Important Concepts of K8s

• Namespace: In k8s we can create virtual clusters using namespace.

kubectl get namespace

• api-resources: All the different resources available in K8s

 kubectl api-resources
 

Workloads

Pod

• Refer Here for Pod Lifecycle

• init-containers: These are containers which will execute before the main containers. Init containers are supposed to executing only for a certain time.

  • Lets assume we have a Podspec in which
    • init-contiainer-1:
      • Here you have written ping -c 4 google.com
    • init-container-2
      • Here you have written ping -c 4 qt.artifactory.com
    • jenkins (main)

Controllers

• In controllers, We control Workload objects

Replication Controller

• In Replication Controller we can set number of pods as the desired state.

Daemon Set

• Creates one pod on every node in K8s cluster