How to run a Webserver on Standalone Deployments

This guide is does not come with support by Element. It is not part of the Element Server Suite (ESS) product. Use at your own risk. Remember you are responsible of maintaining this software stack yourself.

Some config options require a web content to be served. For example :

One way to provide this content is to run a web server in the same Kubernetes Cluster as the Element Enterprise Suite.

Please consider other options before installing and maintaining just another webserver for this.

Consider to use an existing web server 1st.

The following guide describes the steps to setup the Bitnami Apache helm chart in the Standalone Microk8s cluster setup by Element Server Suite..

You need:
You get:

You can deploy a Webserver to the same Kubernetes cluster that Element Server Suite is using. This guide is applicable to the Single Node deployment of Element Server Suite but can be used for guidance on how to host a webserver in other Kubernetes Clusters as well.

You can use any webserver that you like, in this example we will user the Bitnami Apache chart.

We need helm version 3. You can follow this Guide or ask microk8s to install helm3.

Enabling Helm3 with microk8s

$ microk8s enable helm3
Infer repository core for addon helm3
Enabling Helm 3
Fetching helm version v3.8.0.
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 12.9M  100 12.9M    0     0  17.4M      0 --:--:-- --:--:-- --:--:-- 17.4M
Helm 3 is enabled

Let's check if it is working

$ microk8s.helm3 version
version.BuildInfo{Version:"v3.8.0", GitCommit:"d14138609b01886f544b2025f5000351c9eb092e", GitTreeState:"clean", GoVersion:"go1.17.5"}

Create and Alias for helm

echo alias helm=microk8s.helm3 >> ~/.bashrc
source ~/.bashrc

Enable the Bitnami Helm Chart repository

Add the bitnami repository

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

Update the repo information

helm repo update

Prepare the Web-Server Content

Create a directory to supply content :

sudo mkdir /var/www/apache-content

Put your content e.g. a homepage into the apache-content directory.

cp /tmp/background.jpg /apache-content/
cp /tmp/home.html ~element/apache-content/

There are multiple ways to provide this content to the apache pod. The bitnami helm chart user ConfigMaps, Physical Volumes or a Git Repository.

ConfigMaps are a good choice for smaller amounts of data. There is a hard limit of 1MiB on ConfigMaps. So if all your data is not more that 1MiB, the config map is a good choice for you.

Physical Volumes are a good choice for larger amounts of data. There are several choices for backing storage available. In the context of the standalone deployments of ESS a Physical Hostpath is the most practical. HostPath is not a good solution for mutli node k8s clusters, unless you pin a pod to a certain node. Pinning the pod to a single node would put the workload at risk, should that node go down.

Git Repository is a favourite as it versions the content and you track and revert to earlier states easily. The bitnami apache helm chart is built in a way that updates in regular intervals to your latest changes.

We are selecting the Physical Volume option to serve content in this case. Our instance of Microk8s comes with the Hostpath storage addon enabled.

Define the physical volume:

cat <<EOF>pv-volume.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: apache-content-pv
  labels:
    type: local
spec:
  storageClassName: microk8s-hostpath
  persistentVolumeReclaimPolicy: Retain
  capacity:
    storage: 100Mi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/var/www/apache-content"
EOF

Apply to the cluster

kubectl apply -f pv-volume.yaml

Next we need a Physical Volume Claim:

cat <<EOF>pv-claim.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: apache-content-pvc
spec:
  volumeName: apache-content-pv
  storageClassName: microk8s-hostpath
  accessModes: [ReadWriteOnce]
  resources: { requests: { storage: 100Mi } }
EOF

Apply to the cluster to create the pvc

kubectl apply -f pv-claim.yaml

Configure the Helm Chart

We need to add configurations to adjust the apache deployment to our needs. The K8s service should be switched to ClusterIP. The Single Node deployment includes an Ingress configuration through nginx that we can use to route traffic to this webserver. The name of the ingressClass is "public". We will need to provide a hostname. This name needs to be resolvable through DNS. This could be done through the wildcard entry for *.$BASEDOMAIN that you might already have. You will need a certificate and certificate private key to secure this connection through TLS.

The full list of configuration options of this chart is explained in the bitnami repository here

Create a file called apache-values.yml in the home directory of your element user directory.

Remember to replace BASEDOMAIN with the correct value for your deployment.

cat <<EOF>apache-values.yaml
service:
  type: ClusterIP
ingress:
  enabled: true
  ingressClassName: "public"
  hostname: pages.BASEDOMAIN
htdocsPVC: apache-content-pvc
EOF

Deploy the Apache Helm Chart

Now we are ready to deploy the apache helm chart

helm install myhomepage -f apache-values.yaml oci://registry-1.docker.io/bitnamicharts/apache

Manage the deployment

List the deployed helm charts:

$ helm list 
NAME      	NAMESPACE	REVISION	UPDATED                                	STATUS  	CHART        	APP VERSION
myhomepage	default  	1       	2023-09-06 14:46:33.352124975 +0000 UTC	deployed	apache-10.1.0	2.4.57     

Get more details:

$ helm status myhomepage
NAME: myhomepage
LAST DEPLOYED: Wed Sep  6 14:46:33 2023
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
CHART NAME: apache
CHART VERSION: 10.1.0
APP VERSION: 2.4.57

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

1. Get the Apache URL by running:

  You should be able to access your new Apache installation through:
      - http://pages.lutz-gui.sales-demos.element.io

If you need to update the deployment, modify the required apache-values.yaml and run :

helm upgrade myhomepage -f apache-values.yaml oci://registry-1.docker.io/bitnamicharts/apache

If you don't want the deployment any more, you can remove it.

helm uninstall myhomepage

Secure the deployment with certificates

If you are in a connected environment, you can rely on cert-manager to create certificates and secrets for you.

Cert-manager with letsencrypt

If you have cert-manager enabled. You will just need to add the right annotations to the ingress of your deployment. Modify you apache-values.yaml and add these lines to the ingress block :

  tls: true
  annotations: 
    cert-manager.io/cluster-issuer: letsencrypt
    kubernetes.io/ingress.class: public

You will need to upgrade your deployment to reflect these changes:

helm upgrade myhomepage -f apache-values.yaml oci://registry-1.docker.io/bitnamicharts/apache

Custom Certificates

There are situations in which you want custom certificates instead. These can be used by modifying your apache-values.yaml. Add the following lines to the ingress block in the apache-values.yaml. Take care to get the indentation right. Replace the ... with your data.

  tls: true
  extraTls:
  - hosts:
    - pages.lutz-gui.sales-demos.element.io
    secretName: "pages.lutz-gui.sales-demos.element.io-tls"
  secrets:
    - name: pages.lutz-gui.sales-demos.element.io-tls
      key: |-
        -----BEGIN RSA PRIVATE KEY-----
        ...
        -----END RSA PRIVATE KEY-----
      certificate: |-
        -----BEGIN CERTIFICATE-----
        ...
        -----END CERTIFICATE-----

You will need to upgrade your deployment to reflect these changes:

helm upgrade myhomepage -f apache-values.yaml oci://registry-1.docker.io/bitnamicharts/apache

Tips and Tricks

You can make your life easier by using bash completing and an alias for kubectl. You will need to have the bash-completion package installed as a prerequisite.

For all users on the system:

kubectl completion bash | sudo tee /etc/bash_completion.d/kubectl > /dev/null

Set an aias for kubectl for your user:

echo 'alias k=kubectl' >>~/.bashrc

Enable auto-completion for your alias

echo 'complete -o default -F __start_kubectl k' >>~/.bashrc

After reloading your Shell, you can now enjoy auto completion for your k ( kubectl ) commands.


Revision #10
Created 11 August 2023 10:24:30 by Lutz Lange
Updated 12 September 2023 06:35:10 by Lutz Lange