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Receive Alert Notifications via Slack

Setup Slack integration and receive alert notifications from Last9.

Getting started

Last9 can send alert notifications and resolutions to Slack channels. This document provides step-by-step instructions on how to set up Slack integration with Last9 and start receiving alert notifications.

Setting up an Incoming Webhook in Slack

  1. Navigate to Slack API Apps and click Create New App

  2. Select From scratch and provide:

    • App Name: A descriptive name (e.g., “Last9 Alerts”)
    • Workspace: Select the workspace where you want to receive alerts

  3. Click Create App

  4. In your app settings, navigate to Incoming Webhooks in the left sidebar

  5. Toggle Activate Incoming Webhooks to On

  6. Click Add New Webhook to Workspace

  7. Select the channel where you want alert notifications to be posted and click Allow

  8. Copy the generated webhook URL. It will look like:

    https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX

Setting up a notification channel in Last9

  1. In Notification Channels, click Add to create a new channel

    Notification channels list

  2. Provide the following details:

    • Channel Name: A descriptive name to easily identify the channel (e.g., “Slack Production Alerts”)
    • Channel: Select Slack from the dropdown
    • Webhook URL: Paste the Slack webhook URL copied from the previous step
    • Send Resolved: Enable this option if you want to be notified when an alert has been resolved

    Add Slack channel

  3. Click Test Config to send a test message to your Slack channel and verify the integration is working

    Test Slack configuration

  4. Click Save to enable the channel

Assigning a notification channel to an alert group

  1. Navigate to your Alert Group in Alert Studio

  2. Click on the notification channel icon to configure notifications

  3. Select your Slack channel from the dropdown

Slack Notification Format

Last9 sends rich notifications to Slack that include:

FieldDescription
Event TypeTRIGGER or RESOLVED indicator
SummaryAlert title and description
SeverityBREACH (critical) or THREAT (warning)
ComponentThe affected component or service
ClassType of alert (e.g., Static Threshold, SLO Breach)
TimestampWhen the alert was triggered
Custom DetailsAdditional context like service, environment, error rates
Dashboard LinkDirect link to view the alert in Last9

Using Terraform

You can also create the Slack notification channel using the Last9 Terraform Provider:

resource "last9_notification_channel" "slack" {
  name          = "slack-production-alerts"
  type          = "slack"
  destination   = "https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX"
  send_resolved = true
}

Troubleshooting

Notifications not appearing in Slack

  1. Verify the webhook URL is correct and starts with https://hooks.slack.com/services/
  2. Check that the Slack app is still installed in your workspace
  3. Ensure the channel selected for the webhook still exists
  4. Verify the app has permission to post to the channel

Test message not working

  1. Click Test Config to send a test message
  2. Check if the test message appears in your Slack channel
  3. If it doesn’t appear, verify the webhook URL is correct

Rate limiting

Slack has rate limits for incoming webhooks. If you’re sending a high volume of alerts, some messages may be delayed. Consider consolidating alerts using alert grouping in Last9.

Webhook URL expired or revoked

If your webhook stops working:

  1. Navigate to your Slack app settings
  2. Go to Incoming Webhooks
  3. Check if the webhook is still active
  4. If needed, create a new webhook and update the URL in Last9

Please get in touch with us on Discord or Email if you have any questions.