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Managed Cluster setup

The managed cluster setup offers a step-by-step setup for a new kubernetes cluster.

Ideally the clusters should be managed by argocd but there is still some initial setup to be done to allow the cluster to communicate with the outside world.

We assume that you already have the cluster of you choice set up. To make sure you are using a fresh cluster run: 

kubectl get namespaces

The output should look like this 

$ kubectl get namespaces
NAME              STATUS   AGE
default           Active   138d
kube-node-lease   Active   40m
kube-public       Active   138d
kube-system       Active   138d

So now we have a clean cluster its time to get started.

Nginx & Load Balancer v1.5.1​

Most clusters want to allow users to access at least certain parts of it from outside the cluster. While we can expose specific node ports outside the cluster, a load balancer makes the most sense and allows us to have more control over our routes in a central place.

Load balancers expose the cluster to the outside world in a safe and manageable way while proving a lot of additional features

While there are a few different load balancers out there we will be using the NGINX load balancer.

We will be using helm to install nginx as it is the easiest way to get it up and running.

kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.4.0/deploy/static/provider/cloud/deploy.yaml
info

If we want to increase the replica count of our ingress controller this can be done by modifying the deployment.

Increase replicas
kubectl scale --replicas=2 deployment ingress-nginx-controller -n ingress-nginx

Your ingress controller and load balancer should be set up now with all the bells and whistles

Cert Manager​

The cert manager is responsible for creating certificates for you apps and making sure that they are kept up to date.

We will be using lets encrypt for as our certification authority. We will also be using helm to deploy our cert-manager

Add helm repo and update repo

Add repo and update repo
helm repo add jetstack https://charts.jetstack.io
helm repo update
caution

If cert-manager already exists you can remove it using 

helm uninstall cert-manager --namespace cert-manager

Now let install cert manager

helm install cert-manager jetstack/cert-manager --namespace cert-manager --version v1.10.0  --create-namespace --set installCRDs=true

After setting up the cert manager we need to set up a cluster issuer. The cluster issuer is responsible for creating certificates in all namespaces

Cluster issuer
kubectl apply -f - <<EOF
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: le-clusterissuer
  namespace: cert-manager
spec:
  acme:
    server: https://acme-v02.api.letsencrypt.org/directory
    email: iot@nimbit.de
    privateKeySecretRef:
      name: le-clusterissuer
    solvers:
    - http01:
        ingress:
          class:  nginx
EOF

Redis Cluster Issuer​

Redis Cluster Issuer
kubectl apply -f - <<EOF
---
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: selfsigned-issuer
  namespace: cert-manager
spec:
  selfSigned: {}
---
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: redis-tls-ca
  namespace: cert-manager
spec:
  ca:
    secretName: redis-tls-ca-cert
EOF

TCP Config maps​

kubectl apply -f - <<EOF
apiVersion: v1
kind: ConfigMap
metadata:
  name: udp-services
  namespace: ingress-nginx
EOF

kubectl apply -f - <<EOF
apiVersion: v1
kind: ConfigMap
metadata:
  name: tcp-services
  namespace: ingress-nginx
EOF