Notifications

When a workflow completes, users can be notified by email, Pagerduty, or Slack.

The content of these notifications is configurable at the platform level.

Usage

When a workflow reaches a specified terminal workflow execution phase the flytekit:flytekit.Email, flytekit:flytekit.PagerDuty, or flytekit:flytekit.Slack objects can be used in the construction of a flytekit:flytekit.LaunchPlan.

Example


    from flytekit import Email, LaunchPlan
    from flytekit.models.core.execution import WorkflowExecutionPhase

    # This launch plan triggers email notifications when the workflow execution it triggered reaches the phase `SUCCEEDED`.
    my_notifiying_lp = LaunchPlan.create(
        "my_notifiying_lp",
        my_workflow_definition,
        default_inputs={"a": 4},
        notifications=[
            Email(
                phases=[WorkflowExecutionPhase.SUCCEEDED],
                recipients_email=["[email protected]"],
            )
        ],
    )

Notifications can be combined with schedules to automatically alert you when a scheduled job succeeds or fails.

Setting Up Workflow Notifications

The notifications top-level portion of the FlyteAdmin config specifies how to handle notifications.

As with schedules, the notifications handling is composed of two parts. One handles enqueuing notifications asynchronously and the second part handles processing pending notifications and actually firing off emails and alerts.

This is only supported for Flyte instances running on AWS or GCP.

AWS Config

To publish notifications, you’ll need to set up an SNS topic.

In order to process notifications, you’ll need to set up an AWS SQS queue to consume notification events. This queue must be configured as a subscription to your SNS topic you created above.

In order to actually publish notifications, you’ll need a verified SES email address which will be used to send notification emails and alerts using email APIs.

The role you use to run FlyteAdmin must have permissions to read and write to your SNS topic and SQS queue.

Let’s look at the following config section and explain what each value represents:


  notifications:
    # By default, the no-op executor is used.
    type: "aws"

    # This specifies which region AWS clients will use when creating SNS and SQS clients.
    region: "us-east-1"

    # This handles pushing notification events to your SNS topic.
    publisher:

      # This is the arn of your SNS topic.
      topicName: "arn:aws:sns:us-east-1:{{ YOUR ACCOUNT ID }}:{{ YOUR TOPIC }}"

    # This handles the recording notification events and enqueueing them to be
    # processed asynchronously.
    processor:

      # This is the name of the SQS queue which will capture pending notification events.
      queueName: "{{ YOUR QUEUE NAME }}"

      # Your AWS `account id, see: https://docs.aws.amazon.com/IAM/latest/UserGuide/console_account-alias.html#FindingYourAWSId
      accountId: "{{ YOUR ACCOUNT ID }}"

    # This section encloses config details for sending and formatting emails
    # used as notifications.
    emailer:

      # Configurable subject line used in notification emails.
      subject: "Notice: Execution \"{{ workflow.name }}\" has {{ phase }} in \"{{ domain }}\"."

      # Your verified SES email sender.
      sender:  "[email protected]"

      # Configurable email body used in notifications.
      body: >
        Execution \"{{ workflow.name }} [{{ name }}]\" has {{ phase }} in \"{{ domain }}\". View details at
        <a href=\http://flyte.company.com/console/projects/{{ project }}/domains/{{ domain }}/executions/{{ name }}>
        http://flyte.company.com/console/projects/{{ project }}/domains/{{ domain }}/executions/{{ name }}</a>. {{ error }}

The full set of parameters which can be used for email templating are checked into code.

Example config

You can find the full configuration file here.

GCP Config

You’ll need to set up a Pub/Sub topic to publish notifications to, and a Pub/Sub subscriber to consume from that topic and process notifications. The GCP service account used by FlyteAdmin must also have Pub/Sub publish and subscribe permissions.

Email service

In order to actually publish notifications, you’ll need an account with an external email service which will be used to send notification emails and alerts using email APIs.

Currently, SendGrid is the only supported external email service, and you will need to have a verified SendGrid sender. Create a SendGrid API key with Mail Send permissions and save it to a file key.

Create a K8s secret in FlyteAdmin’s cluster with that file:

kubectl create secret generic -n flyte --from-file key sendgrid-key

Mount the secret by adding the following to the flyte-core values YAML:

        
    
    flyteadmin:
      additionalVolumes:
      - name: sendgrid-key
        secret:
          secretName: sendgrid-key
          items:
            - key: key
              path: key
      additionalVolumeMounts:
      - name: sendgrid-key
        mountPath: /sendgrid

Helm configuration

In the flyte-core values YAML, the top-level notifications config should be placed under workflow_notifications.

        
    

    workflow_notifications:
      enabled: true
      config:
        notifications:
          type: gcp
          gcp:
            projectId: "{{ YOUR PROJECT ID }}"
          publisher:
            topicName: "{{ YOUR PUB/SUB TOPIC NAME }}"
          processor:
            queueName: "{{ YOUR PUB/SUB SUBSCRIBER NAME }}"
          emailer:
            emailServerConfig:
              serviceName: sendgrid
              apiKeyFilePath: /sendgrid/key
            subject: "Flyte execution \"{{ name }}\" has {{ phase }} in \"{{ project }}\"."
            sender: "{{ YOUR SENDGRID SENDER EMAIL }}"
            body: View details at <a href=https://{{ YOUR FLYTE HOST }}/console/projects/{{ project }}/domains/{{ domain }}/executions/{{ name }}>https://{{ YOUR FLYTE HOST }}/console/projects/{{ project }}/domains/{{ domain }}/executions/{{ name }}</a>

Webhook connector

In recent flytekit versions (>=1.15.0) it’s possible to setup a WebhookTask object to send notifications to any system through webhooks. The following example uses Slack without email or queue configurations:

        
    

notification_task = WebhookTask(
   name="failure-notification",
   url="https://hooks.slack.com/services/xyz", #your Slack webhook
   method=http.HTTPMethod.POST,
   headers={"Content-Type": "application/json"},
   data={"text": "Workflow failed: {inputs.error_message}"},
   dynamic_inputs={"error_message": str},
   show_data=True,
   show_url=True,
   description="Send notification on workflow failure"
)
...

@fl.workflow
def ml_workflow_with_failure_handling() -> float:
   try:
       X, y = load_and_preprocess_data()
       model = train_model(X=X, y=y)
       accuracy = evaluate_model(model=model, X=X, y=y)
       return accuracy
   except Exception as e:
       # Trigger the notification task on failure
       notification_task(error_message=str(e))
       raise  