# snippets for k3s ## Install k3s https://k3s.io/: ``` curl -sfL https://get.k3s.io | sh - ``` ## Disable traeffic-ingress: edit /etc/systemd/system/k3s.service: ``` [...] ExecStart=/usr/local/bin/k3s \ server --disable traefik \ [...] ``` finally `systemctl daemon-reload` and `systemctl restart k3s` ## Enable nginx-ingress ### Installation https://kubernetes.github.io/ingress-nginx/deploy/#bare-metal ### Change service type from NodePort to LoadBalancer `kubectl edit service -n ingress-nginx` and change `type: NodePort` to `type: LoadBalancer` Port 80 and 443 should listen now on an *External-IP* `kubectl get all --all-namespaces`: ``` [...] NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE [...] ingress-nginx service/ingress-nginx-controller-admission ClusterIP 10.43.174.128 443/TCP 35m ingress-nginx service/ingress-nginx-controller LoadBalancer 10.43.237.255 10.62.94.246 80:30312/TCP,443:30366/TCP 35m [...] ``` Test: `curl -s http://` should return well known nginx-404-page: ``` dominik@muggler:~$ curl -s http://10.62.94.246 404 Not Found

404 Not Found

nginx/1.19.1 ``` ### Enable nginx-ingress tcp- and udp-services for apps other than http/s `kubectl edit deployment -n ingress-nginx` and search for `spec:`/`template`/`spec`/`containers` section: ``` [...] spec: [...] template: metadata: creationTimestamp: null labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx spec: containers: - args: - /nginx-ingress-controller - --election-id=ingress-controller-leader - --ingress-class=nginx - --configmap=ingress-nginx/ingress-nginx-controller - --validating-webhook=:8443 - --validating-webhook-certificate=/usr/local/certificates/cert - --validating-webhook-key=/usr/local/certificates/key *** ADD >>> - --tcp-services-configmap=ingress-nginx/tcp-services <<< ADD *** *** ADD >>> - --udp-services-configmap=ingress-nginx/udp-services <<< ADD *** env: [...] ``` ### Deploy nginx-service and expose via nginx-ingress on TCP-port 9000 my-nginx-deployment.yml: ``` apiVersion: apps/v1 kind: Deployment metadata: name: my-nginx spec: selector: matchLabels: run: my-nginx replicas: 1 template: metadata: labels: run: my-nginx spec: containers: - name: my-nginx image: nginx:alpine ports: - containerPort: 80 --- apiVersion: v1 kind: Service metadata: name: my-nginx labels: run: my-nginx spec: ports: - port: 80 protocol: TCP selector: run: my-nginx ``` Apply with `kubectl apply -f my-nginx-deployment.yml`: ``` deployment.apps/my-nginx created service/my-nginx created configmap/tcp-services created ``` Test: `kubectl get all`: ``` [...] NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE [...] service/my-nginx ClusterIP 10.43.118.13 80/TCP 99s [...] ``` Expose my-nginx app on nginx-ingress TCP-port 9000: `kubectl edit service -n ingress-nginx` Find the `ports:`-section of the `ingress-nginx-controller` service and *ADD* the definition for port 9000: ``` [...] spec: clusterIP: 10.43.237.255 externalTrafficPolicy: Cluster ports: - name: http nodePort: 30312 port: 80 protocol: TCP targetPort: http - name: https nodePort: 30366 port: 443 protocol: TCP targetPort: https *** ADD >>> - name: proxied-tcp-9000 port: 9000 protocol: TCP targetPort: 9000 <<< ADD *** [...] ``` Finally, we need to glue nginx-ingress with the my-nginx app. This will be done with the config-map `tcp-services-config-map.yml` referenced earlier in the nginx-ingress deployment definition: ``` --- apiVersion: v1 kind: ConfigMap metadata: name: tcp-services namespace: ingress-nginx data: 9000: "default/my-nginx:80::PROXY" ``` Apply with `kubectl apply -f tcp-services-config-map.yml`: ``` configmap/tcp-services created ``` Verify nginx-ingress is listening on port 9000 with `kubectl get all --all-namespaces`: ``` [...] NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE [...] ingress-nginx service/ingress-nginx-controller LoadBalancer 10.43.237.255 10.62.94.246 80:30312/TCP,443:30366/TCP,9000:31460/TCP 71m [...] ``` Test: ``` dominik@muggler:~$ curl -s http://10.62.94.246:9000 400 Bad Request

400 Bad Request

nginx/1.19.2 ```