Enabling event notifications for Code Engine

Setting up a trigger in the console

In this example, you use the IBM Cloud console to set up a timer trigger in Event Notifications that calls a Code Engine job every 6 hours.

Before you begin, make sure you have the following in your account.

• An Event Notifications instance
• A Code Engine project.
• A target job within the project.

Complete the following steps to create the trigger.

1. Set up a source in your Event Notifications instance.

   1. Set Up a Source
   2. Choose Periodic Timer as the event source.
   3. Set Up a Topic A Topic acts as a filter for events. You’ll use this to define the events of interest.
   4. Give your topic a name. For example, "Periodic-Trigger-6hr".
   5. Set the cron expression (0 */6 * * *) so that the topic emits events every 6 hours. Learn more about creating-a-topic-with-periodic-timer.

2. Set up a destination. The destination is where the event is sent for processing. In this example, choose your existing Code Engine job from the list of available destinations. The job will act as the endpoint that will be triggered when the event occurs.

   Note: A service-to-service authorization is needed between Event Notifications and Code Engine. This can be configured by going to Manage > Access > Authorizations in the console. However, when you use the console, this part is handled automatically.

3. Create a Subscription that links the Topic and the Destination.

   1. Select the "Periodic-Trigger-6hr" topic that you created earlier.

   2. Choose your Code Engine job as the destination.

The subscription ensures that when the event is emitted every 6 hours, the Code Engine job will be triggered. You can observe and verify the interval by reviewing the the Jobruns tab of your project.

The previous steps configured a job as the destination. However, this same procedure can be used if your destination an app. When setting up the destination, provide your app URL.

Setting up a trigger in the CLI

In this example, you use the IBM Cloud CLI to set up a timer trigger in Event Notifications that calls a Code Engine job every 6 hours.

Before you begin, make sure you have the following in your account.

• A Code Engine project.
• A target job within the project.

Complete the following steps to set up the trigger.

1. Create an Event Notifications instance.

   ibmcloud resource service-instance-create "$EVENT_NOTIFICATIONS_INSTANCE_NAME" \
   "$EVENT_NOTIFICATIONS_SERVICE_NAME" "$EVENT_NOTIFICATIONS_PLAN" "$PROJECT_REGION" \
   -g "$PROJECT_RESOURCE_GROUP"
   

2. Create an authorization policy.

   ibmcloud iam authorization-policy-create event-notifications codeengine Writer,Viewer \ 
   --source-service-instance-id $EVENT_NOTIFICATIONS_INSTANCE_ID \
   --target-service-instance-name "${PROJECT_NAME}"
   

3. Create a destination by using your Code Engine job.

   CONFIG_JSON=$(cat <<EOF
   {
     "params": {
       "type": "job",
       "job_name": "${JOB_NAME}",
       "project_crn": "${PROJECT_CRN}"
     }
   }
   EOF
   )
   
   ibmcloud event-notifications destination-create \
     --instance-id "${EVENT_NOTIFICATIONS_INSTANCE_ID}" \
     --name "${DESTINATION_NAME}" \
     --type "ibmce" \
     --description "${DESTINATION_DESCRIPTION}" \
     --config "$CONFIG_JSON"
   

4. Create an Event Notifications topic. Set the topic --topic-timer to 0 */6 * * * for a 6 hour interval.

   ibmcloud event-notifications topic create \
   --name "$TOPIC_NAME" \
   --description "$TOPIC_DESCRIPTION" \
   --service-instance-id "$EVENT_NOTIFICATIONS_CRN" \
   --topic-type timer \
   --topic-timer "$TOPIC_CRON" # Example: "0 */6 * * *" 
   

5. Subscribe to the destination topic.

   ibmcloud event-notifications subscription create \
   --name "$SUBSCRIPTION_NAME" \
   --description "Triggers CE job from topic" \
   --service-instance-id "$EVENT_NOTIFICATIONS_CRN" \
   --topic-id "$TOPIC_ID" \
   --destination-id "$DESTINATION_ID"