Slack

Generate slack incoming webhook URL

To post a slack notification, that you need to generate an incoming webhook URL. To generate the URL, follow these steps: Incoming webhooks for Slack.

Configuring a slack destination

Before you configure Slack as a destination for Direct Messages, ensure you have created and configured a Slack app with a bot token scope of chat:write. Refer to the Slack API documentation for more information: (https://api.slack.com/quickstart#creating).

To configure a Slack destination, follow these steps:

1. Log in to your Event Notifications instance dashboard and navigate to Destinations.

2. Click Add to add a new destination.

3. In the Add a destination side panel, provide the following details:

   • Name: Enter a name for your destination.
   • Description: Optionally, enter a description for your destination.
   • Type: Under Destination, select Slack from the list as your destination type.
   • Send messages: Choose one of the following options:
     • Using incoming webhooks: Provide the Slack Incoming Webhook URL.
     • Using direct messages: Provide the Bot User OAuth Token.

Configuring a slack subscription

1. Using Incoming Webhooks
   • You can add attachment color to individual Slack subscriptions based on a hex code. For example, use #0000FF to set the color to blue.
2. Using Direct Messages
   • You can provide a list of member ids and channel ids. If channel ids are provide then the application shall be integrated into the specified channels.

How a default slack notification (without template) from Event Notifications looks

Event notification generates slack notifications from incoming payload. The template event notification use to send to slack looks like following -

{
   "text": "*{{event.ibmendefaultshort}}*",
   "attachments": [{
      "color": "{{config.subscription.attachment_color}}",
      "blocks": [{
         "type": "section",
         "text": {
            "type": "mrkdwn",
            "text": "{{event.ibmendefaultlong}}"
         }
      },
      {
         "type": "divider"
      },
      {
         "type": "section",
         "text": {
            "type": "mrkdwn",
            "text": "```{{event.data}} ```"
         }
      }
      ]
   }]
}

Here -

ibmendefaultshort is the default short payload that is provided in the incoming payload. attachment_color is the color that is applied to the notification, which was provided during subscription. ibmendefaultlong is the default long payload that is provided in the incoming payload. data is the data JSON provided in the incoming payload and format as JSON in the slack notification.

Testing a Slack destination configuration

You can test a Slack destination in the options menu provided againts the destination. You can effortlessly test a destination, whether the provided configuration is correct or not with a single click.

For more information on testing a destination, see here.

Handlebars Integration

Handlebars is a templating language that allows for dynamic content generation within templates. In the context of IBM Event Notification Slack Destination, Handlebars can be used to customize notification messages using template variables and conditional logic.

{{variable_name}}

Event Name: {{event_name}}

{{#if condition}}
   
{{else}}
   
{{/if}}

{{#if severity}}
   Severity: {{severity}}
{{else}}
   No severity information available
{{/if}}

{{#ifEqual status 'active'}}
    <span>User is active</span>
{{else}}
    <span>User is inactive</span>
{{/ifEqual}}

Input API for Templates

The Input API for Templates provides a mechanism for users to define notification message templates programmatically. Users can generate JSON blocks representing Block Kit layouts using the Block Kit Builder and encode them in base64 format to include in their templates.

{
   "blocks": [
      {
         "type": "section",
         "text": {
            "type": "mrkdwn",
            "text": "This is a notification message."
         }
      },
      {
         "type": "divider"
      },
      {
         "type": "actions",
         "elements": [
            {
               "type": "button",
               "text": {
                  "type": "plain_text",
                  "text": "View Details",
                  "emoji": true
               },
               "url": "https://example.com/details"
            }
         ]
      }
   ]
}

{
	"name": "Template for",
	"params": {
		"body": "eyJibG9ja3MiOlt7InR5cGUiOiJzZWN0aW9uIiwidGV4dCI6eyJ0eXBlIjoibXJrZG93biIsInRleHQiOiJUaGlzIGlzIGEgbm90aWZ5aW5nIG1lc3NhZ2UuIn19LHsidHlwZSI6ImRpdmlkZXIiLCJ0ZXh0Ijp7InR5cGUiOiJtbmF2IiwidGV4dCI6IlRoaXMgaXMgYSBuZXcgbm90aWZ5aW5nIG1lc3NhZ2UuIiwiZW1vamkiOnRydWV9fV0seyJ0eXBlIjoiYWN0aW9ucyIsImVsZW1lbnRzIjpbeyJ0eXBlIjoicGxhaW5fdGV4dCIsInRleHQiOnsic2VsZWN0aW9yIjp7InR5cGUiOiJwbGFpbl90ZXh0IiwidGV4dCI6IlZpZXcgRGV0YWlscyIsImVtb2ppIjp0cnVlfX19XX0="
	},
	"type": "slack.notification"
}

Slack retry policy

When publishing a slack notification, issues such as network errors and application glitches can cause the requests to fail. A retry is used to provide resiliency to external requests. Attempt to retry the requests in such situations by using the following values:

• Limit = 60 seconds: total time that the service retries.
• Step = 5 seconds: after each failure, the service waits 5 seconds before retrying. This delay prevents bombarding of the external services (webhook).

In addition, the following timeout conditions cause the slack call to fail:

• A connection timeout of 10 seconds
• A response timeout of 60 seconds

If a call to the Slack webhook URL fails even after retry attempts, the notification is lost.