_config_get('user.signingkey')
if repo is None:
print("ERROR: No repository configured. Use this command to set:", file=stderr)
print("git config githubmerge.repository <owner>/<repo>", file=stderr)
exit(1)
if signingkey is None:
print("ERROR: No GPG signing key set. Set one using:",file=stderr)
print("git config --global user.signingkey <key>",file=stderr)
exit(1)
host_repo = host+":"+repo # shortcut for push/pull target
# Extract settings from command line
args = parse_arguments()
pull = str(args.pull[0])
# Receive pull information from github
info = retrieve_pr_info(repo,pull)
if info is None:
exit(1)
title = info['title'].strip()
# precedence order for destination branch argument:
# - command line argument
# - githubmerge.branch setting
# - base branch for pull (as retrieved from github)
# - 'master'
branch = args.branch or opt_branch or info['base']['ref'] or 'master'
# Initialize source branches
head_branch = 'pull/'+pull+'/head'
base_branch = 'pull/'+pull+'/base'
merge_branch = 'pull/'+pull+'/merge'
local_merge_branch = 'pull/'+pull+'/local-merge'
devnull = open(os.devnull,'w')
try:
subprocess.check_call([GIT,'checkout','-q',branch])
except subprocess.CalledProcessError as e:
print("ERROR: Cannot check out branch %s." % (branch), file=stderr)
exit(3)
try:
subprocess.check_call([GIT,'fetch','-q',host_repo,'+refs/pull/'+pull+'/*:refs/heads/pull/'+pull+'/*'])
except subprocess.CalledProcessError as e:
print("ERROR: Cannot find pull request #%s on %s." % (pull,host_repo), file=stderr)
exit(3)
try:
subprocess.check_call([GIT,'log','-q','-1','refs/heads/'+head_branch], stdout=devnull, stderr=stdout)
except subprocess.CalledProcessError as e:
print("ERROR: Cannot find head of pull request #%s on %s." % (pull,host_repo), file=stderr)
exit(3)
try:
subprocess.check_call([GIT,'log','-q','-1','refs/heads/'+merge_branch], stdout=devnull, stderr=stdout)
except subprocess.CalledProcessError as e:
print("ERROR: Cannot find merge of pull request #%s on %s." % (pull,host_repo), file=stderr)
exit(3)
try:
subprocess.check_call([GIT,'fetch','-q',host_repo,'+refs/heads/'+branch+':refs/heads/'+base_branch])
except subprocess.CalledProcessError as e:
print("ERROR: Cannot find branch %s on %s." % (branch,host_repo), file=stderr)
exit(3)
subprocess.check_call([GIT,'checkout','-q',base_branch])
subprocess.call([GIT,'branch','-q','-D',local_merge_branch], stderr=devnull)
subprocess.check_call([GIT,'checkout','-q','-b',local_merge_branch])
try:
# Go up to the repository's root.
toplevel = subprocess.check_output([GIT,'rev-parse','--show-toplevel']).strip()
os.chdir(toplevel)
# Create unsigned merge commit.
if title:
firstline = 'Merge #%s: %s' % (pull,title)
else:
firstline = 'Merge #%s' % (pull,)
message = firstline + '\n\n'
message += subprocess.check_output([GIT,'log','--no-merges','--topo-order','--pretty=format:%h %s (%an)',base_branch+'..'+head_branch]).decode('utf-8')
try:
subprocess.check_call([GIT,'merge','-q','--commit','--no-edit','--no-ff','-m',message.encode('utf-8'),head_branch])
except subprocess.CalledProcessError as e:
print("ERROR: Cannot be merged cleanly.",file=stderr)
subprocess.check_call([GIT,'merge','--abort'])
exit(4)
logmsg = subprocess.check_output([GIT,'log','--pretty=format:%s','-n','1']).decode('utf-8')
if logmsg.rstrip() != firstline.rstrip():
print("ERROR: Creating merge failed (already merged?).",file=stderr)
exit(4)
symlink_files = get_symlink_files()
for f in symlink_files:
print("ERROR: File %s was a symlink" % f)
if len(symlink_files) > 0:
exit(4)
# Put tree SHA512 into the message
try:
first_sha512 = tree_sha512sum()
message += '\n\nTree-SHA512: ' + first_sha512
except subprocess.CalledProcessError as e:
printf("ERROR: Unable to compute tree hash")
exit(4)
try:
subprocess.check_call([GIT,'commit','--amend','-m',message.encode('utf-8')])
except subprocess.CalledProcessError as e:
printf("ERROR: Cannot update message.",file=stderr)
exit(4)
print_merge_details(pull, title, branch, base_branch, head_branch)
print()
# Run test command if configured.
if testcmd:
if subprocess.call(testcmd,shell=True):
print("ERROR: Running %s failed." % testcmd,file=stderr)
exit(5)
# Show the created merge.
diff = subprocess.check_output([GIT,'diff',merge_branch+'..'+local_merge_branch])
subprocess.check_call([GIT,'diff',base_branch+'..'+local_merge_branch])
if diff:
print("WARNING: merge differs from github!",file=stderr)
reply = ask_prompt("Type 'ignore' to continue.")
if reply.lower() == 'ignore':
print("Difference with github ignored.",file=stderr)
else:
exit(6)
else:
# Verify the result manually.
print("Dropping you on a shell so you can try building/testing the merged source.",file=stderr)
print("Run 'git diff HEAD~' to show the changes being merged.",file=stderr)
print("Type 'exit' when done.",file=stderr)
if os.path.isfile('/etc/debian_version'): # Show pull number on Debian default prompt
os.putenv('debian_chroot',pull)
subprocess.call([BASH,'-i'])
second_sha512 = tree_sha512sum()
if first_sha512 != second_sha512:
print("ERROR: Tree hash changed unexpectedly",file=stderr)
exit(8)
# Sign the merge commit.
print_merge_details(pull, title, branch, base_branch, head_branch)
while True:
reply = ask_prompt("Type 's' to sign off on the above merge, or 'x' to reject and exit.").lower()
if reply == 's':
try:
subprocess.check_call([GIT,'commit','-q','--gpg-sign','--amend','--no-edit'])
break
except subprocess.CalledProcessError as e:
print("Error signing, exiting.",file=stderr)
exit(1)
elif reply == 'x':
print("Not signing off on merge, exiting.",file=stderr)
exit(1)
# Put the result in branch.
subprocess.check_call([GIT,'checkout','-q',branch])
subprocess.check_call([GIT,'reset','-q','--hard',local_merge_branch])
finally:
# Clean up temporary branches.
subprocess.call([GIT,'checkout','-q',branch])
subprocess.call([GIT,'branch','-q','-D',head_branch],stderr=devnull)
subprocess.call([GIT,'branch','-q','-D',base_branch],stderr=devnull)
subprocess.call([GIT,'branch','-q','-D',merge_branch],stderr=devnull)
subprocess.call([GIT,'branch','-q','-D',local_merge_branch],stderr=devnull)
# Push the result.
while True:
reply = ask_prompt("Type 'push' to push the result to %s, branch %s, or 'x' to exit without pushing." % (host_repo,branch)).lower()
if reply == 'push':
subprocess.check_call([GIT,'push',host_repo,'refs/heads/'+branch])
break
elif reply == 'x':
exit(1)
if __name__ == '__main__':
main()