This notes is for the course Kuberenetes for absolute beginners

Kubernetes definition file

A Kubernetes definition file always contains 4 top level fields. These are required fields

apiVersion:
kind:
metadata:
.
.
.
spec:

1. apiVersion - Version of k8s API
2. kind - type of object (pod, replica-set, service, deployment)
3. metadata - data about the object (name and label), it is in the form of a dictionary. Here name is a string value and labels is a dictionary. Labels are useful to identify objects at a later point in time.

metadata:
  name: myapp-pod
  labels:
    app: myapp

4. spec - (specification) where we provide additional information to k8s pertaining to that object. Spec is a dictionary, we can add properties to it, containers in this example, which is a list. The reason this property is a list is because the PODs can have multiple containers within them.

spec:
  containers:
    - name: nginx-container
      image: nginx

Few of the kubectl commands

kubectl create -f pod-definition.yml
kubectl get pods
kubectl describe pods