Simple Slack slash command that generates jira ticket URLs from a ticket number

jirabot.py

# Copyright (c) 2016 Josh Watson
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
# copies of the Software, and to permit persons to whom the Software is 
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import re
import urlparse

JIRA_URL = 'https://my.jira.project/browse/{}-{}'
DEFAULT_PROJECT = 'MYPROJECT'
TOKEN = 'eajZdcZv4yhm6mCKMemDQKfk'

def jirabot(event, context):
    '''Returns a fully-formed JIRA url for a given ticket number.

    Args:
        event:  A dictionary containing a single key (`formparams`).
            `formparams` is an application/x-www-form-urlencoded string
            representing the fields sent by the outgoing web hook from the
            slack channel. The 'text' key will have the value of the /jira
            command. The command fits the following regex:

            /jira ((?P<project>[a-zA-Z][_a-zA-Z0-9]+)[ -])?(?P<ticket>\d+)

            If `project` isn't specified, the default project will be used. The
            project name is case insensitive, and will be converted to
            uppercase to meet the key requirements of JIRA.

        context: AWS Lambda uses this parameter to provide runtime information
            to the handler. This parameter is of the LambdaContext type. It's
            not actually used by jirabot.

    Returns:
        A dictionary of the form:

        {
            'response_type': 'in_channel',
            'text': <jira_ticket_url_or_error>
        }

    Raises:
        None    
    '''

    # Create a default response. 'text' will be updated after the query
    # is parsed.
    jira_response = {
        'response_type': 'in_channel',
        'text': "I couldn't parse your request."
    }

    # turn the parameters sent from slack into a dictionary
    try:
        form_params = urlparse.parse_qs(event.get('formparams'))
    except:
        return jira_response

    if form_params is None:
        return jira_response

    # return empty if the token doesn't match
    try:
        token = form_params.get('token')[0]
    except TypeError:
        token = ''

    if token != TOKEN:
        return {'text': 'Invalid token.'}

    # get the ticket request
    try:
        ticket_request = form_params.get('text')[0]
    except TypeError:
        ticket_request = None

    if ticket_request is None:
        return jira_response

    ticket_match = re.match(
        r'((?P<project>[a-zA-Z][_a-zA-Z0-9]+)[ -])?(?P<ticket>\d+)',
        ticket_request
    )

    if ticket_match is None:
        return jira_response

    # extract the project and ticket number from the query
    project = ticket_match.group('project')
    if project is None:
        project = DEFAULT_PROJECT

    ticket = ticket_match.group('ticket')

    # format the URL response
    jira_response['text'] = JIRA_URL.format(project.upper(), ticket)

    return jira_response