YAML Definition File

YAML Definition File


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

notion image

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

Dockerfile


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

pod.yaml