Local Kubernetes Cluster Setup With minikube

Overview

Having the capability to deploy applications in a local Kubernetes environment allows engineers to quickly develop, test, and demo without the operational overhead of a full-blown cluster. This is precisely what minikube is designed for by creating a single-node cluster within a virtual machine.

This guide will show you how to install and configure minikube and then install FusionAuth, including the required PostgreSQL database and Elasticsearch, on your minikube cluster.

Figure 1 shows an example of the minikube configuration that you will create. The cluster will consist of three Replica Sets, one for each deployment of Elasticsearch, Postgresql, and FusionAuth. Each will have one Pod, with the exception of Elasticsearch which will have three. You could scale it down to one pod, but for simplicity, you will use the default settings for the Elasticsearch chart. Each deployment exposes a Service which exposes each application as a network service. Finally, you will use an Ingress Controller of type Load Balancer that allows external traffic, or in this case, traffic from localhost to the cluster.

Requirements

Before you begin, you will need to have the following installed.

• Docker Desktop - The virtual machine environment you will use to run minikube.

• helm - Package manager used for installing and managing Kubernetes applications. In this guide, you will be using a Helm chart to install FusionAuth, a Postgresql database, and Elasticsearch cluster. For more information, see Installing Helm.

• kubectl - Command line tool that interacts with the Kubernetes API server and is useful for managing Kubernetes clusters. Before proceeding, follow the installation documentation that corresponds to your platform found here.

Install minikube

Navigate to minikube start and complete step one by selecting the options that apply to your local machine.

For example, if you are running on macOS with x86-64 architecture, Homebrew is a popular installer type:

brew install minikube

minikube start --cpus 4 --memory 5g

minikube status

minikube
type: Control Plane
host: Running
kubelet: Running
apiserver: Running
kubeconfig: Configured

kubectl get pods -A

NAMESPACE     NAME                               READY   STATUS    RESTARTS       AGE
kube-system   coredns-78fcd69978-tr4jt           1/1     Running   0              9m38s
kube-system   etcd-minikube                      1/1     Running   0              9m53s
kube-system   kube-apiserver-minikube            1/1     Running   0              9m51s
kube-system   kube-controller-manager-minikube   1/1     Running   0              9m54s
kube-system   kube-proxy-2h8b2                   1/1     Running   0              9m38s
kube-system   kube-scheduler-minikube            1/1     Running   0              9m51s
kube-system   storage-provisioner                1/1     Running   1 (9m8s ago)   9m50s

Deploy Postgresql

Start by adding the bitnami helm repository that contains the Postgresql chart:

helm repo add bitnami https://charts.bitnami.com/bitnami

To list all of the Helm repositories that you have added, execute this command:

helm repo list

The resulting output will display the chart you just added and any other helm charts that you may have added previously.

NAME      	URL
bitnami   	https://charts.bitnami.com/bitnami

Install the chart using the helm command. Set the postgresqlPassword value using the set flag for the postgres user. In this example, the release field is set to pg-minikube:

helm install pg-minikube bitnami/postgresql \
  --set postgresqlPassword=<your-postgresql-password>

When completed successfully, the output will contain some useful information about your deployment:

** Please be patient while the chart is being deployed **

PostgreSQL can be accessed via port 5432 on the following DNS names from within your cluster:

    pg-minikube-postgresql.default.svc.cluster.local - Read/Write connection

To get the password for "postgres" run:

    export POSTGRES_PASSWORD=$(kubectl get secret --namespace default pg-minikube-postgresql -o jsonpath="{.data.postgresql-password}" | base64 --decode)

To connect to your database run the following command:

    kubectl run pg-minikube-postgresql-client --rm --tty -i --restart='Never' --namespace default --image docker.io/bitnami/postgresql:11.13.0-debian-10-r40 --env="PGPASSWORD=$POSTGRES_PASSWORD" --command -- psql --host pg-minikube-postgresql -U postgres -d postgres -p 5432

To connect to your database from outside the cluster execute the following commands:

    kubectl port-forward --namespace default svc/pg-minikube-postgresql 5432:5432 &
    PGPASSWORD="$POSTGRES_PASSWORD" psql --host 127.0.0.1 -U postgres -d postgres -p 5432

When you deploy FusionAuth, you will need to use the DNS name pg-minikube-postgresql.default.svc.cluster.local as seen above and the password that you set in the install command.

You can test your deployment by attempting to connect to the database following the instructions in the output. You can also verify the pg-minikube-postgresql pod by again retrieving pods with kubectl. The following command requests pods in the default namespace with output (-o) containing additional information such as IP Address:

kubectl get pods -n default -o wide

The resulting output will show 1/1 pg-minikube-postgresql pod in a READY state:

NAME                       READY   STATUS    RESTARTS   AGE     IP           NODE       NOMINATED NODE   READINESS GATES
pg-minikube-postgresql-0   1/1     Running   0          8m33s   172.17.0.3   minikube   <none>           <none>

When a Pod is in a status of READY, it means that it is available to serve requests and should be added to load balancing pools of all matching services. You can read more about Pod lifecycles here.

You can also retrieve active services on the cluster. A Kubernetes Service exposes applications running on a pod as a network service. The following command will display the new service exposing the Postgresql application with an IP address running on port 5432:

kubectl get services -n default

NAME                              TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
kubernetes                        ClusterIP   10.96.0.1        <none>        443/TCP    82m
pg-minikube-postgresql            ClusterIP   10.108.174.128   <none>        5432/TCP   27m
pg-minikube-postgresql-headless   ClusterIP   None             <none>        5432/TCP   27m

In addition to the pg-minikube-postgresql service, you will see another service with the name kubernetes. This service is responsible for directing traffic to the Kubernetes API server.

Deploy Elasticsearch

Start by adding the Elasticsearch Helm Chart repository by running this command:

helm repo add elastic https://helm.elastic.co

You will now have the two charts that you have added in this guide in addition to any other charts you have added if you have used Helm prior to this guide.

helm repo list

NAME      	URL
bitnami   	https://charts.bitnami.com/bitnami
elastic   	https://helm.elastic.co

Before installing, you will need to download a copy of a recommended configuration for minikube virtual machines:

curl -O https://raw.githubusercontent.com/elastic/Helm-charts/master/elasticsearch/examples/minikube/values.yaml

The contents of this configuration uses a smaller JVM heap, smaller memory per pods requests, and smaller persistent volumes. The values.yaml file you downloaded should look like this:

# Permit co-located instances for solitary minikube virtual machines.
antiAffinity: "soft"

# Shrink default JVM heap.
esJavaOpts: "-Xmx128m -Xms128m"

# Allocate smaller chunks of memory per pod.
resources:
  requests:
    cpu: "100m"
    memory: "512M"
  limits:
    cpu: "1000m"
    memory: "512M"

# Request smaller persistent volumes.
volumeClaimTemplate:
  accessModes: [ "ReadWriteOnce" ]
  storageClassName: "standard"
  resources:
    requests:
      storage: 100M

Now install the Elasticsearch chart using this values.yaml configuration by including the -f flag:

helm install es-minikube elastic/elasticsearch -f values.yaml

Be aware, it may take a minute or two for the pods to reach a READY state.

Confirm your deployment by retrieving active pods in the cluster.

kubectl get pods -n default -o wide

The resulting output will show three pods for each elasticsearch node:

NAME                         READY   STATUS    RESTARTS   AGE     IP           NODE       NOMINATED NODE   READINESS GATES
elasticsearch-master-0       1/1     Running   0          7m17s   172.17.0.5   minikube   <none>           <none>
elasticsearch-master-1       1/1     Running   0          7m17s   172.17.0.4   minikube   <none>           <none>
elasticsearch-master-2       1/1     Running   0          7m17s   172.17.0.6   minikube   <none>           <none>
pg-minikube-postgresql-0     1/1     Running   0          39m     172.17.0.3   minikube   <none>           <none>

Running the kubectl command to get service information again will show that the installed Elasticsearch chart exposes the elasticsearch-master Service running at a dedicated IP address on port 9200:

kubectl get services -n default

NAME                              TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)             AGE
elasticsearch-master              ClusterIP   10.107.78.6      <none>        9200/TCP,9300/TCP   3m38s
elasticsearch-master-headless     ClusterIP   None             <none>        9200/TCP,9300/TCP   3m38s
kubernetes                        ClusterIP   10.96.0.1        <none>        443/TCP             98m
pg-minikube-postgresql            ClusterIP   10.100.117.198   <none>        5432/TCP            92m
pg-minikube-postgresql-headless   ClusterIP   None             <none>        5432/TCP            92m

Next Steps

You now are running all the necessary infrastructure to deploy a containerized application to minikube.

Next up, Deploy FusionAuth in Kubernetes.