Intro to Cassandra On Kubernetes

Learning Workshop

In this session we will be taking a look at running a distributed system on top of another distributed system while using persistant storage to make sure our data stays in tact.

Before starting

Workshop attendees will receave an email with the instance info prior to the workshop.

Notice that training cloud instances will be available only during the workshop and will be terminated 24 hours later. If you are in our workshop we recommend using the provided cloud instance, you can relax as we have you covered: prerequisites are installed already.

⚡ IMPORTANT NOTE: Everywhere in this repo you see <YOURADDRESS> replace with the URL for the instance you were given.

Table of content

Title	Description
1 - Getting Connected	Instructions
2 - Setting Up Storage	Instructions
3 - Setting Up Cassandra	Instructions
4 - Connecting To Cassandra	Instructions
5 - Resources	Instructions

1. Getting Connected

✅ Step 1a: The first step in the section.

In your browser window, navigate to the url :3000 where your address is the one emailed to you before the session.

When you arrive at the webpage you should be greeted by something similar to this.

Click in the Terminal menu from the top of the page and select new terminal as shown below

Once you have opened the terminal run

kubectl get nodes

📃output

NAME                        STATUS   ROLES    AGE   VERSION
learning-cluster-master     Ready    master   49m   v1.19.4
learning-cluster-worker-0   Ready    <none>   49m   v1.19.4
learning-cluster-worker-1   Ready    <none>   49m   v1.19.4
ubuntu@learning-cluster-master:~/workshop$

If you see the above output you are ready for the lab.

2. Setting Up Storage

✅ Step 2a: Setting Up Block Devices.

kubectl get pods --all-namespaces

wget https://openebs.github.io/charts/openebs-operator.yaml
kubectl apply -f openebs-operator.yaml
kubectl get pods --all-namespaces

kubectl get blockdevice -n openebs
kubectl label bd -n openebs BLOCKDEVICENAMEHERE openebs.io/block-device-tag=learning
kubectl label bd -n openebs BLOCKDEVICENAMEHERE openebs.io/block-device-tag=learning

kubectl apply -f local-device-sc.yaml
kubectl get sc local-device

✅ Step 2b: Verify Config

kubectl get sc local-device

3. Setting Up Cassandra

✅ Step 3a: Install Helm

curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3
chmod 700 get_helm.sh
./get_helm.sh

✅ Step 3b: Add the K8ssandra repo

helm repo add k8ssandra https://helm.k8ssandra.io/stable
helm repo update

✅ Step 3c: Setup the Ingress

helm repo add traefik https://helm.traefik.io/traefik
helm repo update
helm install traefik traefik/traefik -f traefik.yaml

✅ Step 3d: configure the k8ssandra.yaml Open the file in the browser and add in your IP address where it says

✅ Step 3e: Install the Cassandra Cluster

helm install -f k8ssandra.yaml k8ssandra k8ssandra/k8ssandra

kubectl get cassandradatacenters

kubectl describe CassandraDataCenter dc1

4. Connecting To Cassandra

✅ Step 4a: Retreave the Cluster username

kubectl get secret k8ssandra-superuser -o jsonpath="{.data.username}" | base64 --decode

✅ Step 4b: Retreave the Cluster password

kubectl get secret k8ssandra-superuser -o jsonpath="{.data.password}" | base64 --decode

✅ Step 4c: Install the Cassandra driver

sudo pip3 install cassandra-driver

✅ Step 4d: Testing our database

kubectl exec --stdin --tty k8ssandra-dc1-default-sts-0 -- /bin/bash
cqlsh -u YOURUSERNAME -p YOURPASSWORD

✅ Step 4e: Insert Data

CREATE KEYSPACE test WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', 'dc1' : 3 };
CREATE TABLE test.users (username text, name text, age int, PRIMARY KEY(username));
INSERT INTO test.users(username,name,age) VALUES ('EricZ','Eric Zietlow',67);

5. Resources

For further reading go to the OpenEBS Docs Check out our new Discord server Invite Get into more with the Data On Kubernetes Community DOKc For the K8ssandra Project k8ssandra.io Many more workshops to come so Please subscribe to the YouTube Channel to be notified.

muratkars/IntroToCassOnK8