Aim:

Methods to send the post messages to slack channels.

Solution:

There are two ways to post a message directly from any system to the Slack channel

1. Incoming Webhooks
1. Slack App

1. Incoming Webhooks:

It is an integration plugin that we can add manually to any group channel. Adding it creates a unique HTTPS URL.

EXAMPLE CODE

import json
import requests


def send_slack_message(payload, webhook):
    """Send a Slack message to a channel via a webhook.

    Args:
        payload (dict): Dictionary containing Slack message, i.e. {"text": "This is a test"}
        webhook (str): Full Slack webhook URL for your chosen channel.

    Returns:
        HTTP response code, i.e. <Response [503]>
    """

    return requests.post(webhook, json.dumps(payload))


webhook = 'https://hooks.slack.com/services/T2HSR4Y3D/B04FR9ADC4V/Lqg9CHyR0EddV3U' # MODIFY WITH YOUR URL

payload = {"text": "Anomaly detected!"}
send_slack_message(payload, webhook)

2. Slack App

Slack provides an SDK to develop an app that can control and simulates the workflow in slack. Sending messages to multiple channels, auto-response, and managing the scopes for permissions many features available in it. Slack recommends the Slack App creation, as the incoming webhooks feature will be deprecated in the future.

URL - https://api.slack.com/apps?new_app=1

Sample Code - https://api.slack.com/messaging/sending

import logging
import os
# Import WebClient from Python SDK (github.com/slackapi/python-slack-sdk)
from slack_sdk import WebClient
from slack_sdk.errors import SlackApiError

# WebClient instantiates a client that can call API methods
# When using Bolt, you can use either `app.client` or the `client` passed to listeners.
client = WebClient(token=os.environ.get("SLACK_BOT_TOKEN"))
logger = logging.getLogger(__name__)
# TS of message you want to post thread to
message_ts = "1610144875.000600"

# ID of channel you want to post message to
channel_id = "C01JASD6802"

try:
    # Call the chat.postMessage method using the WebClient
    # The client passes the token you included in initialization    
    result = client.chat_postMessage(
        channel=channel_id,
        thread_ts=message_ts,
        text="Hello again :wave:"
        # You could also use a blocks[] array to send richer content
    )

    print(result)

except SlackApiError as e:
    print(f"Error: {e}")

Kafka Bot Message Template

Standanlone script to send messages to slack channel (incoming webhook) using python (requests)

import json
import sys
import random
import requests

"""
Reference -
https://api.slack.com/reference/messaging/attachments

Examples - 
https://app.slack.com/block-kit-builder/T02GEFU92#%7B%22blocks%22:%5B%7B%22type%22:%22section%22,%22text%22:%7B%22type%22:%22mrkdwn%22,%22text%22:%22%E2%80%A2%20Detective%20Chimp%5Cn%E2%80%A2%20Bouncing%20Boy%5Cn%E2%80%A2%20Aqualad%22%7D%7D,%7B%22type%22:%22image%22,%22title%22:%7B%22type%22:%22plain_text%22,%22text%22:%22I%20Need%20a%20Marg%22,%22emoji%22:true%7D,%22image_url%22:%22https://assets3.thrillist.com/v1/image/1682388/size/tl-horizontal_main.jpg%22,%22alt_text%22:%22marg%22%7D,%7B%22type%22:%22context%22,%22elements%22:%5B%7B%22type%22:%22image%22,%22image_url%22:%22https://pbs.twimg.com/profile_images/625633822235693056/lNGUneLX_400x400.jpg%22,%22alt_text%22:%22cute%20cat%22%7D,%7B%22type%22:%22mrkdwn%22,%22text%22:%22*Cat*%20has%20approved%20this%20message.%22%7D%5D%7D,%7B%22type%22:%22header%22,%22text%22:%7B%22type%22:%22plain_text%22,%22text%22:%22This%20is%20a%20header%20block%22,%22emoji%22:true%7D%7D,%7B%22type%22:%22divider%22%7D,%7B%22type%22:%22section%22,%22text%22:%7B%22type%22:%22mrkdwn%22,%22text%22:%22This%20is%20a%20mrkdwn%20section%20block%20:ghost:%20*this%20is%20bold*,%20and%20~this%20is%20crossed%20out~,%20and%20%3Chttps://google.com%7Cthis%20is%20a%20link%3E%22%7D%7D%5D%7D
https://app.slack.com/block-kit-builder/T02GEFU92#%7B%22blocks%22:%5B%7B%22type%22:%22header%22,%22text%22:%7B%22type%22:%22plain_text%22,%22text%22:%22New%20request%22,%22emoji%22:true%7D%7D,%7B%22type%22:%22section%22,%22fields%22:%5B%7B%22type%22:%22mrkdwn%22,%22text%22:%22*Type:*%5CnPaid%20Time%20Off%22%7D,%7B%22type%22:%22mrkdwn%22,%22text%22:%22*Created%20by:*%5Cn%3Cexample.com%7CFred%20Enriquez%3E%22%7D%5D%7D,%7B%22type%22:%22section%22,%22fields%22:%5B%7B%22type%22:%22mrkdwn%22,%22text%22:%22*When:*%5CnAug%2010%20-%20Aug%2013%22%7D,%7B%22type%22:%22mrkdwn%22,%22text%22:%22*Type:*%5CnPaid%20time%20off%22%7D%5D%7D,%7B%22type%22:%22section%22,%22fields%22:%5B%7B%22type%22:%22mrkdwn%22,%22text%22:%22*Hours:*%5Cn16.0%20(2%20days)%22%7D,%7B%22type%22:%22mrkdwn%22,%22text%22:%22*Remaining%20balance:*%5Cn32.0%20hours%20(4%20days)%22%7D%5D%7D,%7B%22type%22:%22section%22,%22text%22:%7B%22type%22:%22mrkdwn%22,%22text%22:%22%3Chttps://example.com%7CView%20request%3E%22%7D%7D%5D%7D
"""
#  PASTE YOUR  SLACK CHANNEL WEBHOOK URL HERE
url = 'https://hooks.slack.com/services/XXXXX/XXXXX/XXXXX'
#  TYPE YOUR  SLACK CHANNEL NAME HERE
channel_name = "#dev-rd"

emoji_data = '''
:sunny:
:umbrella:
:cyclone:
:snowflake:
:zap:
:snowman:
:snake:
:earth_asia:
:computer:
:loudspeaker:
:hourglass:
:loop:
:satellite:
:mag:
:high_brightness:
:bomb:
:simple_smile:
:traffic_light:
:beginner:
:circus_tent:
:performing_arts:
'''
name_data = '''
botload
adminbot
incredibot
votebot
okokbot
humanbot
slavebot
botamota
bagbot
blitzbot
fabbot
fatbot
botrover
fancybot
helpingbot
goodbot
botsauce
batbot
babybot
unseenbot
remotebot
zoombot
superbot
coolbot
wackybot
wickedbot
modernbot
savagebot
blasterbot
primebot
spiderbot'''

name_data = name_data.split("\n")
emoji_data = emoji_data.split("\n")
# Getting random bot name
bot_name = random.choice(name_data)
# Getting random slack emoji
emoji_id = random.choice(emoji_data)
# Generating random hex color code
hex_number = '#' + str(hex(random.randint(1118481, 16777215)))[2:]

sample_attachment1 = [
    {
        "fallback": "New open task [Urgent]:<https://www.vijayanandrp.com/|Vijay Profile>",
        "pretext": "New open task [Urgent]:<https://www.vijayanandrp.com/|Vijay Profile>",
        # "color": "#D00000",
        "color": hex_number,
        "unfurl_links": True,
        "fields": [
            {
                "title": """A Sample Message from Python. This is much easier than I thought it would be. <http://www.youtube.com/watch?v=wq1R93UMqlk| Youtube>""",
                "value": f"New Incoming Message {emoji_id}",
                "short": False,
            }
        ]
    }
]

sample_attachment = [
    {
        "mrkdwn_in": ["text"],
        "color": "#36a64f",
        "pretext": "Optional pre-text that appears above the attachment block",
        "author_name": "Vijay_Anand",
        "author_link": "http://flickr.com/bobby/",
        "author_icon": "https://placeimg.com/16/16/people",
        "title": "title",
        "title_link": "https://api.slack.com/",
        "text": "Optional `text` that appears within the attachment",
        "fields": [
            {
                "title": "A field's title",
                "value": "This field's value",
                "short": False
            },
            {
                "title": "A short field's title",
                "value": "A short field's value",
                "short": True
            },
            {
                "title": "A second short field's title",
                "value": "A second short field's value",
                "short": True
            }
        ],
        "thumb_url": "http://placekitten.com/g/200/200",
        "footer": "footer",
        "footer_icon": "https://platform.slack-edge.com/img/default_application_icon.png",
        "ts": 123456789
    }
]

sample_attachment2 = [{
    "blocks": [
        {
            "type": "header",
            "text": {
                "type": "plain_text",
                "text": "New request",
                "emoji": True
            }
        },
        {
            "type": "section",
            "fields": [
                {
                    "type": "mrkdwn",
                    "text": "*Type:*\nPaid Time Off"
                },
                {
                    "type": "mrkdwn",
                    "text": "*Created by:*\n<example.com|Fred Enriquez>"
                }
            ]
        },
        {
            "type": "section",
            "fields": [
                {
                    "type": "mrkdwn",
                    "text": "*When:*\nAug 10 - Aug 13"
                },
                {
                    "type": "mrkdwn",
                    "text": "*Type:*\nPaid time off"
                }
            ]
        },
        {
            "type": "section",
            "fields": [
                {
                    "type": "mrkdwn",
                    "text": "*Hours:*\n16.0 (2 days)"
                },
                {
                    "type": "mrkdwn",
                    "text": "*Remaining balance:*\n32.0 hours (4 days)"
                }
            ]
        },
        {
            "type": "section",
            "text": {
                "type": "mrkdwn",
                "text": "<https://example.com|View request>"
            }
        }
    ]
}]

if __name__ == '__main__':
    for attachment in [sample_attachment1, sample_attachment, sample_attachment2]:
        bot_name = random.choice(name_data)
        emoji_id = random.choice(emoji_data)
        hex_number = '#' + str(hex(random.randint(1118481, 16777215)))[2:]
        print(bot_name, emoji_id, hex_number)
        slack_data = {
            "username": bot_name,
            "icon_emoji": emoji_id,
            "channel": channel_name,

            "attachments": attachment
        }
        byte_length = str(sys.getsizeof(slack_data))
        headers = {'Content-Type': "application/json", 'Content-Length': byte_length}
        response = requests.post(url, data=json.dumps(slack_data), headers=headers)
        print(response)

        if response.status_code != 200:
            raise Exception(response.status_code, response.text)

#mythoughts