kustomize-samples

Some sample Kubernetes projects using Kustomize

Install Kustomize

Install the customize tool as per your OS using the official guide below

https://kubectl.docs.kubernetes.io/installation/kustomize/

I used below since im using MacOS

brew install kustomize

However, it is not mandatory to install Kustomize as above since, K8S v1.14, Kubectl also natively supports the management of Kubernetes objects using a kustomization file.

Check the final code before executing

Run the below command in the location of kustomization.yaml file

   kustomize build <path>

This will output the parsed kubernetes manifests on to the terminal itself, so that you can validate them before "kubectl apply"

Samples Provided

• Sample1 : Simple kustomization of a nginx deployment that adds a label

     kubectl apply -k sample1/
     kubectl get all -n test
  

• Sample2 : Like similar to Sample1, adds few more additional common transformers like namespace and a prefix to the deployment

     kubectl apply -k sample2/
     kubectl get all -n test
  

• Sample 3 : Introduces Strategic-Merge patch that changes the replica count of the nginx deployments and also increases the memory resource allocations

     kubectl apply -k sample3/
     kubectl get all -n test
  

• Sample 4 : Organize K8S manifests in to a app specific structures

     kubectl apply -k sample4/
     kubectl get all -n test
  

• Sample 5: Organize K8S manifests in to a app specific structures with multiple manifests in each application specific directories

     kubectl apply -k sample4/
     kubectl get all -n test
  

• Sample 6: Change the image versions

     kubectl apply -k sample4/
     kubectl get all -n test
  
     kubectl describe deployment redis-db -n test | grep Image
     kubectl describe deployment nginx -n test | grep Image
  

• Sample 7: Change specific values of specific kubernetes entities with Patching. Patches are defined inline within the kustomization.yaml file

     kubectl apply -k sample7/
     kubectl get all -n test
  
     kubectl describe deployment nginx -n test | grep Name:
  

• Sample 8: Change specific values of specific kubernetes entities with Patching, and patches defined in separate files

     kubectl apply -k sample8/
     kubectl get all -n test
  
     kubectl describe deployment nginx -n test | grep Replicas:
  

• Sample 9: Implement real world example using Overlays. Overlays implement the concept of configurations based on separate environments such as dev/statging and pod. Change the values as requered in sample9/overlays//patches directory

     kubectl apply -k sample9/overlays/staging
     kubectl get all -n test
     kubectl describe deployment redis -n test | grep Replicas:
  
     kubectl apply -k sample9/overlays/prod
     kubectl get all -n prod
     kubectl describe deployment redis -n prod | grep Replicas:
  

Prerequisites

• A running K8S cluster with Kubectl context set properly
• K8S test namespace

   kubectl create namespace test
   kubectl create namespace prod