Custom Action-Provider

An action-provider is an implementation of a Keptn-service with a dedicated purpose. This type of service is responsible for executing a remediation action and therefore might even use another tool. The Keptn CloudEvents an action-provider has to subscribe to is:

• sh.keptn.event.action.triggered

Write your custom Action-provider

Like a Keptn-service, an action-provider has the following characteristics:

• has a subscription to an event (i.e., sh.keptn.event.action.triggered)
• sends a started event to inform Keptn about receiving the event and acting on it
• processes functionality and can therefore leverage additional tools, e.g., through their REST interface
• sends a finished event to inform Keptn about its execution status and the result

Subscription to Keptn event

An action-provider starts working, when receiving a Keptn CloudEvent of type:

• sh.keptn.event.action.triggered

Next to meta-data such as project, stage, or service name, the event contains information about the action to execute. For more details, please see the specification here and take a look at the example:

{
  "type": "sh.keptn.event.action.triggered",
  "specversion": "1.0",
  "source": "https://github.com/keptn/keptn/remediation-service",
  "id": "f2b878d3-03c0-4e8f-bc3f-454bc1b3d79d",
  "time": "2019-06-07T07:02:15.64489Z",
  "contenttype": "application/json",
  "shkeptncontext": "08735340-6f9e-4b32-97ff-3b6c292bc509",
  "data": {    
    "action": {
      "name": "Toggle feature flag",
      "action": "featuretoggle",
      "description": "Toggle feature flag PromotionCampaign from ON to OFF.",
      "value": {
        "PromotionCampaign": "off"
      }
    },
    "problem": {
      // contains problem details
    },
    "project": "sockshop",
    "stage": "production",
    "service": "carts"
  }
}

Distributor:

• To subscribe your action-provider to the sh.keptn.event.action.triggered event, please follow Subscription to Keptn event.

Functionality

After receiving the sh.keptn.event.action.triggered event, an action-provider must perform following tasks:

1. Process the incoming Keptn CloudEvent to receive meta-data such as project, stage, and service name. Besides, the action and value properties are required.

2. Decide based on the action property whether the action is supported. If the action is not supported, no further task is required.

3. Send a started event: If the action is supported, send a start event of type: sh.keptn.event.action.started. This CloudEvent informs Keptn that a service takes care of executing the action.

4. Execute the implemented functionality. At this step, the action-provider can make use of another automation tool.

5. Send a finished event: Send a finished event of type: sh.keptn.event.action.finished with the added properties:

• Add to the header of the event:

  • triggeredid: The value of this property is the id of the sh.keptn.event.action.triggered event.

• Add to the data block at least a value for status and result in data.action:

  • status: [succeeded, errored, unknown] - The status of the task execution
  • result: [pass, failed] - The result of a successful task execution

{
  "type": "sh.keptn.event.action.finished",
  "specversion": "1.0",
  "source": "https://github.com/keptn/keptn/unleash-service",
  "id": "ggb878d3-03c0-4e8f-bc3f-454bc1b3d888",
  "time": "2019-06-07T07:02:15.64489Z",
  "contenttype": "application/json",
  "shkeptncontext": "08735340-6f9e-4b32-97ff-3b6c292bc509",
  "triggeredid": "2b878d3-03c0-4e8f-bc3f-454bc1b3d79d",      # <- add triggeredid
  "data": {
    "action": {                                              # <- add data.action
      "status": "succeeded",
      "result": "pass"
    },
    "project": "sockshop",
    "service": "carts",
    "stage": "staging",
    "labels": {
      "testId": "4711",
      "buildId": "build-17",
      "owner": "JohnDoe"
    }
  }
}

Deploy Action-provider with distributor

A default deployment manifest is provided in the keptn-service-template-go template, see: deploy/service.yaml.

• Change the deployment manifest for your action-provider and the apply it to the Kubernetes cluster where Keptn is running:

kubectl apply -f service.yaml -n keptn