Container Service for Kubernetes:Schedule pods to ACS using virtual nodes

How to use the computing power of ACS in ACK One registered clusters

Container Compute Service (ACS) is a cloud computing service that provides container compute resources that comply with the container specifications of Kubernetes. ACS adopts a layered architecture to implement Kubernetes control and computing power. The compute resources layer schedules and allocates resources to pods. The Kubernetes control layer manages workloads, such as Deployments, Services, StatefulSets, and CronJobs.

The computing power of ACS can be implemented in Kubernetes clusters by using virtual nodes. This way, Kubernetes clusters are empowered with high elasticity and are no longer limited by the computing capacity of cluster nodes. After you use ACS to take over infrastructure management for pods, the Kubernetes cluster no longer needs to schedule or launch individual pods. In addition, the Kubernetes cluster no longer needs to be concerned about the resources of underlying VMs. ACS can meet the resource requirements of pods at any time.

In ACK One registered clusters, you must install the ack-virtual-node component to deploy virtual nodes and create ACS pods. If you need to scale out your cluster, you can create ACS pods on virtual nodes without the need to plan the resource capacities of the nodes. ACS pods can communicate with pods on physical nodes in the cluster. To efficiently use resources, shorten the scaling time, and reduce costs, we recommend that you schedule specific workloads that run for an extended period of time and have elastic traffic to virtual nodes. As the number of business traffic decreases, the pods on the virtual node can be quickly released to reduce usage costs. Pods on virtual nodes run in a secure and isolated environment that is built on top of ACS. In this case, a pod is referred to as an ACS pod. For more information, see Overview of registered clusters.

Prerequisites

• An ACK One registered cluster is created and connected to a data center or a Kubernetes cluster of another cloud service provider (Kubernetes 1.24 or later is recommended).

• The ACK virtual node component is installed and the version of the component is 2.13.0 or later. For more information, see Grant RAM permissions to ack-virtual-node and Install ack-virtual-node.

How to use the CPU computing power of ACS in ACK One registered clusters

After you install the required version of ACK Virtual Node or update the component to version 2.13.0 or later, you can create ACS pods and elastic container instances.

To use the computing power of ACS in an ACK cluster, perform the following steps:

1. Create a file named nginx.yaml that contains the following content:

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx
     labels:
       app: nginx
   spec:
     replicas: 2
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         labels:
           app: nginx 
           alibabacloud.com/acs: "true" # Use the computing power of ACS.
           alibabacloud.com/compute-class: general-purpose # The compute class of the ACS pod.
           alibabacloud.com/compute-qos: default # The QoS class of the ACS pod.
       spec:
         containers:
         - name: nginx
           image: mirrors-ssl.aliyuncs.com/nginx:stable-alpine
           ports:
             - containerPort: 80
               protocol: TCP 
           resources:
             limits:
               cpu: 2
             requests:
               cpu: 2

2. Run the following command to create an NGINX application:

   kubectl apply -f nginx.yaml 

3. Run the following command to check whether the NGINX application is deployed:

   kubectl get pods -o wide

   Expected output:

   NAME                     READY   STATUS    RESTARTS   AGE     IP               NODE                            NOMINATED NODE   READINESS GATES
   nginx-54bcbc9b66-****   1/1     Running   0          3m29s   192.168.XX.XXX   virtual-kubelet-cn-shanghai-l   <none>           <none>
   nginx-54bcbc9b66-****   1/1     Running   0          3m29s   192.168.XX.XXX   virtual-kubelet-cn-shanghai-l   <none>           <none>

   The command output indicates that the two pods are deployed on nodes that have the type=virtual-kubelet label, which is specified by the nodeSelector parameter in the Deployment configurations.

4. Run the following command to query the details of the pod created for the NGINX application:

   kubectl describe pod nginx-54bcbc9b66-**** 

   Expected output:

   Annotations:  ProviderCreate: done
                 alibabacloud.com/instance-id: acs-uf6008giwgjxlvn*****
                 alibabacloud.com/pod-ephemeral-storage: 30Gi
                 alibabacloud.com/pod-use-spec: 2-2Gi
                 kubernetes.io/pod-stream-port: 10250
                 network.alibabacloud.com/enable-dns-cache: false
                 topology.kubernetes.io/region: cn-shanghai

   The command output indicates that the configurations of the pod include the alibabacloud.com/instance-id: acs-uf6008giwgjxlvn***** annotation. This indicates that the pod is an ACS pod.

How to use the GPU computing power of ACS in ACK One registered clusters

The procedure for using ACS GPU compute power is similar to that for using ACS CPU compute power. However, you also need to ensure that the scheduling components meet the version requirements and add some additional configurations.

...     
     labels:
        # Add labels to request ACS GPU resources.
        alibabacloud.com/compute-class: gpu     #Set to gpu if GPU compute power is used.
        alibabacloud.com/compute-qos: default   #The QoS class, which is the same as regular ACS compute power.
        alibabacloud.com/gpu-model-series: example-model  # The GPU model. Specify the actual model that you use, such as T4.
...