【한글자막】 DevOps (데브옵스) : Kubernetes 완전 정복

What is kubernetes, why would you use it, what benefits does it give you

On Kubernetes you run containers. In this lecture you'll learn what containers are all about.

Kubernetes can run almost anywhere. You can run it on-premise or in the cloud.

This lectures explains what minikube is, a piece of software that can help you run kubernetes locally.

This demo shows you how to run Kubernetes using Minikube.

As an alternative to Minikube, you can install kubernetes using the official docker client for Mac / Windows

The difference between Minikube vs Docker client vs Kops vs Kubeadm: which one to use when

An introduction to Kops - Kubernetes Operations. Software to provision and manage Kubernetes on AWS.

Kops only works on Mac / Linux, so you'll need to setup a vagrant box to run kops. If you are running already MacOS or Linux, and you don't want to be working in a VM, you can skip this step.

You first need to open an AWS account, add an IAM user for kops and setup DNS using route53

The DNS settings need to be correct for your kubernetes cluster to work. Follow this lecture if you have issues with your DNS settings.

Once the AWS setup is complete, you can use kops to setup the Kubernetes cluster on AWS

Kubernetes only runs containers. In this lecture you learn how to build your application in a container.

In this demo I show you how to build a NodeJS example app in a container.

Once you have built a container, you need to put it on a registry, so Kubernetes can download it. You have public and private registries. Putting a container on a public registry is free.

In this demo I show you how to push the container with our app to Docker Hub

THis lecture explains how to run a first application on Kubernetes

Once the first app is available on Docker Hub, I show you how to run this app on our Kubernetes cluster

In this demo I show you some useful commands you can use to manage your containers on Kubernetes

If you're running your cluster on AWS, you can create a LoadBalancer (AWS ELB) for your application

In this demo I show you how to add an ELB (Elastic Load Balancer) to the example app

In this lecture I recap the most important concepts from the first section

In this lecture I explain the Kubernetes node architecture

You can use the replication controller to spin up multiple instances of your application

This demo shows you how to spin up multiple instances of your application

Deployment objects allow a better abstraction of an application running on Kubernetes. You can update your application version easily and roll-back if something goes wrong.

In this demo I show you how our example application can be a deployment.

Exposing our application for external traffic can be done using services

In this demo I show you how to expose our example app

Labels can be used to tag objects

Labels together with NodeSelectors can be used to run pods on a specific node

Healthchecks can be used to periodically check whether our app in the pod is still working

In this demo I show you how to use healthchecks

Application credentials (for instance to access a database) can be stored in secrets.

Credentials can be mounted as a volume in a pod. This demo shows you how to do that.

First attempt to run a wordpress on Kubernetes. In a later version I'll show you a better way of running Wordpress on Kubernetes

Kubernetes also has a Web UI, a dashboard that makes it easy to use kubernetes

Demo explaining how to add the web UI in kops

In this brief demo I give an overview how to use the dashboard

You can do service discovery using DNS.

This is a demo showing you how service discovery works

Containers are immutable. You can still use ConfigMaps for dynamic configuration data that needs to be present on the container.

In this demo I show you how to use ConfigMap to create a custom configuration file for a standard nginx container

Ingress controller allows you to have a reverse proxy / load balancer within your Kubernetes cluster and without using an external load balancer.

In this demo I show you how to use the built-in kubernetes ingress controller

If you want to run stateful applications on Kubernetes, you need volumes.

In this demo I show you how to use volumes in Kubernetes

Kubernetes can auto-provision volumes for you, no need to manually create an EBS volume on AWS

Now we know enough to use volumes to launch a fully working wordpress

Pet Sets enables you to run distributed applications and databases on Kubernetes, like ElasticSearch, MySQL Cluster, or Cassandra

In this demo I show you how to use StatefulSets with Cassandra

Daemon Sets will make sure a pod is running on every node

Resource Usage Monitoring using influxdb and grafana will give you application metrics

Starting from 1.11 Heapster will be deprecated. The replacement is the Metrics Server. This lecture explains the difference with heapster and how to install the Metrics Service.

This demo explains how to setup Resource Usage Monitoring using heapster + influxdb + grafana

Autoscaling can scale pods horizontally based on predefined targets

In this demo I show you how horizontal pod autoscaling (hpa) works

This lectures explains what Node and Interpod Affinity / Anti-affinity is and what the difference is between node affinity and the NodeSelector

This is a demo showing how Node Affinity works

This lecture explains taints and tolerations, which is the opposite of node affinity

This explains what Custom Resource Definitions are

This lectures gives an architecture overview of the master services

As an administrator, you can implement resource quotas to make sure one team or one person doesn't take up all resources

Namespaces can logically separate a Kubernetes cluster

In this demo I explain how to implement namespace quotas

Users can be added to your Kubernetes cluster. This lecture explains authentication and authorization

In this demo I show you how to add users using certificates

This lecture explains authorization in Kubernetes using RBAC

Every pod needs a unique IP. Not all infrastructure can easily handle this. CNI and overlay networks can help.

Sometimes you want to add / remove nodes. This is how it is done

This demo shows how to drain a Kubernetes node

Once you put a Kubernetes cluster in production, you are going to want to have full high availability. This lecture explains you how to achieve that.

This demo shows how to enable HA on your AWS Kubernetes cluster using kops

This lecture describes what admission controllers are in Kubernetes. It also explains what the admission controllers that are enabled by default do.

Introduction to the MutatingWebhook and ValidatingWebhook

This demo shows you how the MutatingWebhook works. For the webhook itself, we're using Golang.

This demo shows you how the MutatingWebhook works. For the webhook itself, we're using Golang.

This demo shows you how the MutatingWebhook works. For the webhook itself, we're using Golang.

Pod Security Policies allow you to fine-grain control pod security.

etcd is the backend of Kubernetes. This lecture explains what etcd is.

Etcd uses the raft consensus algorithm. This lecture explains how raft works.

This demo shows how to backup and restore an etcd cluster when using kops

Continuous deployment with skaffold, an open source tool by Google

A demo showing how you can develop a golang application in vscode and have every change deployed almost instantly to your  Kubernetes cluster

Lecture to give an introduction to Flux and GitOps

Demo to show how to setup flux, link it to a git repository, and deploy manifests from git to a Kubernetes cluster