This guide will show you how to install a Kubernetes cluster on a single machine in order to later, deploy an Apache Cassandra™ database. It be composed of one master and multiple workers.
IMPORTANT If you are using our cloud test instance (like wks78879.k8s-workshop.datastaxtraining.com), please start with the Step 7!
Docker is an open-source project that automates the deployment of software applications inside containers by providing an additional layer of abstraction and automation of OS-level virtualization on Linux.
: To install on windows please use the following installer Docker Dekstop for Windows Installer
: To install on MAC OS use Docker Dekstop for MAC Installer or homebrew with following commands:
# Fetch latest version of homebrew and formula.
brew update
# Tap the Caskroom/Cask repository from Github using HTTPS.
brew tap caskroom/cask
# Searches all known Casks for a partial or exact match.
brew search docker
# Displays information about the given Cask
brew cask info docker
# Install the given cask.
brew cask install docker
# Remove any older versions from the cellar.
brew cleanup
# Validate installation
docker -v
: To install on linux (centOS) you can use the following commands
# Remove if already install
sudo yum remove docker \
docker-client \
docker-client-latest \
docker-common \
docker-latest \
docker-latest-logrotate \
docker-logrotate \
docker-engine
# Utils
sudo yum install -y yum-utils
# Add docker-ce repo
sudo dnf config-manager --add-repo=https://download.docker.com/linux/centos/docker-ce.repo
# Install
sudo dnf -y install docker-ce --nobest
# Enable service
sudo systemctl enable --now docker
# Get Status
systemctl status docker
# Logout....Lougin
exit
# Create user
sudo usermod -aG docker $USER
newgrp docker
# Validation
docker images
docker run hello-world
docker -vDocker Compose is a tool for defining and running multi-container Docker applications. It uses YAML files to configure the application's services and performs the creation and start-up process of all the containers with a single command. The docker-compose CLI utility allows users to run commands on multiple containers at once, for example, building images, scaling containers, running containers that were stopped, and more. Please refer to Reference Documentation if you have for more detailed instructions.
: Already included in the previous package Docker for Windows
: Already included in the previous package Docker for Mac
: To install on linux (centOS) you can use the following commands
# Download deliverable and move to target location
sudo curl -L "https://github.com/docker/compose/releases/download/1.23.2/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
# Allow execution
sudo chmod +x /usr/local/bin/docker-composeThe Kubernetes command-line tool, kubectl, allows you to run commands against Kubernetes clusters. You can use kubectl to deploy applications, inspect and manage cluster resources, and view logs. Please refer to Reference Documentation for more detailed instructions.
: To install on windows please use the following installer Kubectl for Windows
: To install on MAC OS please use the following homebrew commands:
brew install kubectl To install on linux (centOS) you can use the following commands.
If the binary not working for your linux distribution you have more download urls in the KUBETCTL DOCUMENTATION.
# Download binary and move to /bin
curl -LO "https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl"
# Make the file executable
chmod +x ./kubectl
# Move the binary in to your PATH.
sudo mv ./kubectl /usr/local/bin/kubectl
#Test to ensure the version you installed is up-to-date:
kubectl version --clientDuring the workshop some bootstrap can last for a few minutes and the utilty watch can come to he rescue to avoid typing the same command multiple times to see the evolutions.
: The utility does not exist on windows but this is quite easy to create your own watch.bat file containing :
@ECHO OFF
:loop
cls
%*
timeout /t 5 > NUL
goto loop : To install on MAC OS please use the following homebrew commands:
brew install watch the utility is already installed in centOS
echo "Linux Rocks"kind (kind)cis a tool for running local Kubernetes clusters using Docker container “nodes”. kind was primarily designed for testing Kubernetes itself, but may be used for local development or CI. Please refer to Reference Documentation for more detailed instructions.
: To install on windows please dowmload the executable and place it on the PATH. You can also use Chocolatey very clever package manager for windows.
choco install kind : To install on MAC OS please use the following homebrew commands:
brew install kind To install on linux (centOS) you can use the following commands
curl -Lo ./kind https://github.com/kubernetes-sigs/kind/releases/download/v0.7.0/kind-$(uname)-amd64
chmod +x ./kind
sudo mv ./kind /usr/local/bin/kindCheck that the installation is successful. Starting for now all command will be the same on each platform, as a such we will keep providing a single command. We will mark with a blue book the command (📘) and a green book (📗) to show expected result.
📘 Command to execute
# Check existing Kind clusters
kind get clusters📗 Expected output
No kind clusters found.During this workshop we will work with a cluster with multiple Cassandra nodes. As of now the Cassandra Operator needs a worker per node. We will create a Kubernetes cluster based on the following configuration 1 master, 5 workers to be able to spawn some multi nodes clusters. This is also the reason why kind has been preferred as minikube another solution to run Kubernetes locally but handling only a managin a single worker.
📘 6a. Execute the following command to create a kubernetes cluster
kind create cluster --name kind-cassandra --config ./0-setup-your-cluster/01-kind-config.yaml📗 Expected output
Creating cluster "kind-cassandra" ...
✓ Ensuring node image (kindest/node:v1.17.0) 🖼
✓ Preparing nodes 📦 📦 📦 📦
✓ Writing configuration 📜
✓ Starting control-plane 🕹️
✓ Installing CNI 🔌
✓ Installing StorageClass 💾
✓ Joining worker nodes 🚜
Set kubectl context to "kind-kind-cassandra"
You can now use your cluster with:
kubectl cluster-info --context kind-kind-cassandra
Have a question, bug, or feature request? Let us know! https://kind.sigs.k8s.io/#community 🙂
📘 6b. Execute the following command to visualize the list of your clusters
# Show the new created cluster
kind get clusters📗 Expected output
kind-cassandra
📘 6c. Execute the following command to link kubectl with our new cluster
kubectl cluster-info --context kind-kind-cassandra📗 Expected output
Kubernetes master is running at https://127.0.0.1:45451
KubeDNS is running at https://127.0.0.1:45451/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
📘 6d. Execute the following command to list nodes in k8s cluster
kubectl get nodes📗 Expected output
NAME STATUS ROLES AGE VERSION
kind-cassandra-control-plane Ready master 2m4s v1.17.0
kind-cassandra-worker Ready <none> 86s v1.17.0
kind-cassandra-worker2 Ready <none> 88s v1.17.0
kind-cassandra-worker3 Ready <none> 88s v1.17.0
kind-cassandra-worker4 Ready <none> 88s v1.17.0
kind-cassandra-worker5 Ready <none> 88s v1.17.0
Cass-operator is built to watch over pods running Casandra or DSE in a Kubernetes namespace. We need to create a namespace for the cluster. For the rest of this guide, we will be using the namespace cass-operator. You can pick any name you like but you would have to change the commands accordingly.
📘 7a. Execute the following command to create the namespace
kubectl create ns cass-operator📗 Expected output
namespace/cass-operator created
Kubernetes uses the StorageClass resource as an abstraction layer between pods needing persistent storage and the storage resources that a specific Kubernetes cluster can provide. We recommend using the fastest type of networked storage available. Let's create one for your environment.
📘 7b. Execute the following command to list existing storageClass
kubectl get storageclass📗 Expected output
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
standard (default) rancher.io/local-path Delete WaitForFirstConsumer false 11m📘 7c. Execute the following command describe default storageClass
kubectl describe storageclass standard📗 Expected output (may vary)
Name: standard
IsDefaultClass: Yes
Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"storage.k8s.io/v1","kind":"StorageClass","metadata":{"annotations":{"storageclass.kubernetes.io/is-default-class":"true"},"name":"standard"},"provisioner":"rancher.io/local-path","reclaimPolicy":"Delete","volumeBindingMode":"WaitForFirstConsumer"}
,storageclass.kubernetes.io/is-default-class=true
Provisioner: rancher.io/local-path
Parameters: <none>
AllowVolumeExpansion: <unset>
MountOptions: <none>
ReclaimPolicy: Delete
VolumeBindingMode: WaitForFirstConsumer
Events: <none>
We are are interested in a few fields to intialize the yaml to create a storageClass. You can find more information in the Reference Documentation and the dedicated page to edit those.
One thing thing to note here is volumeBindingMode: WaitForFirstConsumer. The default value is Immediate and should not be used. It can prevent Cassandra pods from being scheduled on a worker node. If a pod fails to run and its status reports a message like, had volume node affinity conflict, then check the volumeBindingMode of the StorageClass being used
This file should be adapted tor reflect your Kubernetes environment. We have several samples in the repository for kind, Minikube and GKE.
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
annotations:
storageclass.kubernetes.io/is-default-class: "true"
name: server-storage
provisioner: rancher.io/local-path
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer📘 7d. Execute the following command to create a new storageClass named server-storage
For the rest of this guide, we would assume you have defined a StorageClass and named it server-storage.
kubectl -n cass-operator apply -f ./0-setup-your-cluster/02-storageclass-kind.yaml📘 7e. Execute the following command to list the storageClass
kubectl -n cass-operator get storageClass
📗 Expected output
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
server-storage (default) rancher.io/local-path Delete WaitForFirstConsumer false 25m
standard (default) rancher.io/local-path Delete WaitForFirstConsumer false 88m
