vbmade2000/k8s-api-tutorial

Simple Walkthrough of Kubernetes API

Kubernetes API Walkthrough

Simple walkthrough of Kubernetes API

You can also execute the shell script to perform these steps.

Install JQ before trying the commands. Make sure that you have access to a Kubernetes cluster.

Verify Kubernetes setup

kubectl cluster-info
kubectl component-status

Configure the proxy

kubectl proxy --port=8000&

Open the Swagger UI in the browser

open http://localhost:8000/swagger-ui/

Invoke simple Kubernetes API

curl http://localhost:8000/api

cURL command equivalent to 'kubectl get nodes'

curl -s http://localhost:8000/api/v1/nodes | jq '.items[] .metadata.labels'

Create a Nginx Pod definition

cat > nginx-pod.json <<EOF
{
    "kind": "Pod",
    "apiVersion": "v1",
    "metadata":{
        "name": "nginx",
        "namespace": "default",
        "labels": {
            "name": "nginx"
        }
    },
    "spec": {
        "containers": [{
            "name": "nginx",
            "image": "nginx",
            "ports": [{"containerPort": 80}],
            "resources": {
                "limits": {
                    "memory": "128Mi",
                    "cpu": "500m"
                }
            }
        }]
    }
}
EOF

Create a Service definition to expose Nginx Pod

cat > nginx-service.json <<EOF
{
    "kind": "Service",
    "apiVersion": "v1",
    "metadata": {
        "name": "nginx-service",
        "namespace": "default",
        "labels": {"name": "nginx"}
    },
    "spec": {
        "ports": [{"port": 80}],
        "selector": {"name": "nginx"}
    }
}
EOF

Create the Pod object

curl -s http://localhost:8000/api/v1/namespaces/default/pods \
-XPOST -H 'Content-Type: application/json' \
[email protected] \
| jq '.status'

Create the Service object

curl -s http://localhost:8000/api/v1/namespaces/default/services \
-XPOST -H 'Content-Type: application/json' \
[email protected] \
| jq '.spec.clusterIP'

Verify the Pod with 'kubectl get pods'

kubectl get pods

Verify the Service with 'kubectl get svc'

kubectl get svc

Access Nginx default page through the proxy

curl http://localhost:8000/v1/proxy/namespaces/default/services/nginx-service/

Delete the Pod

curl http://localhost:8000/api/v1/namespaces/default/services/nginx-service -XDELETE

Delete the Service

curl http://localhost:8000/api/v1/namespaces/default/pods/nginx -XDELETE