359-sample-error-workflow

This n8n workflow demonstrates a robust error handling mechanism, automatically notifying relevant parties via SMS and Mattermost when a main workflow execution fails. It ensures that critical failures are immediately escalated, allowing for prompt investigation and resolution.

What it does

This workflow acts as an error handler for other n8n workflows. When another workflow on your n8n instance encounters an error and fails, this workflow will be triggered to perform the following steps:

1. Listens for Errors: It is triggered by the failure of any other n8n workflow execution.
2. Sends SMS Notification: Upon receiving an error, it immediately sends an SMS message via Twilio to a predefined recipient, alerting them of the workflow failure.
3. Posts Mattermost Message: Concurrently, it posts a detailed error message to a specified Mattermost channel, providing more context about the failure for team awareness and collaborative debugging.

Prerequisites/Requirements

To use this workflow, you will need:

• n8n Instance: An active n8n instance where this workflow can be imported and run.
• Twilio Account: A Twilio account with an active phone number capable of sending SMS messages.
• Mattermost Account: A Mattermost instance and a channel where error notifications should be posted.
• Twilio Credentials: Configured Twilio credentials in n8n (Account SID, Auth Token, and a "From" phone number).
• Mattermost Credentials: Configured Mattermost credentials in n8n (Mattermost URL and an Access Token or Webhook URL).

Setup/Usage

1. Import the Workflow:
   • Download the provided JSON file for this workflow.
   • In your n8n instance, go to "Workflows" and click "New".
   • Click the "Import from JSON" button and paste the workflow JSON or upload the file.
2. Configure Credentials:
   • Twilio Node (ID: 45):
     • Click on the "Twilio" node.
     • Select or create a new Twilio credential. You will need your Twilio Account SID and Auth Token.
     • In the "To" field, enter the phone number to which error alerts should be sent (e.g., +1234567890).
     • In the "From" field, select your Twilio phone number.
     • Customize the "Body" of the SMS message as needed. You can use expressions to include details from the error trigger (e.g., Workflow '{{ $json.workflow.name }}' failed with error: {{ $json.error.message }}).
   • Mattermost Node (ID: 55):
     • Click on the "Mattermost" node.
     • Select or create a new Mattermost credential. You will need your Mattermost URL and an Access Token or Webhook URL.
     • In the "Channel" field, specify the Mattermost channel where the error message should be posted (e.g., error-alerts).
     • Customize the "Message" field to include relevant error information.
3. Activate the Workflow:
   • Once credentials are configured, click the "Activate" toggle in the top right corner of the workflow editor to set the workflow to "Active" status.
4. Configure Error Workflow in other Workflows:
   • For any workflow you want to monitor with this error handler, go to its "Workflow Settings".
   • Under the "Error Workflow" section, select this workflow ("359-sample-error-workflow") from the dropdown list.
   • Now, if that workflow fails, it will trigger this error handling workflow.