Use elastic container instances in Knative

Method 1: Directly create an elastic container instance for a Knative Service

• If the virtual-node-affinity-injection=enabled label is not added to the namespace, you can create an elastic container instance by adding the following configurations when you create resource objects for a Knative Service.
  • Specify the specification of the elastic container instance in the annotation parameter.
  • Specify virtual-kubelet in the nodeAffinity parameter.
  • Specify virtual-kubelet.io/provider in the tolerations parameter.
  Sample template:

  apiVersion: serving.knative.dev/v1
  kind: Service
  metadata:
    name: helloworld-go
    namespace: vk
  spec:
    template:
      metadata:
        annotations:
          k8s.aliyun.com/eci-use-specs: "2-4Gi"
      spec:
        affinity:
          nodeAffinity:
            requiredDuringSchedulingIgnoredDuringExecution:
              nodeSelectorTerms:
              - matchExpressions:
                - key: type
                  operator: In
                  values: 
                  - virtual-kubelet   
        tolerations:
        - key: virtual-kubelet.io/provider
          operator: Exists                
        containers:
        - env:
          - name: TARGET
            value: "Knative"
          image: registry.cn-hangzhou.aliyuncs.com/knative-sample/helloworld-go:73fbdd56

• If the virtual-node-affinity-injection=enabled label is added to the namespace, you need only to specify the specification of the elastic container instance in the annotation field to create an elastic container instance.

  kubectl label namespace vk virtual-node-affinity-injection=enabled

  Sample template:

  apiVersion: serving.knative.dev/v1
  kind: Service
  metadata:
    name: helloworld-go
    namespace: vk
  spec:
    template:
      metadata:
        annotations:
          k8s.aliyun.com/eci-use-specs: "2-4Gi"
      spec:         
        containers:
        - env:
          - name: TARGET
            value: "Knative"
          image: registry.cn-hangzhou.aliyuncs.com/knative-sample/helloworld-go:73fbdd56

Method 2: Automatically create an elastic container instance for a Knative Service by specifying an ECS instance

You can automatically create an elastic container instance for a Knative Service by specifying an Elastic Compute Service (ECS) instance with specified labels in the nodeAffinity parameter. This way, the pod is deployed in both the ECS instance and the elastic container instance.

1. Add a label to the ECS instance. For more information, see Manage node labels.
   The resource-role:ecs label is added to the ECS instance in this example.
2. In the resource object template, set the nodeAffinity parameter.
   Specify the label that is added to the ECS instance and virtual-kubelet in the nodeAffinity parameter.

   Sample template:

   apiVersion: serving.knative.dev/v1
   kind: Service
   metadata:
     name: helloworld-go
   spec:
     template:
       metadata:
         annotations:
           k8s.aliyun.com/eci-use-specs: "2-4Gi"
      spec:
         containerConcurrency: 10
         affinity:
           nodeAffinity:
             requiredDuringSchedulingIgnoredDuringExecution:
               nodeSelectorTerms:
               - matchExpressions:
                 - key: resource-role
                   operator: In
                   values:
                   - ecs
               - matchExpressions:
                 - key: type
                   operator: In
                   values: 
                   - virtual-kubelet
         tolerations:
         - key: virtual-kubelet.io/provider
           operator: Exists                 
         containers:
         - env:
           - name: TARGET
             value: "Knative"
           image: registry.cn-hangzhou.aliyuncs.com/knative-sample/helloworld-go:73fbdd56