Kubernetes

K8s - DigitalOcean

Do, K8s, Kubernetes

Deploy Sampleapp on Kuberentes …

Prerequisite

  • Domain “kubbi.xyz”, ns1.digitalocean.com, ns2, ns3 …
  • Digital Ocean Login

Doku

https://docs.digitalocean.com/products/kubernetes/getting-started/operational-readiness/

Build Kubbi Cluster

Build Cluster with WebGUI or CLI

via CLI

time doctl kubernetes cluster create prod001 --region fra1 --node-pool "size=s-2vcpu-2gb;auto-scale=true;min-nodes=3;max-nodes=5"
  • FRA1
  • 3 Nodes
  • 2 CPU
  • 2 GB RAM
  • 60 GB Disk
  • Costs: 54 USD/Mt!

Connecting and managing this cluster

doctl kubernetes cluster kubeconfig save 4375b470-ebe8-4ccb-925a-345df364dfbd

user@mac % doctl kubernetes cluster kubeconfig save 4375b470-ebe8-4ccb-925a-345df364dfbd


Notice: Adding cluster credentials to kubeconfig file found in "/Users/user/.kube/config"
Notice: Setting current-context to do-fra1-k8s-1-28-2-do-0-fra1-1702031438694

kubectl config get-contexts

kubectl config get-contexts

user@mac % kubectl config get-contexts

CURRENT   NAME                                         CLUSTER                                      AUTHINFO                                           NAMESPACE
*         do-fra1-prod-cluster-01                      do-fra1-prod-cluster-01                      do-fra1-prod-cluster-01-admin

kubectl cluster-info

kubectl cluster-info

user@mac % kubectl cluster-info

Kubernetes control plane is running at https://f179692f-aeac-4f9c-af3b-2422897ea578.k8s.ondigitalocean.com
CoreDNS is running at https://f179692f-aeac-4f9c-af3b-2422897ea578.k8s.ondigitalocean.com/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

kubectl version

kubectl version

user@mac % kubectl version

Client Version: v1.28.2
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: v1.28.2

kubectl get nodes

kubectl get nodes

user@mac % kubectl get nodes

NAME                    STATUS   ROLES    AGE     VERSION
prod-cluster-01-xa856   Ready    <none>   3m59s   v1.28.2
prod-cluster-01-xa85a   Ready    <none>   4m7s    v1.28.2

Install Nginx Ingress Controller

  • via GUI / Marketplace / NGINX Ingress Controller

show lbl status

doctl compute load-balancer list --format IP,ID,Name,Status

user@mac % doctl compute load-balancer list --format IP,ID,Name,Status

IP    ID                                      Name                                Status
      55d7381d-9bcd-4f8f-905e-e90efd09f03e    a6554a9aff1a340e986d48431e19cca9    new

no ip yet … wait …

K8s - Kubernetes

Cloud, K8s, Kubernetes

Show Contexts

kubectl config get-contexts
CURRENT   NAME                           CLUSTER                        AUTHINFO                             NAMESPACE
*         do-fra1-k8s-1-24-xxxxxxxxxxx   do-fra1-k8s-1-24-xxxxxxxxxxx   do-fra1-k8s-1-24-xxxxxxxxxxxxxxxxx
          do-fra1-k8s-1-25-xxxxxxxxxxx   do-fra1-k8s-1-25-xxxxxxxxxxx   do-fra1-k8s-1-25-xxxxxxxxxxxxxxxxx
          do-fra1-k8s-xxxxx              do-fra1-k8s-xxxxx              do-fra1-k8s-xxxxxxxxxxx

Delete old Contexts

kubectl config delete-context do-fra1-k8s-xxxxx
Any Comments ?

sha256: f12aa09936d175b3e23f2eebc1c152675d68dce6096b9ec02d7f8429b954b4fe

K3s - Kubernetes

Cloud, K3s, Kubernetes

Let’s give a Try with Kubernetes Mini, K3s

Source

Overview

TestSetup

Booting a few VM’s on my ESX Host. All of them got 4 CPU’s, 32 GB RAM, 100G Disk

1 MasterNode

  • Master

3 WorkerNodes

  • Worker01
  • Worker02
  • Worker03

All Maschines are Running Debian Latest, that’s Version 11.6 at the Moment

Setup Master

curl -sfL https://get.k3s.io | sh -

root@master:~/bin/test_kubernetes# curl -sfL https://get.k3s.io | sh -
[INFO]  Finding release for channel stable
[INFO]  Using v1.25.4+k3s1 as release
[INFO]  Downloading hash https://github.com/k3s-io/k3s/releases/download/v1.25.4+k3s1/sha256sum-amd64.txt
[INFO]  Downloading binary https://github.com/k3s-io/k3s/releases/download/v1.25.4+k3s1/k3s
[INFO]  Verifying binary download
[INFO]  Installing k3s to /usr/local/bin/k3s
[INFO]  Skipping installation of SELinux RPM
[INFO]  Creating /usr/local/bin/kubectl symlink to k3s
[INFO]  Creating /usr/local/bin/crictl symlink to k3s
[INFO]  Skipping /usr/local/bin/ctr symlink to k3s, command exists in PATH at /usr/bin/ctr
[INFO]  Creating killall script /usr/local/bin/k3s-killall.sh
[INFO]  Creating uninstall script /usr/local/bin/k3s-uninstall.sh
[INFO]  env: Creating environment file /etc/systemd/system/k3s.service.env
[INFO]  systemd: Creating service file /etc/systemd/system/k3s.service
[INFO]  systemd: Enabling k3s unit
Created symlink /etc/systemd/system/multi-user.target.wants/k3s.service → /etc/systemd/system/k3s.service.
[INFO]  systemd: Starting k3s

Show Nodes

kubectl get nodes

root@master:~/bin/test_kubernetes# kubectl get nodes
NAME     STATUS   ROLES                  AGE   VERSION
master   Ready    control-plane,master   70s   v1.25.4+k3s1

Show Token

cat /var/lib/rancher/k3s/server/node-token 
K10032f55153f52072a1e41f80f06551078dece476a44217e5a06facdfa6fd0f985::server:a70b4452634b7d2c4f9d33ab8808eb19

on all Worker Nodes

update hosts as root