Kubernetes

https://killercoda.com/playgrounds/scenario/kubernetes

http://labs.play-with-k8s.com/

Local

https://kubernetes.io/releases/download/

https://minikube.sigs.k8s.io/docs/

Install

install kubectl: https://kubernetes.io/docs/tasks/tools/install-kubectl-macos

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/darwin/amd64/kubectl"

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/darwin/amd64/kubectl.sha256"

echo "$(<kubectl.sha256) kubectl" | shasum -a 256 --check

chmod +x ./kubectl

sudo mv ./kubectl /usr/local/bin/kubectl

sudo chown root: /usr/local/bin/kubectl

kubectl version --client

kubectl

install minikube: https://minikube.sigs.k8s.io/docs/start/#what-youll-need

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-darwin-amd64

sudo install minikube-darwin-amd64 /usr/local/bin/minikube

minikube start # Downloads files on the first time

use minikube docker-daemon

minikube docker-env

eval $(minikube -p minikube docker-env)

docker image ls

GCP

https://cloud.google.com/sdk/docs/downloads-versioned-archives

$ gcloud components install kubectl

$ gcloud components update

On GCP create a project here, ensure billing is on and ensure Kubernetes Engine API is switched on.

$ gcloud auth login

$ gcloud config set project PROJECT_ID

Create a k8s cluster:

https://cloud.google.com/sdk/gcloud/reference/container/clusters/create

https://cloud.google.com/compute/docs/machine-types

https://cloud.google.com/compute/docs/regions-zones/

$ gcloud container clusters create --machine-type n1-standard-2 --num-nodes 2 --zone us-central1-b --cluster-version latest k8scluster

Test it is running:

$ kubectl get node # show how many nodes there are

$ kubectl get pods -o wide

$ kubectl config view

$ kubectl get pods -o wide --all-namespaces

$ kubectl describe pod NAME

$ kubectl get pods NAME -o jsonpath='{.spec.containers[*].name}'

$ kubectl get services

$ kubectl logs workerpod

Authenticate the project (https://cloud.google.com/docs/authentication/getting-started)

Put this in your .bash_profile

$ export GOOGLE_APPLICATION_CREDENTIALS="/Users/Ray/Downloads/daskk8s-f92d8191517a.json"

Install helm

...

Install dask kubernetes

$ pip install dask-kubernetes

'Log in the cluster'

$ pip install kubernetes

Deploy the kubernetes configuration onto the cluster:

$ git clone https://github.com/dask/dask-kubernetes.git

$ cd dask-kubernetes/dask_kubernetes

$ kubectl apply -f kubernetes.yaml

Delete the cluster

https://cloud.google.com/kubernetes-engine/docs/how-to/deleting-a-cluster

$ gcloud container clusters delete k8scluster --zone us-central1-b

Azure

https://docs.microsoft.com/en-us/cli/azure/install-azure-cli-windows?view=azure-cli-latest

az aks install-cli (https://docs.microsoft.com/en-us/azure/aks/kubernetes-walkthrough#connect-to-the-cluster)

kubectl version

kubectl config view

kubectl config current-context

kubectl get namespaces

Create a namespace called development

namespace.yaml:

apiVersion: v1

kind: Namespace

metadata:

labels:

kubectl create -f namespace.yaml

Set up the config to find the namespace

kubectl config set-context dev --namespace=development \

--cluster=kubernetes \ # taken from kubectl config current-context

--user=kubernetes-admin

Switch into that namespace

kubectl config use-context dev

kubectl config current-context

Create a pod in this name

pod.yaml:

apiVersion: v1

kind: Pod

metadata:

spec:

containers:

- name: ubuntu

image: ubuntu:trusty

kubectl apply -f pod.yaml

kubectl get pods

kubectl delete pods NAME

kubectl delete --all pods

List container images in pods

kubectl get pods -o jsonpath='{range .items[*]}{"\n"}{.metadata.name}{":\t"}{range .spec.containers[*]}{.image}{", "}{end}{end}' | sort

kubectl get pods --all-namespaces -o jsonpath='{range .items[*]}{"\n"}{.metadata.name}{":\t"}{range .spec.containers[*]}{.image}{", "}{end}{end}' | sort

Create a deployment in this namespace

deployment.yaml:

apiVersion: apps/v1

kind: Deployment

metadata:

labels:

app: dev-app

spec:

replicas: 1

selector:

matchLabels:

app: dev-app

template:

metadata:

labels:

app: dev-app

spec:

containers:

- image: nginx:latest

kubectl apply -f deployment.yml

kubectl get deployment

kubectl describe deployments

Expose this app as a service with 30081 accessible

service.yaml:

apiVersion: v1

kind: Service

metadata:

spec:

selector:

app: dev-app

ports:

- name: http

port: 80

nodePort: 30081

type: NodePort

kubectl get svc

kubectl describe svc service-dev-app

Build a persistant volume

persistentvolumne.yaml:

apiVersion: v1

kind: PersistentVolume

metadata:

spec:

capacity:

storage: 1Gi

accessModes:

- ReadWriteMany

hostPath:

path: "/mnt/data"

reclaimPolicy: Delete

kubectl apply -f persistentvolumne.yaml

Replica sets

See how replica sets are in the cluster

kubectl get rs

kubectl get rs -o wide

kubectl describe rs/NAME

kubectl get rs new-replica-set -o yaml > new-replica-set.yaml

kubectl edit replicaset

kubectl scale --replicas=3 rc/NAME

replicaset.yaml:

apiVersion: apps/v1

kind: ReplicaSet

metadata:

labels:

app: guestbook

tier: frontend

spec:

# modify replicas according to your case

replicas: 3

selector:

matchLabels:

tier: frontend

template:

metadata:

labels:

tier: frontend

spec:

containers:

- name: php-redis

image: gcr.io/google_samples/gb-frontend:v3