What is MicroK8s?
MicroK8s is an amazing offering from Canonical (makers of Ubuntu). It is a lightweight Kubernetes Cluster that runs inside of a snap package. It is build to support Production workloads and can be put into an HA cluster with minimal effort.
Although it is a smaller, lightweight Kubernetes, it is quite robust and polished.
Requirements
By default, you can install this on any Ubuntu machine (18.04, 20.04, 22.04) and other distros if you install the Snap store manually. I prefer Ubuntu for this, as I have found it more stable.
Installing MicroK8s
Installing MicroK8s is easy on a fresh Ubuntu Install. For this post, I will be using Ubuntu 22.04 (latest version).
$ sudo snap install microk8s --classic --channel=1.24
microk8s (1.24/stable) v1.24.4 from Canonical✓ installedYou need to give your user permissions to interact with MicroK8s and store kube config files.
$ sudo usermod -a -G microk8s $USER
$ sudo chown -f -R $USER ~/.kubeOnce you have done that, you can check it's status with:
$ microk8s status --wait-ready
microk8s is running
high-availability: no
datastore master nodes: 127.0.0.1:19001
datastore standby nodes: none
addons:
enabled:
ha-cluster # (core) Configure high availability on the current node
disabled:
community # (core) The community addons repository
dashboard # (core) The Kubernetes dashboard
dns # (core) CoreDNS
gpu # (core) Automatic enablement of Nvidia CUDA
helm # (core) Helm 2 - the package manager for Kubernetes
helm3 # (core) Helm 3 - Kubernetes package manager
host-access # (core) Allow Pods connecting to Host services smoothly
hostpath-storage # (core) Storage class; allocates storage from host directory
ingress # (core) Ingress controller for external access
mayastor # (core) OpenEBS MayaStor
metallb # (core) Loadbalancer for your Kubernetes cluster
metrics-server # (core) K8s Metrics Server for API access to service metrics
prometheus # (core) Prometheus operator for monitoring and logging
rbac # (core) Role-Based Access Control for authorisation
registry # (core) Private image registry exposed on localhost:32000
storage # (core) Alias to hostpath-storage add-on, deprecatedYay! That is it, we have a functioning cluster!
Enabling Add Ons
Add Ons in MicroK8s do numerous things, not all of them will be needed in our case. To see the full list of Add Ons and what they do, I recommend checking out the MicroK8s Docs.
The Add Ons we're going to install are:
- dns - needed for DNS resolution inside of the cluster, each pod and service gets a DNS address inside of the cluster.
- ingress - needed to expose web applications, installs Nginx Ingress controller which will be exposed on ports 80 and 443.
- hostpath-storage - needed for storing persistent files, stores files on local disk (Node OS Disk)
Other Add Ons worth noting:
- Metallb - Virtual Load balancer that can place a virtual NIC on your network that listens for traffic, this means if you have more than 1 node, you can assign 1 ip address and it will load balance all the nodes.
- Prometheus - Monitoring and metrics within the cluster. This installs the Prometheus Operator, which can be useful if you want to deploy additional Prometheus servers
To enable, simply run:
$ microk8s enable dns ingress hostpath-storage
Infer repository core for addon dns
Infer repository core for addon ingress
Infer repository core for addon hostpath-storage
Enabling DNS
Applying manifest
serviceaccount/coredns created
configmap/coredns created
deployment.apps/coredns created
service/kube-dns created
clusterrole.rbac.authorization.k8s.io/coredns created
clusterrolebinding.rbac.authorization.k8s.io/coredns created
Restarting kubelet
DNS is enabled
Enabling Ingress
ingressclass.networking.k8s.io/public created
namespace/ingress created
serviceaccount/nginx-ingress-microk8s-serviceaccount created
clusterrole.rbac.authorization.k8s.io/nginx-ingress-microk8s-clusterrole created
role.rbac.authorization.k8s.io/nginx-ingress-microk8s-role created
clusterrolebinding.rbac.authorization.k8s.io/nginx-ingress-microk8s created
rolebinding.rbac.authorization.k8s.io/nginx-ingress-microk8s created
configmap/nginx-load-balancer-microk8s-conf created
configmap/nginx-ingress-tcp-microk8s-conf created
configmap/nginx-ingress-udp-microk8s-conf created
daemonset.apps/nginx-ingress-microk8s-controller created
Ingress is enabled
Enabling default storage class.
WARNING: Hostpath storage is not suitable for production environments.
deployment.apps/hostpath-provisioner created
storageclass.storage.k8s.io/microk8s-hostpath created
serviceaccount/microk8s-hostpath created
clusterrole.rbac.authorization.k8s.io/microk8s-hostpath created
clusterrolebinding.rbac.authorization.k8s.io/microk8s-hostpath created
Storage will be available soon.We now have a functional MicroK8s cluster! You should see some Pods running, if you run the command:
$ microk8s kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-66bcf65bb8-czms5 1/1 Running 0 2m54s
kube-system calico-node-klp4c 1/1 Running 0 25m
kube-system calico-kube-controllers-7dfd687fdb-zbdgj 1/1 Running 0 25m
kube-system hostpath-provisioner-78cb89d65b-c5xq5 1/1 Running 0 97s
ingress nginx-ingress-microk8s-controller-cbjn9 1/1 Running 0 97s
You will also see a 404 page if you visit the IP address of your server:
So this means Ingress is working as well! Wooo!
## Conclusion
We have installed MicroK8s, enabled the necessary Add Ons, and tested to make sure it was working. We are now ready for some workloads!
In the next post, I will show you how to install FreshRSS using Helm and MicroK8s.