JupyterHub on Kubernetes

Important: Magnum is currently in technical preview on STFC Cloud. If you have any feedback or suggestions please send it to cloud-support@gridpp.rl.ac.uk

This documentation assumes that you will be installing JupyterHub on a Kubernetes cluster that has been created using OpenStack Magnum.

In this tutorial we will break the installation down into the following:
  • Create a cluster template and launch a Kubernetes cluster using OpenStack Magnum
  • Install Helm v3 and define persistent volume for the cluster
  • Install JupyterHub

Creating a Kubernetes Cluster

The template for the cluster:

openstack coe cluster template create --coe kubernetes \
                                      --image cf37f7d0-1d6b-4aab-a23b-df58542c59cb \
                                      --external-network External \
                                      --network-driver flannel \
                                      --volume-driver cinder \
                                      --dns-nameserver 8.8.8.8 \
                                      --flavor c1.medium \
                                      --master-flavor c1.medium \
                                      --docker-volume-size 10 \
                                      --docker-storage-driver devicemapper \
                                      --labels kube_tag=v1.14.3,kube_dashboard_enabled=1,heat_container_agent_tag=train-stable-3,auto_healing=true,ingress_controller=traefik
                                      --server_type vm
                                      test-template

Create a cluster:

openstack coe cluster create --cluster-template test-template \
                             --keypair mykeypair \
                             --docker-volume-size 10  \
                             --master-count 1 \
                             --node-count 1 \
                             test-cluster

  #This should return an output similar to this one
  Request to create cluster 27cdcad8-375f-4d4f-a186-8fa99b80c5c5 accepted
  #This indicates that the command was successful and the cluster is being built

Once the cluster has been created successfully, we can associate a floating IP to the master node VM and then SSH into the cluster:

ssh -i mykeypair.key fedroa@FLOATING_IP

#This should return something similar to:

Last login: Fri Sep 18 13:17:02 2020 from 130.XXX.XXX.XXX

[fedora@test-template-vbo5u2doyiao-master-0 ~]$

#You have now successfully connected to the master node

Configure Storage

Magnum does not automatically configure cinder storage for clusters.

The storage class can be defined using a YAML file. For example we could define the storage class to be:

YAML File from: https://github.com/zonca/jupyterhub-deploy-kubernetes-jetstream/blob/master/kubernetes_magnum/storageclass.yaml_

apiVersion: storage.k8s.io/v1

kind: StorageClass

metadata:

  name: standard

  annotations:

    storageclass.beta.kubernetes.io/is-default-class: "true"

  labels:

    kubernetes.io/cluster-service: "true"

    addonmanager.kubernetes.io/mode: EnsureExists

provisioner: kubernetes.io/cinder

Then we create the storage class:

kubectl create -f storageclass.yaml

Helm v3

The Train release supports Helm v2 charts being installed and supports labels for installing Tiller.

However, it is possible to install and run charts for Helm v3.

In the Ussuri release onwards, Magnum supports the use of a label to install Helm v3 client. This label can be added to a template or at cluster creation time.

Note: Helm v2 reaches end of support in November 2020

To install Helm 3:

curl https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | bash

Other methods for installing Helm v3 can be found here: https://helm.sh/docs/intro/install/

Now Helm v3 has been installed, we can install JupyterHub.

JupyterHub

The following is the tutorial from the _Zero to JupyterHub with Kubernetes_ installation documentation.

# Generate a random hex string
openssl rand -hex 32  #copy the output

Then create a file called config.yaml and write the following:

vi config.yaml # fedora doesn't use nano
proxy:
  secretToken: "<RANDOM_HEX>" #this is the random string which you have copied

Next is to add the JupyterHub Helm chart to your chart repository and install it.

helm repo add jupyterhub https://jupyterhub.github.io/helm-chart/
helm repo update

RELEASE=jhub
NAMESPACE=jhub

helm upgrade --cleanup-on-fail \
  --install $RELEASE jupyterhub/jupyterhub \
  --namespace $NAMESPACE \
  --create-namespace \
  --version=0.9.0 \
  --values config.yaml \
  --timeout 30m0s #This is to stop the installation from timing out

When installation is complete it should return a message similar to the following:

NAME: jhub
LAST DEPLOYED: Tue Oct 13 11:01:15 2020
NAMESPACE: jhub
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
Thank you for installing JupyterHub!

Your release is named jhub and installed into the namespace jhub.

You can find if the hub and proxy is ready by doing:

 kubectl --namespace=jhub get pod

and watching for both those pods to be in status 'Running'.

You can find the public IP of the JupyterHub by doing:

 kubectl --namespace=jhub get svc proxy-public

It might take a few minutes for it to appear!

Note that this is still an alpha release! If you have questions, feel free to
  1. Read the guide at https://z2jh.jupyter.org
  2. Chat with us at https://gitter.im/jupyterhub/jupyterhub
  3. File issues at https://github.com/jupyterhub/zero-to-jupyterhub-k8s/issues