Microk8s AddOns

DNS

DNS should always be anabled. It is the default implementation for service discovery in a kubernetes environment.
Details … More details …

MetalLb

Metallb is a substitute for a cloud loadbalancer provided by a cloud service provider. That’s the gateway from where all incoming traffic will flow into our kube. MetalLb will assign an IP from your local network to each consuming service of type LoadBalancer. You will be prompted for the portrange as commented Prerequisites 3) 192.168.1.200 - 192.168.1.201
More details …

Helm(3) charts

Helm charts are a convenient way to install all sorts of curated applications in our cluster (like databases, dashboards, visualizations, …). Helm hub is for Kubernetes what Docker hub is for containers. Helm charts are very convenient because they provide a simple to use templating solution. Once you have to maintain similar variants of your deployments e.g. development/production or blue/green runtime environments they are a big time saver.
more about Helm 3 …

Rbac

Role-based access control is a widely used security module that allows for detailed access constraints for all components in a cluster

Ingress

An Ingress serves as an entrypoint into the cluster. In Kubernetes it serves the same purpose that an Apache or NGinx reverse proxy does for a web application. In fact the default Ingress configuration is based on the nginx open source modules. Although all components are pluggable and there are lots of other configuration options which all have their strengths and weaknesses. Its important to note that 2 different Ingress implementations exist. One is maintained by the Kubernetes community and is considered the ‘mainstream’ or default component. The other is maintained by Nginx corporation which is the creator of Nginx.

While its good to habe a choice both are not interchangeable. They have differences in configuration and so you can’t just one replace by the other. Read more about Ingress concepts

The term Ingress is a synonym for a VirtualHost in the Apache2 Universe or Server block in traditional Nginx terminology. The term Ingress controller refers to an Nginx server that is wrapped into a container under control of the kubernetes environment.

A common data flow with an Ingress and 3 services is:

           Cloud / MetalLb
Internet -> LoadBalancer  -> Ingress --> service1  
                                     |-> service2
                                     |-> service3

The same data flow without Ingress requires 3 LoadBalancer instances (which is 3 times as costly in some cloud environments).

           Cloud / MetalLb
Internet --> LoadBalancer  -> service1  
         |-> LoadBalancer  -> service2  
         |-> LoadBalancer  -> service3  

As a side note there are other Ingress replacements available which serve the same purpose but all have their own pros and cons and do not share a common configuration (Envoy, Gloo, Heptio Contour, Istio, Ambassador, …)