Webhook Events to Slack Notifications

This guide shows an end-to-end dataflow that reads an event from a webhook, generates a formatted string, and publishes the result to Slack. While this is a simple example, it has many event notification use cases, such as:

• submission from website forms (via Cloudflare workers or your custom backend).
• activity from e-commerce platforms on purchases and shopping carts.
• notifications from github on your projects’ activities.
• alerts from financial products on your transactions.
• notifications from any product that can invoke a webhook.

This dataflow uses the following features:

• webhook: that creates a public API to receive external events, transform them, and publish them to a topic.
• http-sink: that listens to the same topic and publishes them on Slack.

Show an example of how to build an dataflow that receives webhook events, transforms the input into a readable form, and generates an alert. We assume the events are generated by a user submitting a form, and we’ll format it accordingly.

• Fluvio CLI installed locally
• Account on InfinyOn Cloud

1. Create webhook configuration file
2. Create http-sink configuration file
3. Download SmartModules
4. Start Webhook and Connector
5. Test Dataflow

Create a webhook configuration file called form-webhook.yaml :

meta:
  name: form-webhook
  topic: form-events
webhook:
  outputParts: body
  outputType: json
transforms:
  - uses: infinyon-labs/[email protected]
    with:
      spec:
        match:
          - key: "/type"
            value: "subscribe"
            format:
              with: "📢 {} ({}) subscribed on {}"
              using:
                - "/name"
                - "/email"
                - "/source"
              output: "/formatted"
          - key: "/type"
            value: "use-case"
            format:
              with: "🎊 {} ({}) wants to solve the following '{}' use-case:\n>{}"
              using:
                - "/name"
                - "/email"
                - "/source"
                - "/description"
              output: "/formatted"
        default:
          format:
            with: "{} ({}) submitted a request"
            using:
              - "/name"
              - "/email"
            output: "/formatted"

The webhook reads the JSON body, applies the json-formatter smartmodule to generate readable text, and writes the new record to a topic called form-events. Checkout labs-json-formatter-sm in github for additional information.

Create an HTTP source connector configuration file called slack-form-alerts.yaml :

apiVersion: 0.1.0
meta:
  version: 0.2.5
  name: slack-form-alerts
  type: http-sink
  topic: form-events
  secrets:
    - name: SLACK_USER_ALERTS
http:
  endpoint: "https://hooks.slack.com/services/${{ secrets.SLACK_USER_ALERTS }}"
  headers:
    - "Content-Type: application/json"
transforms:
  - uses: infinyon/[email protected]
    with:
      spec:
        - operation: shift
          spec:
            "formatted": "text"

The sink connector reads from the form-events topic and uses the jolt smartmodule to shift the formatted string into a field called text per the Slack instructions. Checkout fluvio-jolt in github for additional information.

The Slack webhook link is sensitive information, let’s add the access token part to secret in InfinyOn Cloud :

$ fluvio cloud secret set SLACK_USER_ALERTS <webhook-token>

Check out Slack Webhooks on how to create the webhook token.

Download the smartmodules used by the webhook ad the connector:

$ fluvio hub download infinyon/[email protected]
$ fluvio hub download infinyon-labs/[email protected]

Check fluvio smartmodule list to ensure they’ve been downloaded.

Start webhook listener:

$ fluvio cloud webhook create --config form-webhook.yaml

Check fluvio cloud webhook list to ensure it has been successfully provisioned. In checkout the webhook link that we’ll use to test the dataflow: https://infinyon.cloud/webhooks/v1/[token]

Start sink connector:

$ fluvio cloud connector create -c slack-form-alerts.yaml

Check fluvio cloud connector list to ensure it has been successfully provisioned.

Use curl to send a POST request with a fictious user request to our webhook link. In production environments, this iw what a website would send:

$ curl -X POST https://infinyon.cloud/webhooks/v1/<token> \
  -H "Content-Type: application/json" \
  -d '{ "email": "[email protected]", "name": "Alice Liddell", "type": "subscribe", "source": "front-page" }'

The following alert is displayed in Slack:

`📢 Alice Liddell ("[email protected]) subscribed on front-page` will show-up in your slack channel.

That’s all folks!

• Webhook Basics
• Webhook Configuration File
• Cloudflare workers
• JSON formatter SmartModule