Building Enterprise JavaScript Applications

Running pods declaratively with kubectl apply

With the Deployment manifest ready, we can run kubectl apply to update the desired state of our cluster:

$ kubectl apply -f manifests/elasticsearch/deployment.yamldeployment.apps "elasticsearch" created

This will trigger a set of events:

1. kubectl sends the Deployment manifest to the Kubernetes API server (kube-apiserver). kube-apiserver will assign it a unique ID, and adds it on to etcd.
2. The API server will also create the corresponding ReplicaSet and Pod Objects and add it to etcd.
3. The scheduler watches etcd and notices that there are Pods that have not been assigned to a node. Then, the scheduler will make a decision about where to deploy the Pods specified by the Deployment.
4. Once a decision ...