Kubernetes

Installing Virtualbox

virtualbox or the summary:

#!/bin/bash
wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
echo "deb [arch=amd64] http://download.virtualbox.org/virtualbox/debian bionic contrib" | sudo tee /etc/apt/sources.list.d/virtualbox.list
sudo apt-get update
sudo apt update
sudo apt install linux-headers-$(uname -r) dkms
sudo apt-get install virtualbox-6.0
cd ~/
wget https://download.virtualbox.org/virtualbox/6.0.0/Oracle_VM_VirtualBox_Extension_Pack-6.0.0.vbox-extpack

AWS Kubernetes EKS

The first command creates a new context entry in ~/.kube/config the second command displays the available contexts, then the third command changes the contexts to the one provided context-name from the output of the second command. The fourth command displays the now active context.

aws eks --region us-east-1 update-kubeconfig --name $(StackName)
kubectl config get-contexts
kubectl config use-context __Name from get-contexts__
kubectl config current-context

Alternatively a less manual approach. (Ust the -r flag in jq to get the string without quotes) Make sure to use the aws profile/IAM User that created the cluster or assign the create-cluster privileges to your user.

FIRSTCLUSTER=$(aws eks list-clusters | jq -r '."clusters"[]') 
aws eks --region us-east-1 update-kubeconfig --name $FIRSTCLUSTER
THISCONTEXT=${/kubectl config get-contexts | grep \* | awk '{ print $2 }'}
kubectl config use-context $THISCONTEXT

Kubernetes Objects

Deployment

Deployments create Pods from Images. Create Deployments from deployment yaml files, like

kubectl create -f deployment.yaml

To allow images being pulled from AWS ECR in minikube docs

minikube addons configure registry-creds
minikube addons enable registry-creds

The creds have to be referenced in the yaml like this:

imagePullSecrets:
  - name: awsecr-cred
containers:
    image: 123456789123.dkr.ecr.us-east-1.amazonaws.com/flaskpy:latest
    ports:

Next services

Services

Services are used to expose Deployments internally or publicly

NodePort

Nodeports are used to expose a Service on a Node outside to local Kubernetes cluster. This can be used for Development on Minikube.

ClusterIP

Cluster IP Services are used for Deployments that need to talk to other Services inside Kubernetes but not the outside world

Loadbalancer

Loadbalancer Services are only available on supported Cloud Service Provicers. A Loadbalancer Service creates an object in the Cloud e.g. an AWS Loadbalancer to expose a Kubernetes Deployment publicly through AWS Route53.