Helm contd..

Sprig functions

• Since helm uses go templating we can use the functions

Built in objects

• Refer Here

Cheatsheet

• Refer Here for helm cheatsheet
• Refer Here for the changes done to include label
• Refer Here for changes with looping constructs
• If helm chart is giving issues try generating normal yaml files helm template my-release ./path-to-local-chart --output-dir ./output-folder

Persistent Volumes in K8s

• K8s supports 3 types of storage volumes
  • block storage (aws ebs, azure managed disk …)
  • nfs storage (aws efs, azure files, netapp )
  • local storage
• K8s uses CSI (Container Storage Interface)
• K8s has Persistent volumes (PV) Refer Here. PV can exist even after pod is deleted.
• K8s supports two ways of using PVs
  • Static provisioning
  • Dynamic Provisioning
• K8s Pod will create PersistentVolumeClaim (PVC) which is kind of request and k8s with the help of CSI driver will create a volume (PV) and that gets bound to a pod.
• Lets consider the following mysql pod

apiVersion: v1
kind: Pod
metadata:
  name: mysql
  labels:
    app: mysql
spec:
  containers:
  - name: mysql
    image: mysql:9
    env:
    - name: MYSQL_ROOT_PASSWORD
      value: "password"   # Replace with your desired root password
    ports:
    - containerPort: 3306

• Access modes: Refer Here
• Refer Here for azure example