S1 Hands-On Introduction to

Kubernetes

Sunday, October 29th 9:00 am–12:30 pm
at #LISA17 in SF

bit.ly/lisa17-k8s

presented by @ryanj, Developer Advocate at Red Hat

Administration

1. Introduction
   • Workshop Setup
2. Kubernetes Basics
   • Learn five K8s Primitives
3. Kubernetes Architecture
4. Local Development with Minikube
5. Wrap-up

Intro Survey / Who are you?

1. Are you doing anything with containers today?
2. Do you have any experience using Kubernetes?
3. Do you consider yourself to be basically proficient with the kubectl cli tool?
4. Can you name five basic primitives or resource types?
5. Can you name five architectural components provided by Kubernetes?

Install kubectl

Installation on linux/amd64:

curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl && chmod +x kubectl && sudo mv kubectl /usr/local/bin/

Installation on macOS:

curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/darwin/amd64/kubectl && chmod +x kubectl && sudo mv kubectl /usr/local/bin/

For other platforms, consult the official kubectl setup guide

To verify kubectl availability, try running:

kubectl help

Install minikube

Installation on linux/amd64:

curl -Lo minikube https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64 && chmod +x minikube && sudo mv minikube /usr/local/bin/

Installation on macOS:

curl -Lo minikube https://storage.googleapis.com/minikube/releases/latest/minikube-darwin-amd64 && chmod +x minikube && sudo mv minikube /usr/local/bin/

For other platforms, see the minikube release notes

Optionally, customize your cluster's memory or cpu allocation:

minikube config set memory 4096
minikube config set cpus 2

to verify minikube availability:

minikube version

Minikube Basics

minikube provides an easy way to run Kubernetes locally:

minikube start

When you are done, halt the VM to free up system resources:

minikube stop

Need a fresh start? Delete your VM instance with:

minikube delete

Minikube troubleshooting

If your minikube environment does not boot correctly:

1. Minikube requires an OS virtualization back-end
2. Most OSes include some support for virtualization
3. You can use the --vm-driver flag to select a specific virt provider

minikube start --vm-driver=virtualbox

Check the project README for more information about supported virtualization plugins

Still stuck? Consider signing up for OpenShift Starter or GKE: bit.ly/k8s-gcloud

Install docker

Download and install a binary from the docker store

Or, use a package manager to install:

brew install docker

To verify docker availability:

docker version

To reference minikube's docker daemon from your host, run:

eval $(minikube docker-env)

Install git

Install git using the instructions here:

https://git-scm.com/book/en/v2/Getting-Started-Installing-Git

To verify git availability, run:

git version

Kubernetes Command-Line Basics

with kubectl

Why Kubernetes?

Kubernetes is...

1. An open source platform for running container-based distributed solutions, featuring a modular, HA systems architecture
2. The best way to actively manage distributed solutions at scale, based on years of industry expertise (Google-scale experience)
3. An extensible distributed-solutions modeling language with a huge community following
4. A multi-vendor effort to eliminate cloud lock-in through the adoption of "cloud native" solutions (capable of runnning on any infrastructure)

Try using kubectl to list resources by type:

kubectl get nodes

Request the same info, but output the results as structured yaml:

kubectl get nodes -o yaml

Fetch an individual resource by type/id, output as json:

kubectl get node/minikube -o json

View human-readable API output:

kubectl describe node/minikube

List resources by type:

kubectl get pods

Create a new resource based on a json object specification:

curl https://raw.githubusercontent.com/ryanj/metrics-k8s/master/pod.json

kubectl create -f https://raw.githubusercontent.com/ryanj/metrics-k8s/master/pod.json

List resources by type:

kubectl get pods

Fetch a resource by type and id, output the results as yaml:

kubectl get pod metrics-k8s -o yaml

Notice any changes?

Contacting your App

Expose the pod by creating a new service (or "loadbalancer"):

kubectl expose pod/metrics-k8s --port 2015 --type=NodePort

Contact your newly-exposed pod using the associated service id:

minikube service metrics-k8s

Schedule a pod to be deleted:

kubectl delete pod metrics-k8s

Contact the related service. What happens?:

minikube service metrics-k8s

Delete the service:

kubectl delete service metrics-k8s

Create a specification for your deployment:

kubectl run metrics-k8s --image=quay.io/ryanj/metrics-k8s \
--expose --port=2015 --service-overrides='{ "spec": { "type": "NodePort" } }' \
--dry-run -o yaml > deployment.yaml

View the generated deployment spec file:

cat deployment.yaml

Bug?:You may need to edit this file, adding "---" (on it's own line) between resource 1 and resource 2 for a workaround.

Can you think of another way to fix this issue? json compatible?

Create a new resource based on your yaml specification:

kubectl create -f deployment.yaml

List resources by type:

kubectl get po,svc

Connect to your new deployment via the associated service id:

minikube service metrics-k8s

Replication

Scale up the metrics-k8s deployment to 3 replicas:

kubectl scale deploy/metrics-k8s --replicas=3

List pods:

kubectl get po

Edit deploy/metrics-k8s, setting spec.replicas to 5:

kubectl edit deploy/metrics-k8s -o json

Save and quit. What happens?

kubectl get pods

AutoRecovery

Watch for changes to pod resources:

kubectl get pods --watch

In another terminal, delete several pods by id:

kubectl delete pod $(kubectl get pods | grep ^metrics-k8s | cut -f1 -s -d' ' | head -n 3 | tr '\n' ' ')

What happend? How many pods remain?

kubectl get pods

Watch deployments (leave this running until the 'cleanup' section):

kubectl get deploy --watch

View the current state of your deployment:

minikube service metrics-k8s

Rollouts

Update your deployment's image spec to rollout a new release:

kubectl set image deploy/metrics-k8s metrics-k8s=quay.io/ryanj/metrics-k8s:v1

Reload your browser to view the state of your deployment

kubectl get rs,deploy

Rollbacks

View the list of previous rollouts:

kubectl rollout history deploy/metrics-k8s

Rollback to the previous state:

kubectl rollout undo deployment metrics-k8s

Reload your browser to view the state of your deployment

Cleanup

Cleanup old resources if you don't plan to use them:

kubectl delete service,deployment metrics-k8s

Close any remaining --watch listeners

Kubernetes Architecture

adapted for minikube

Kubernetes is designed ...

1. for managing distributed solutions at scale, based on years of industry expertise (Google-scale experience)
2. for high availabilty of the control plane and user workloads (when using pod replication), avoiding most single points of failure
3. with a modular control plane architecture, allowing many peices to be replaced without disrupting workload availability
4. to persist all of it's internal platform state within an etcd database

Local Development

with

minikube

Onboarding - Yesterday's Jam

1. git clone https://github.com/ryanj/metrics-k8s
2. cd metrics-k8s
3. npm install
4. npm start

Test - Rollout

1. Verify that your docker-env is configured for minikube
2. Run a build

   docker build . -t yourname/metrics-k8s:v1

3. Update metrics-review.yaml, setting the container image to:

   yourname/metrics-k8s:v1

4. Apply the changes locally:

   kubectl apply -f metrics-review.yaml

5. Check your latest before promoting:

   minikube service metrics-review

Resources

1. Training materials to-go: bit.ly/k8s-workshops (PDF)
2. Home: kubernetes.io
3. Docs: K8s documentation
4. Community: K8s Special Interest Groups (SIGs)
5. eBook: Kubernetes: Scheduling the Future at Cloud Scale
6. eBook: Docker Security: Using Containers Safely in Production
7. eBook: Microservices vs. Service-Oriented Architecture
8. eBook: OpenShift for Developers

Exit Survey

1. Have you ever developed using containers?
2. Do you have any experience using Kubernetes?
3. Do you consider yourself to be basically proficient with the kubectl cli tool?
4. Can you name five basic primitives or resource types?
5. Can you name five pieces of k8s architecture?
6. Are you prepared to onboard a new web dev?

Congratulations!

on completing the

[S1] Hands-on Intro to Kubernetes

tutorial at #LISA17 in SF

Please remember to complete your tutorial evaluation!