CloudOps Orchestration Service:Create an event-trigger O&M task

Cloud service events are status changes of cloud service resources. For example, an Elastic Compute Service (ECS) instance is restarted abnormally or released, a snapshot is created for an ECS instance, or O&M operations will be performed on an ECS instance. For more information, see Event monitoring overview. CloudOps Orchestration Service (OOS) supports O&M tasks triggered by cloud service events. In an event-triggered O&M task, you can specify a template to be executed when the specified event occurs. An event-triggered O&M task keeps running to listen to the specified cloud service events until you cancel the task.

To create an event-triggered O&M task, follow these steps:

1. Set a trigger rule to monitor the cloud service event that you concern.

2. Select a template to be executed.

3. Set parameters for executing the template.

Set a trigger rule to monitor the cloud service event that you concern. The following table describes the parameters for a trigger rule.

Details of cloud service events are described in JSON texts. Fields in event details vary with the event type. You can filter event details based on the fields. Take the notifications for ECS instance status changes as an example. The event details indicated by the content field in the event message body are in the following format:

{
    "resourceId": "i-bp1ecr********5go2go",  
    "resourceType": "ALIYUN::ECS::Instance", 
    "state": "Running"                       
}

The resourceId field in the event details indicates the ID of the ECS instance whose status was changed. An ECS instance can be in the pending, starting, running, stopping, stopped, or deleted state.

Rules for filtering event details are also described in JSON texts. In such a rule, use a key in the event details and set the value to the corresponding value or values in the event details.For example, if you want to configure an O&M task that is triggered when an instance is stopped, set the rule as follows:

{
  "state": "Stopped"
}

If you want to configure an O&M task that is triggered when the i-abcde instance is stopped or released, set the rule as follows:

{
  "resourceId": "i-abcde",
  "state": ["Stopped", "Deleted"]
}

A sample text of event details is shown on the right of the Event Details Filtering Rule field for reference.

Select a template to be executed when the specified cloud service event occurs.

In this step, select Extract Value from Message Body or Fixed Value. If you select Fixed Value, the template will be executed based the parameter values that you set. If you select Extract Value from Message Body, you can use jQuery expressions to extract values from event message bodies for executing the template.

To extract values from event message bodies, use jQuery expressions in the $.Parameter name format. Take the message body of notifications for ECS instance status changes as an example. You can use the $.content.resourceId expression to extract the value of the resourceId parameter,and use the $.regionId expression to extract the value of the regionId parameter.

The following table describes the parameters that can be extracted from all event message bodies.

The following figure shows an example of extracting values from an alert message body.

You can also set fixed parameter values for executing the template. The method is similar to that for common templates.