Exercise 1 - Basic kubectl

Exercise 1 - Basic kubectl

Listing nodes

kubectl get nodes

Create and delete a namespace

kubectl create namespace workshop
kubectl delete namespace workshop

Lots of things can be done with params to kubectl - but we prefer descriptors

Getting a template descriptor via kubectl

kubectl create namespace workshop --dry-run=client -o yaml

Applying a descriptor

kubectl apply -f <filename>.yaml

Exercise

The aim here is to deploy nginx - reading index.html from config - with ingress to service to deployment routing.

The following diagram (easiest to see on github - where it should be rendered) shows what we want to achive (although in this exercise we will only work with http - not https).

flowchart LR
    CM["`**Config Map**
    contains index.html`"]

    subgraph D[Deployment]

    P1["`**Nginx**
    port: 80`"]

    P2["`**Nginx**
    port: 80`"]

    end

    S["`**Service**
    port: 8080
    targetPort: 80`"]

    subgraph IC[Ingress Controller]
    I[Ingress]
    end

    HTTP([HTTP])
    HTTPS([HTTPS])

    HTTP-->|80|IC
    HTTPS-->|443|IC

    I-->|8080|S

    S-->|80|D

    CM-->|Mount index.html|P1
    CM-->|Mount index.html|P2

Loading

For each of these use either k9s or kubectl get to check the result

kubectl apply -f namespace.yaml
kubectl apply -f config.yaml
kubectl apply -f deployment.yaml

Use k9s or kubectl to get a port-forward setup - test in a browser.

Add a service:

kubectl apply -f service.yaml

It should create a ClusterIP service.

Test out making it a node port:

type: NodePort

Simply edit and reapply. Then get it - you should see a value under ports > nodePort - test it by hitting http://IP-of-any-node:nodeport/

Less than ideal. We can test LoadBalancer - k3s by default includes klipper load balancer.

type: LoadBalancer

You can now test by hitting http://IP-of-any-node:8080/ - since that is the port the service listens to.

Finally - let's add an ingress - we don't really want to hit IPs and ports.

Set service back to no type (defaults to ClusterIP) and then:

kubectl apply -f ingress.yaml

This example will listen on port 8080 - so - here - you may have to adjust the hostname and you will probably have to test inside one of the VMs where /etc/hosts is setup