pre-receive

#!/usr/bin/env python2.6
# Version 1.0
import sys

"""
Git Push Hook to use with JIRA v4.3.2
"""
__author__ = 'Praful Mathur'
__version__ = '0.1.0'
__license__ = 'BSD'

# GLOBALS
USERNAME = '' # Your JIRA username
PASSWORD = '' # Your JIRA password
git_help = "git rebase -i HEAD~" # changes in push_hook, appends # of commits
first_err = True # changes in git_status_out, used as flag

def git_status_out(msg, err=True):
    """
    Git status out - Output to correct std stream, based on err flag
    String Boolean? ->
    SIDE EFFECTS: Outputs the given msg to (STDOUT | STDERR)
    """
    global first_err
    prepend = ">>>>   "
    output_to = sys.stderr

    if err and first_err:
        first_err = False
        output_to.write(prepend + "-----------------------------------\n")
        output_to.write(prepend + "ERROR: NOTHING IS PUSHED TO REMOTE!\n")
        output_to.write(prepend + "-----------------------------------\n")

    output_to.write(prepend + msg + "\n")

def ticket_status(ticket_number, request_lib):
    """
    Ticket status - Check JIRA that ticket is 'In Progress`
    Uses JIRA API v4.3.2:
    http://confluence.atlassian.com/display/JIRA043/JIRA+Documentation
    String Function -> Boolean
    """
    import json
    (get_method, ConnectionError) = request_lib
    base_url = "https://{jira_url}"
    api_suffix = "/rest/api/latest/issue/"
    url = base_url + api_suffix + ticket_number
    prepend_help = "Commit message fail? Try"

    # set headers for JIRA request
    headers = {'content-type': 'application/json'}
    try:
        req = get_method(url, auth=(USERNAME,PASSWORD), headers=headers)
    except ConnectionError:
        git_status_out("Connection to JIRA timed-out, check Portal")
        return False

    # Check ticket existence
    if req.status_code == 200:
        response = json.loads(req.content)

        # ensure valid response from JIRA
        if response.has_key('fields'):
            ticket_state = response['fields']['status']['value']['name']

            if ticket_state == "In Progress":
                git_status_out("Committing to " + response['self'], err=False)
                return True

            else:
                action = "set to 'In Progress'"
                if ticket_state not in ['Open', 'Reopened']:
                    action = 're-open and ' + action

                git_status_out("Ticket is '%s' please %s -- %s/browse/%s"\
                    %(ticket_state, action, base_url, ticket_number))
                git_status_out("%s `%s`" %(prepend_help, git_help))
        else:
            git_status_out("Malformed JIRA response, please try again.")

    # Auth Error
    elif req.status_code == 401:
        git_status_out("Login to JIRA failed, please contact systems immediately!")

    # Ticket Not Found
    elif req.status_code == 404:
        git_status_out("Ticket does not exist")
        git_status_out("%s `%s`" %(prepend_help, git_help))

    # Unknown Error
    else: 
        git_status_out("Unknown error, please contact systems immediately!")

    return False

def ticket_exception(commit_msg):
    """
    Ticket exception - Commits that can break the JIRA ticket rule
    String -> Boolean
    """
    # add exceptional commit actions (case-sensitive) to whitelist
    whitelist = set(['Revert'])
    action_word = commit_msg.split(' ')[0]
    if action_word in whitelist:
        git_status_out("Ticket is an exception to the JIRA rule, action: %s"
                %(action_word), err=False)
        return True
    return False

def extract_ticket_number(commit_msg):
    """
    Extract ticket number - Ticket is in JIRA format and prepends commit message
    String -> (String | None)
    """
    import re
    ticket_regex = re.compile("^\w+-\d+")
    ticket_match = ticket_regex.match(commit_msg)

    git_status_out("Looking at commit message: '%s'" %(commit_msg), err=False)

    if ticket_match:
        ticket_number = ticket_match.group()
        msg = "Found ticket number: %s" %(ticket_number)
        git_status_out(msg, err=False)
        return ticket_number
    else:
        git_status_out("No ticket number found at beginning of commit message.")
        git_status_out("Example: 'PM-125 - Created a great human being'.")
        git_status_out("`%s` and reword/squash commit message."  
                %(git_help))
        return None

def check_commit(commit_msg, request_lib):
    """
    Check commit - Check given commit_msg has an 'In Progress' ticket
    String Function -> Boolean
    """
    if ticket_exception(commit_msg):
        return True

    ticket_number = extract_ticket_number(commit_msg)
    if ticket_number:
        status = ticket_status(ticket_number, request_lib)
        if(status): return True

    return False

def push_hook(push_msg):
    """
    Push hook - Check commit messages from pushed refs for ticket numbers
    -> Boolean
    """
    import subprocess, shlex
    from requests import get, ConnectionError

    (base_hash, commit_hash, ref) = push_msg.split(' ')

    blackhole = open('/dev/null', 'w')
    # excludes merge commits
    git_cmd = "git log --no-merges --pretty=oneline %s..%s" %(base_hash, commit_hash)
    git_exec = subprocess.Popen(shlex.split(git_cmd), stdout=subprocess.PIPE, stderr=blackhole)
    git_log = git_exec.stdout.read() 

    commits = git_log.strip().split('\n')
    global git_help
    git_help += str(len(commits))
    for c in commits:
        spc_idx = c.find(' ')
        commit_msg = c[spc_idx:].strip()
        if not check_commit(commit_msg, (get, ConnectionError)):
            return False
    return True

if __name__ == '__main__':
    """ SIDE EFFECTS: Return shell exit code (0 - success | 1 - failure) """
    push_msg = sys.stdin.read()
    if push_hook(push_msg):
        sys.exit(0)
    else:
        sys.exit(1)