If you want to use Microservices Engine (MSE) Ingresses to expose your services in a ACK Serverless cluster, you must first authorize the MSE Ingress controller to access MSE. This topic describes how to authorize the MSE Ingress controller in an ACK Serverless cluster to access MSE.
Step 1: Install the MSE Ingress controller
Method 1: Install the MSE Ingress controller when you create a cluster
On the Component Configurations wizard page, select MSE Ingress in the Ingress section. For more information about ACK Serverless cluster parameters, see Create an ACK Serverless cluster. 
Method 2: Install the MSE Ingress controller for an existing cluster on the Add-ons page
Log on to the ACK console. In the left-side navigation pane, click Clusters.
On the Clusters page, click the name of the cluster that you want to manage and choose in the left-side navigation pane.
- On the Add-ons page, click the Networking tab. Find MSE Ingress Controller and click Install.
- In the Install MSE Ingress Controller dialog box, select or clear Cascade Delete SLB Instance and click OK.
Step 2: Authorize the MSE Ingress controller to access MSE
On the Cloud Resource Access Authorization page, click Confirm Authorization Policy.
After the authorization is completed, the MSE Ingress controller can assume the Resource Access Management (RAM) role AliyunMSEForECIRole to access MSE.
Log on to the ACK console. In the left-side navigation pane, click Clusters.
On the Clusters page, click the name of the cluster that you want to manage and choose in the left-side navigation pane.
In the upper part of the Deployments page, select All Namespaces from the Namespace drop-down list. Enter ack-mse-ingress-controller in the search box and click the search icon. After ack-mse-ingress-controller appears on the page, choose in the Actions column. In the message that appears, click Confirm.
After you redeploy ack-mse-ingress-controller, click ack-mse-ingress-controller on the Deployments page. Then, verify that the pod displayed on the Pods tab is in the Running state.