Simple example script to send a message to Slack in Python

post_to_slack.py

'''Simple example script below is quite straightforward. 

Although Slack recommends integrating to it by writing Apps[1], 
the old-school webhook integration still works as well

[1] https://api.slack.com/start/overview
'''

import json
import os
import sys

from requests import codes, post
from robot.api import ExecutionResult

# Get the Slack webhook url (https://api.slack.com/messaging/webhooks) from environment variable so we do not expose it needlessly 
URL = os.environ.get('SLACK_URL', None)
if URL is None:
    raise Exception('$SLACK_URL env var not defined D:')

# message template used for the message
TEXT = '''MOI

Updating the following dependencies have resulted in {test_status}:

{deps}
'''

def post_to_slack(message):
    r = post(URL, data=json.dumps({'text': message}))
    if r.status_code != codes.ok: # only output something if there's a failure
        print(r.json())
    r.raise_for_status() # in case of erroneous response, throw an exception


def main(robot_output, new_requirements, original_requirements):
    # parse test execution status from output.xml using Robot Framework’s API (https://robot-framework.readthedocs.io/en/stable/)
    robot_result = ExecutionResult(robot_output)
    test_run_passed = bool(robot_result.statistics.total.failed == 0)

    # read in both requirement files: the old, known dependencies and the ones used in the test execution
    with open(new_requirements, 'r') as f:
        new_requirements = f.readlines()
    # separate dependency name and version to make comparing dependencies easier
    new_requirements = [line.split('==') for line in new_requirements]  
    
    with open(original_requirements, 'r') as f:
        old_requirements = f.readlines()
    old_requirements = sorted(line.split('==') for line in old_requirements)

    # new_requirements now has more dependencies than old_requirements
    # only retain original *main level* dependecies
    # others are sub-dependencies we do not want
    new_requirements = sorted(filter(lambda req: req[0] in [r[0] for r in old_requirements],
                                     new_requirements))

    # format the message to be posted to Slack
    msg = TEXT.format(test_status='PASS' if test_run_passed else 'FAIL',
                      deps='\n'.join(f'{"==".join(dep[0])} => {"==".join(dep[1])}'
                                     for dep in zip(old_requirements,
                                                    new_requirements)))
    post_to_slack(msg)

if __name__ == '__main__':
    main(*sys.argv[1:])