Python wrapper script for Slack chat.postMessage API

slackpost.py

#!/usr/bin/python
import sys
import argparse
import requests


parser = argparse.ArgumentParser(description = 'Slack chat.postMessage wrapper')
parser.add_argument('token', help = 'The OAuth token for your app with chat:write:bot permission.')
parser.add_argument('channel', help = 'The channel name to post to, without the pound sign.')
parser.add_argument('-m', '--message', help = 'The message to send. Either this or the file parameter is required.')
parser.add_argument('-f', '--file', help = 'The message text file to send. Either this or the message parameter is required.')
parser.add_argument('-a', '--attachment', nargs = '*', help = 'An optional attachment text file to send. Alternatively you can pipe the attachment to STDIN.')
parser.add_argument('-ac', '--attachment-color', help = 'The color used for the attachment\'s indentation.')

args = parser.parse_args()


payload = {
        'channel': args.channel
}


# Compose text (simply append if both the message and file are supplied)
if args.message is not None:
        text = args.message.replace('\\n', '\n')
else:
        text = ''

if args.file is not None:
        try:
                with open(args.file, 'r') as messageFile:
                        text += messageFile.read()
        except:
                print('Error while trying to read message from ' + args.file)
                #exit()

payload['text'] = text
# Parse attachment(s)
def add_attachment(text, filename = None):
        attachment = {
                'text': text
        }

        if args.attachment_color is not None:
                attachment['color'] = args.attachment_color

        if filename is not None:
                attachment['title'] = filename

        if 'attachments' in payload:
                payload['attachments'].append(attachment)
        else:
                payload['attachments'] = [attachment]


# isatty returns false if the input is not a terminal, e.g. piped in data
if not sys.stdin.isatty():
        add_attachment(sys.stdin.read())


if args.attachment is not None:
        for attachment in args.attachment:
                try:
                        with open(attachment, 'r') as attachmentFile:
                                add_attachment(attachmentFile.read(), attachment)
                except:
                        print('Error while trying to read attachment from ' + attachment)
                        #exit()


headers = {
        'Content-Type': 'application/json; charset=UTF-8',
        'Authorization': 'Bearer ' + args.token
}

response = requests.post('https://slack.com/api/chat.postMessage', headers = headers, json = payload)
if response.status_code != 200:
        print(response.text)