Kubernetes playground on local PC Mac OS

Refer to cka.md for how to setup everything manually.

Task List

• Setup 3 VMs via Vagrant and VirtualBox
• Test #1 Associate PV=>PVC=>Pod
• Test #2 Associate PV => Statefulset via volumeClaimTemplates
• Test #3 DB statefulset
• Test #4 Blue/Green deployment
• Test #5 Canary deployment

Setup 3 VMs via Vagrant and VirtualBox

• Install Virtuabox by downloading the package from Oracle web, see below command for Mac PC

brew install virtualbox

• Install Vagrant by downloading the package from Hashcorp web https://learn.hashicorp.com/vagrant/getting-started/

• Provision a test website https://learn.hashicorp.com/vagrant/getting-started/provisioning

• Backup kube config

• Clone test repo cd ~/proj/k8s/ git clone https://github.com/jimmycgz/kubernetes.git

• Follow this video to setup k8s cluster using vagrantfile https://www.youtube.com/watch?v=wPdIBeWJJsg&t=1145s Steps are described here: https://github.com/jimmycgz/kubernetes/blob/master/docs/install-cluster-centos-7.md

• Access this cluster via host cd ~/.kube mv config bkp-conf-paytm scp vagrant@kmaster.example.com:.kube/config cf-local-vagrant k config view --flatten > cf-merged cat cf-merged cp cf-merged config

#Switch context by docker icon in Mac OS kubectl get nodes

Get faimiliar with PV/PVC/Statefulset

Storage management workflow for TEST #1:

Mac OS local folder of Vagrant provision 
=> /vagrant on Vagrant VM as k8s node local folder
=> PV named manual-mnt-local
=> PVC for nginx pod

Test #1 Associate PV=>PVC=>Pod

1. mount pv folder on vagrant provision folder

vagrant halt
mkdir ~/proj/k8s/kubernetes/vagrant-provisioning/local-vol
mkdir ~/proj/k8s/kubernetes/vagrant-provisioning/local-vol/data
cd ~/proj/k8s/kubernetes/vagrant-provisioning/local-vol
echo 'test local pv' >index.html
echo 'test data' >data/test-data.txt
vagrant up
vagrant ssh kworker1
ll /vargant

2. create pv volume k8s on host pc Follow https://www.bogotobogo.com/DevOps/Docker/Docker_Kubernetes_PersistentVolumes_PersistentVolumeClaims.php
3. create pvc and associate with pv
4. Test pvc on nginx pod

k apply -f pvc-pod.yaml
kubectl exec -it task-pv-pod -- /bin/bash
apt-get update
apt-get install curl
curl localhost

follow below post if get stuck deleting old pv/pvc

https://stackoverflow.com/questions/51358856/kubernetes-cant-delete-persistentvolumeclaim-pvc

 k patch pvc task-pv-claim -p '{"metadata":{"finalizers": []}}' --type=merge

Test #2 Associate PV => Statefulset via volumeClaimTemplates

Storage management workflow:

Mac OS local folder of Vagrant provision 
=> /vagrant on Vagrant VM as k8s node local folder
=> PV named manual-mnt-local
=> PVC for statefulset nginx
=> Nginx pod relica

Follow below docs: #Single static pv/pvc https://www.bogotobogo.com/DevOps/Docker/Docker_Kubernetes_StatefulSet.php

#Dynamic multiple pv/pvc https://www.magalix.com/blog/kubernetes-statefulsets-101-state-of-the-pods#:~:text=A%20StatefulSet%20is%20another%20Kubernetes,pods%20with%20well%2Ddefined%20names. https://docs.openshift.com/container-platform/3.5/install_config/storage_examples/storage_classes_dynamic_provisioning.html

Delete the pvc and pv created in Test #1

k patch pvc task-pv-claim -p '{"metadata":{"finalizers": []}}' --type=merge
k delete pvc task-pv-claim
kg pv
#PV status should be releasing

k delete pv task-pv-volume

Re-use the pv from Test #1 and associate it to statefulset nginx

k apply -f pv-volume.yaml
k apply -f web-stateful-pvc.yaml
k apply -f pv-volume.yaml 
kg pv
#PV status should be available

k apply -f web-stateful-pvc.yaml
kg pods
kubectl exec -it web-0 -- /bin/bash
      apt-get update
      apt-get install curl
      curl localhost
      #Outcome:test local-volume mnt from vagrant vm, associated from vagrant provision folder on local pc

Test #3 DB statefulset

PostgreSQL cluster using statefulsets https://kubernetes.io/blog/2017/02/postgresql-clusters-kubernetes-statefulsets

Test #4 Blue/Green deployment

Refer to the light weight approach: https://www.ianlewis.org/en/bluegreen-deployments-kubernetes Basically switch over k8s service via spec.selector to different labels(like name and version)

apiVersion: v1
kind: Service
metadata: 
  name: nginx
  labels: 
    name: nginx
spec:
  selector: 
    name: nginx
    version: "1.11" # switch between 1.10 and 1.11
    ...

Test #5 Canary deployment

Refer to the light weight approach: https://kubesphere.io/docs/quick-start/ingress-canary/ Solution is to use Ingress-Nginx Annotation to define the percentage of canary-weight

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: canary
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-weight: "10"
...