Container Service for Kubernetes:Use the Kubernetes API

Obtain cluster credentials in the kubeconfig file

1. Log on to the ACK console.
2. In the left-side navigation pane of the ACK console, click Clusters.
3. On the Clusters page, find the cluster that you want to manage and click the name of the cluster or click Details in the Actions column. The details page of the cluster appears.
4. On the cluster details page, click the Connection Information tab. You can find the cluster credential in the kubeconfig file. Copy the content of the kubeconfig file and save it to your on-premises machine.
5. Run the following commands to retrieve information about the certificate authority (CA), the private key, and the API server:

   cat  ./kubeconfig |grep client-certificate-data | awk -F ' ' '{print $2}' |base64 -d > ./client-cert.pem
   cat  ./kubeconfig |grep client-key-data | awk -F ' ' '{print $2}' |base64 -d > ./client-key.pem
   APISERVER=`cat  ./kubeconfig |grep server | awk -F ' ' '{print $2}'`

Use cURL to call the Kubernetes API

Run the following command to query all namespaces in the cluster:

curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/api/v1/namespaces

• Common operations to manage pods

  Run the following command to query all pods in the default namespace:

  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/api/v1/namespaces/default/pods

  Run the following command to create a pod (JSON format):

  cat nginx-pod.json
  {
      "apiVersion":"v1",
      "kind":"Pod",
      "metadata":{
          "name":"nginx",
          "namespace": "default"
      },
      "spec":{
          "containers":[
              {
                  "name":"nginx",
                  "image":"nginx:alpine",
                  "ports":[
                      {
                          "containerPort": 80
                      }
                  ]
              }
          ]
      }
  }
  
  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/api/v1/namespaces/default/pods -X POST --header 'content-type: application/json' -d@nginx-pod.json

  Run the following command to create a pod (YAML format):

  cat nginx-pod.yaml
  apiVersion: v1
  kind: Pod
  metadata:
    name: nginx
    namespace: default
  spec:
    containers:
    - name: nginx
      image: nginx:alpine
      ports:
      - containerPort: 80
  
  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/api/v1/namespaces/default/pods -X POST --header 'content-type: application/yaml' --data-binary @nginx-pod.yaml

  Run the following command to query the status of a pod:

  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/api/v1/namespaces/default/pods/nginx

  Run the following command to query the log data of a pod:

  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/api/v1/namespaces/default/pods/nginx/log

  Run the following command to collect metrics of a pod by using the metric-server API:

  --certcurl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/apis/metrics.k8s.io/v1beta1/namespaces/default/pods/nginx

  Run the following command to delete a pod:

  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/api/v1/namespaces/default/pods/nginx -X DELETE

• Common operations to manage Deployments

  Create a Deployment. The following YAML template is an example:

  cat nginx-deploy.yaml
  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: nginx-deploy
    labels:
      app: nginx
  spec:
    replicas: 2
    selector:
      matchLabels:
        app: nginx
    template:
      metadata:
        labels:
          app: nginx
      spec:
        containers:
        - name: nginx
          image:  nginx:alpine
          ports:
          - containerPort: 80
          resources:
            requests:
              cpu: "2"
              memory: "4Gi"
  
  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/apis/apps/v1/namespaces/default/deployments -X POST --header 'content-type: application/yaml' --data-binary @nginx-deploy.yaml

  Run the following command to query a Deployment:

  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/apis/apps/v1/namespaces/default/deployments

  Run the following command to update a Deployment by modifying the number of replicated pods:

  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/apis/apps/v1/namespaces/default/deployments/nginx-deploy -X PATCH -H 'Content-Type: application/strategic-merge-patch+json' -d '{"spec": {"replicas": 4}}'

  Run the following command to update a Deployment by changing the container image:

  curl --cert ./client-cert.pem --key ./client-key.pem -k $APISERVER/apis/apps/v1/namespaces/default/deployments/nginx-deploy -X PATCH -H 'Content-Type: application/strategic-merge-patch+json' -d '{"spec": {"template": {"spec": {"containers": [{"name": "nginx","image": "nginx:1.7.9"}]}}}}'