Using FunctionGraph to Forward SMN Messages to Slack

Scenarios

This section described how to use FunctionGraph to forward SMN messages to Slack. Slack, developed by Slack Technologies, is cloud-based instant messaging software. Slack does not have an API to receive HTTPS messages sent from SMN. So, you cannot directly add a Slack subscription to receive SMN notifications. Instead, you need to use FunctionGraph to forward messages to a specified URL.

Prerequisites

• You have created an SMN message topic, for example, smn-test. For details, see Creating a Topic.
• You have downloaded Slack.

Procedure

To use FunctionGraph to send SMN messages to Slack, perform the following operations:

1. Configuring Slack
2. Configuring FunctionGraph
3. Configuring SMN

Configuring Slack

The following operations are for reference only. For details, visit the Slack website.

1. Create or select a channel on Slack.
   Figure 1 Creating a channel
   
2. Choose Apps > Manage > Browse apps.
   Figure 2 Choosing Apps
   
3. Search for Incoming Webhooks and click Add.
   Figure 3 Adding Incoming Webhooks
   
4. Click Configuration to go to the configuration page and obtain the Webhook URL.
   Figure 4 Clicking Configuration
   
   Figure 5 Obtaining the Webhook URL
   
5. Save the obtained Webhook URL.
   Figure 6 Saving the Webhook URL
   

Configuring FunctionGraph

1. Log in to the FunctionGraph console. In the navigation pane, choose Functions > Function List.
2. Click Create Function in the upper right corner and choose Select template.
3. Select the template shown in Figure 7 and click Configure.
   Figure 7 Selecting a template
   
4. Set the function name, select an agency, retain default values for other parameters, and click Create Function.
   Figure 8 Configuring basic information
   
5. On the configuration details page, click the Code tab and edit the code in index.py.
   Figure 9 Editing the code
   

   The following is an example of the code sent to Slack: (In actual use, set webhook_url to the Webhook URL obtained from Slack or perform other operations as required.)

   # -*- coding:utf-8 -*-
   import json
   import requests
   
   def handler (event, context):
       # Common part: Construct the body fields required by the destination address. event contains all fields sent by SMN.
       payload = {'text': event["record"][0]["smn"]["message"]}
   
       # Forwarding part: Call a Slack API to forward messages to the Slack platform.
       try:
           webhook_url = 'Webhook URL obtained from Slack'
           response = requests.post(webhook_url, json=payload)
           response.raise_for_status()
           print('Message sent successfully')
       except requests.exceptions.RequestException as e:
           print(f"Error sending message to Slack: {e}")
   
       return event

6. After the editing is complete, press Ctrl+S to save the modification and update the code.
7. Click Create Trigger.
8. Set the following parameters:
   • Trigger Type: Select Simple Message Notification (SMN).
   • Topic Name: Select a topic, for example, smn-test.
   Figure 10 Creating a trigger
   
9. Click OK. After the topic is created, all messages sent to the topic are forwarded to the destination address through FunctionGraph.

Configuring SMN

1. Log in to the SMN console. In the navigation pane, choose Topic Management > Topics.
2. Locate the topic smn-test and click Add Subscription in the Operation column.
3. Set the following parameters:
   • Protocol: Select FunctionGraph (function).
   • Endpoint: Select a created function, for example, smn-test.
   Figure 11 Adding a subscription
   
4. Click OK.
5. Locate the topic smn-test and click Publish Message in the Operation column.
6. Set the following parameters:
   • Message Format: Text
   • Message Content: Enter the message content.
7. Click OK.

Viewing the Received Message

After a message is published, you can receive the message on Slack. Figure 12 shows an example.

Figure 12 Message received on Slack