1.10

The DC/OS + Kubernetes + Helm - cool beer demo

Are you wondering how Java, Spring Boot, MySQL, Neo4j, Apache Zeppelin, Apache Spark, Elasticsearch, Apache Mesos, DC/OS, Kubernetes and Helm can all fit in one demo? Well, we'll show you! This is a cool demo, so grab your favourite beer and enjoy. 🍺

Note: It is based on beer-demo, but beer-service is running on Kubernetes and is exposed to Internet with Cloudflare Warp.

So that means all the backend is running on DC/OS and Internet facing services are running on Kubernetes.

DC/OS cluster with Kubernetes

Note: In order to deploy all parts of this demo successfully, I would recommend to spin up a cluster with at least 7 private DC/OS nodes, also you will need Kubernetes package to be installed (Instruction are provided below).

If you do not have DC/OS cluster you can easily bootstrap it as per dcos-kubernetes-quickstart. By default install is set to 3 private DC/OS nodes, you need to set it to 7.

Installing DC/OS CLI

The recommended method to install the DC/OS CLI is from the DC/OS web interface. Or, you can manually install the CLI by using the instructions below.

Installing the DC/OS CLI on Linux

Installing the DC/OS CLI on macOS

Connecting to DC/OS cluster

Connect to your DC/OS cluster:

dcos cluster setup <http://REPLACE_WITH_YOUR_MASTER_IP>

Check that cluster in the list:

dcos cluster list
        NAME                       CLUSTER ID               VERSION           URL
blabla-vad0b3*                      11-333-44-55            1.10.2            http://1.2.3.4

Installing Kubernetes (if you have't done it already)

To install Kubernetes on DC/OS is easy as:

dcos package install --yes beta-kubernetes

Wait till it gets installed, you can check it's progress in DC/OS Dashboard/Services/kubernetes.

Installing kubectl

Use the Kubernetes command-line tool, kubectl, to deploy and manage applications on Kubernetes. Using kubectl, you can inspect cluster resources; create, delete, and update components; and look at your new cluster and bring up example apps.

Follow instructions here to download and install.

Connecting to Kubernetes API

In order to access the Kubernetes API from outside the DC/OS cluster, one needs SSH access to a node-agent. On a terminal window, run:

ssh -4 -N -L 9000:apiserver-insecure.kubernetes.l4lb.thisdcos.directory:9000 <REPLACE_WITH_YOUR_REMOTE_LINUX_USERNAME>@<http://REPLACE_WITH_YOUR_MASTER_IP>

When the Kubernetes API task(s) are healthy, it should be accessible on http://localhost:9000.

We are now ready to install and configure kubectl, the Kubernetes CLI tool. For the sake of simplicity, we'll be covering the set-up alone:

kubectl config set-cluster dcos-k8s --server=http://localhost:9000
kubectl config set-context dcos-k8s --cluster=dcos-k8s --namespace=default
kubectl config use-context dcos-k8s

Test access by retrieving the Kubernetes cluster nodes:

$ kubectl get nodes
NAME                                   STATUS    AGE       VERSION
kube-node-0-kubelet.kubernetes.mesos   Ready     7m        v1.9.0
kube-node-1-kubelet.kubernetes.mesos   Ready     7m        v1.9.0
kube-node-2-kubelet.kubernetes.mesos   Ready     7m        v1.9.0

Helm setup

To deploy beer-service we will need Helm.

To download and install Helm cli run:

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

Then we need to install Helm's server side Tiller:

helm init

Once Tiller is installed, running helm version should show you both the client and server version:

helm version
Client: &version.Version{SemVer:"v2.8.0", GitCommit:"14af25f1de6832228539259b821949d20069a222", GitTreeState:"clean"}
Server: &version.Version{SemVer:"v2.8.0", GitCommit:"14af25f1de6832228539259b821949d20069a222", GitTreeState:"clean"}

Now we need to add DC/OS Labs Helm Charts repo (where this demo Helm charts are published) to Helm:

helm repo add dlc https://dcos-labs.github.io/charts/
helm repo update

Deploy Backend on DC/OS

Let's deploy Backend using the dcos cli:

dcos marathon group add https://raw.githubusercontent.com/dcos/demos/master/dcos-k8s-beer-demo/1.10/marathon-apps/marathon-configuration.json

Wait till it gets installed, you can check it's progress in DC/OS Dashboard/Services/beer.

Deploy Frontend App on Kubernetes and expose it locally

Frontend App

To deploy Frontend App chart run:

helm install --name beer --namespace beer dlc/beer-service-web

Check that pods are running:

kubectl -n beer get pods
NAME                                                    READY     STATUS    RESTARTS   AGE
beer-beer-service-web-1676235277-s9ptv                  1/1       Running   0          2m
beer-beer-service-web-1676235277-tskrp                  1/1       Running   0          2m

Accessing Frontend App locally

To access app locally run:

kubectl port-forward -n beer beer-beer-service-web-1676235277-tskrp 8080

Now you should be able to check beer at http://127.0.0.1:8080

Deploy Frontend App and expose it via Cloudflare Warp on Kubernetes

Frontend App

To deploy Frontend App chart (do not forget to replace there with your domain_name) run:

helm upgrade --install beer --namespace beer dlc/beer-service-web \
  --set ingress.enabled="true",ingress.host="beer.mydomain.com"

Check that pods are running:

kubectl -n beer get pods
NAME                                                    READY     STATUS    RESTARTS   AGE
beer-beer-service-web-854fb8dc65-76bk4                  2/2       Running   0          2m
beer-beer-service-web-854fb8dc65-d8tm9                  2/2       Running   0          2m

Cloudflare Warp

The Cloudflare Warp Ingress Controller makes connections between a Kubernetes service and the Cloudflare edge, exposing an application in your cluster to the internet at a hostname of your choice. A quick description of the details can be found at https://warp.cloudflare.com/quickstart/.

Note: Before installing Cloudflare Warp you need to obtain Cloudflare credentials for your domain zone. The credentials are obtained by logging in to https://www.cloudflare.com/a/warp, selecting the zone where you will be publishing your services, and saving the file locally to dcos-k8s-beer-demo folder.

To deploy Cloudflare Warp Ingress Controller chart run:

helm install --name beer-ingress --namespace beer dlc/cloudflare-warp-ingress --set cert=$(cat cloudflare-warp.pem | base64)

Check that pods are running:

kubectl -n beer get pods
NAME                                                    READY     STATUS    RESTARTS   AGE
beer-beer-service-web-57f9bc955c-c9v4q                  2/2       Running   0          3m
beer-beer-service-web-57f9bc955c-k4mps                  2/2       Running   0          3m
beer-ingress-cloudflare-warp-ingress-775b5965fd-qd4rk   1/1       Running   0          16s

Testing external access

Now you should be able to check beer at https://beer.mydomain.com/ And if you noticed Cloudflare Warp creates https connection by default :-)

Conclusion

Cheers 🍺