Installazione KuberMatti

Prereq: Iso Oracle linux 8.9 - 4VCPU 8Gbyte di RAM - 32Gbyte disco

Tutto in inglese solo tastiera e Timezone

Software selection: Minimal Install

Partizione: ol-root 30GiB - /boot 1024Mbyte

Settare in installazione IP e Hostname.

Settare Root Password

yum update -y;
systemctl disable firewalld
systemctl stop firewalld
reboot

# Set SELinux in permissive mode (effectively disabling it)
sudo setenforce 0
sudo sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

yum install net-tools -y;
yum install curl -y;
yum install wget -y;
sudo yum install -y yum-utils;
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo;
sudo yum install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin;
sudo systemctl start docker;
sudo systemctl enable docker;
sudo docker run hello-world;

Mettere a posto il file hosts con la risoluzione dei nodi es.:

172.16.1.200 kuber01 kuber01.gazzi.net
172.16.1.201 kuber02 kuber02.gazzi.net

FATE SNAP!!

reboot

# This overwrites any existing configuration in /etc/yum.repos.d/kubernetes.repo
cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://pkgs.k8s.io/core:/stable:/v1.30/rpm/
enabled=1
gpgcheck=1
gpgkey=https://pkgs.k8s.io/core:/stable:/v1.30/rpm/repodata/repomd.xml.key
exclude=kubelet kubeadm kubectl cri-tools kubernetes-cni
EOF

sudo yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
sudo systemctl enable --now kubelet

sudo modprobe overlay
sudo modprobe br_netfilter

vi /etc/sysctl.d/kubernetes.conf

net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1

sudo sysctl --system

sudo reboot

ATTENZIONE SOLO SUL NODO PRINCIPALE:

kubeadm init (attenzione mettete l'opzione dell'ip)

# see what changes would be made, returns nonzero returncode if different
kubectl get configmap kube-proxy -n kube-system -o yaml | \
sed -e "s/strictARP: false/strictARP: true/" | \
kubectl diff -f - -n kube-system

# actually apply the changes, returns nonzero returncode on errors only
kubectl get configmap kube-proxy -n kube-system -o yaml | \
sed -e "s/strictARP: false/strictARP: true/" | \
kubectl apply -f - -n kube-system

kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.14.5/config/manifests/metallb-native.yaml  

kubectl create secret generic -n metallb-system memberlist --from-literal=secretkey="$(openssl rand -base64 128)"

Crea un file metallb-config.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  namespace: metallb-system
  name: config
data:
  config: |
    address-pools:
    - name: default
      protocol: layer2
      addresses:
      - 172.16.1.150-172.16.1.160  # intervallo IP desiderato

kubectl apply -f metallb-config.yaml

Crea un file YAML per il deployment di Nginx, chiamato nginx-deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        ports:
        - containerPort: 80

kubectl apply -f nginx-deployment.yaml

Crea un file YAML per il servizio, chiamato nginx-service.yaml:

apiVersion: v1
kind: Service
metadata:
  name: nginx-service
spec:
  type: LoadBalancer
  loadBalancerIP: 172.16.1.150  # IP statico desiderato
  selector:
    app: nginx
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80 

kubectl apply -f nginx-service.yaml