apiVersion: v1
kind: Pod
metadata:
	name: myapp-pod
	labels:
		app: myapp
		type: front-end
	annotations:       # misc info (not used by K8s)
		podVersion: 1.2
spec:
	containers:
		- name: nginx-container
			image: nginx

• YAML config file to create and maintain objects in a Kubernetes cluster

• It has 4 top level required fields

  • apiVersion - string

    • depending upon the kind of K8s object being created, use the right API version

    

  • kind - the kind of K8s object being created (string)

  • metadata - metadata about the K8s object being created (dictionary)

    • name - name of the K8s object (string)
    • labels - key-value pairs for grouping K8s objects after creation (dictionary)
    • annotations - used to specify misc information not directly used by K8s but could be used by other tools running on the k8s cluster (dictionary)

  • spec - specifications (dictionary)

    • specific to the K8s object (need to refer the docs)

• Once you have the YAML file, you can deploy the K8s object by kubectl apply -f <filename>.yaml

• To override the Dockerfile CMD, specify the command as args in JSON array format. Similarly, to override the ENTRYPOINT, specify the new docker entrypoint as command in the config file.

  Example:

  FROM Ubuntu
  ENTRYPOINT sleep
  CMD 5
  

apiVersion: v1
kind: Pod
metadata:
	name: ubuntu-sleeper-pod
spec:
	containers:
		- name: ubuntu-sleeper
			image: ubuntu-sleeper
			command: ['sleeper']
			args: ['100']