Kubernetes objects like pods, replicaset, statefulset, services, etc.. can be created in Imperative and Declarative mode.
Imperative mode
- In the imperative mode of creating Kubernetes objects, the objects are created with Kubernetes's kubectl commands.
- One advantage of imperative mode is we can create and delete objects quickly as it is a single-line command execution
- In imperative mode, we use
kubectl create
Below are the some of the example commands used for creating various Kubernetes objects in the imperative mode
# service creation kubectl create service clusterip linuxdatahub--tcp=80:80 # Deployment creation kubectl create deployment data-node --image=<image-name> #Create jobs kubectl create job <jobname> --image=<image-name>
Declarative mode:
- In Declarative mode, the Kubernetes objects are created with a manifest YAML file.
- Users need to prepare manifest YAML with required mandatory parameters and need to be used with
kubectl apply - Manifest file content change according to the objects, but the template of the manifest is common, below snippet shows the template
apiVersion:
kind:
metadata:
name:
labels:
app:
spec:
During the course of the tutorial, we will be using both imperative and declarative method
Official Kubernetes doc on imperative and declarative methods can be found here