K8s

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 - Hetzner

K8s, Hetzner, Ubuntu

Source

https://www.youtube.com/watch?v=dEAtD9PVr_Q

get Host

Build a VM on Hetzner, Ubuntu 22.04

Patch

Patch the Box

apt-get update
apt-get --fix-broken install
apt-get -y upgrade
apt-get install lynx uptimed

Kurl Small

give a try with kurl. the Open Source Kubernetes Installer ;)

time curl https://kurl.sh/ccedeec |bash |tee -a install.md

real	4m5.149s
user	1m26.425s
sys	0m22.249s

Kurl Full

same as small, but with most options enabled

curl https://kurl.sh/13609c3 | sudo bash

Ressource Warning

got a warning as i took a bit a small VM (CX21). Just ignore it.

K8s on Debian12

Debian, K8s

Install Debian 12

or install Debian 11.7 and Upgrade to 12

Setup

3 Nodes

192.168.100.151     k8s-master
192.168.100.152     k8s-worker1
192.168.100.153     k8s-worker2

Locale

export LC_CTYPE=en_US.UTF-8
export LC_ALL=en_US.UTF-8

Kubernetes

https://kubernetes.io/docs/tasks/tools/install-kubectl-linux/
curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

Swap Off

swapoff -a
sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

Install FW

apt-get install ufw
ufw enable

Master

ufw allow 22/tcp
ufw allow 6443/tcp
ufw allow 2379/tcp
ufw allow 2380/tcp
ufw allow 10250/tcp
ufw allow 10251/tcp
ufw allow 10252/tcp
ufw allow 10255/tcp
ufw reload

Worker

ufw allow 22/tcp
ufw allow 10250/tcp
ufw allow 30000:32767/tcp
ufw reload

Containerd

cat << EOF >> /etc/modules-load.d/containerd.conf
overlay
br_netfilter
EOF

modprobe overlay
modprobe br_netfilter

cat << EOF >> /etc/sysctl.d/99-kubernetes-k8s.conf
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
EOF

sysctl --system

Containerd

apt update
apt -y install containerd

Adapt Containerd to Kubernetes

containerd config default > /etc/containerd/config.toml >/dev/null 2>&1

Update config.toml

sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml

Restart Containerd

systemctl enable containerd
systemctl restart containerd

add Kubernetes

apt install gnupg gnupg2 curl software-properties-common -y
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg |gpg --dearmour -o /etc/apt/trusted.gpg.d/cgoogle.gpg
apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"

Kubectl

apt update
apt install kubelet kubeadm kubectl -y
apt-mark hold kubelet kubeadm kubectl

Kube Init on MASTER

kubeadm init --control-plane-endpoint=k8s-master

Downgrade to 1.26

Version 1.27 seems not production ready, so, you may have to downgrade it :(

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