# Initialisation de mon tout premier cluster HA

#### Architecture

<table border="1" id="bkmrk-hostname-ram-cpu-dis" style="border-collapse: collapse; width: 100%; height: 343.05px;"><colgroup><col style="width: 16.6826%;"></col><col style="width: 16.6826%;"></col><col style="width: 16.6826%;"></col><col style="width: 16.6826%;"></col><col style="width: 16.6826%;"></col><col style="width: 16.6826%;"></col></colgroup><tbody><tr style="height: 64.65px;"><td class="align-center" style="height: 64.65px;">##### **Hostname**

</td><td class="align-center" style="height: 64.65px;">##### **RAM**

</td><td class="align-center" style="height: 64.65px;">##### **CPU**

</td><td class="align-center" style="height: 64.65px;">##### **DISQUE**

</td><td class="align-center" style="height: 64.65px;">##### **IP**

</td><td style="height: 64.65px;">##### **FONCTION**

</td></tr><tr style="height: 46.4px;"><td style="height: 46.4px;">k8s-master-1  
</td><td style="height: 46.4px;">4 go</td><td style="height: 46.4px;">2</td><td style="height: 46.4px;">60 SSD + 100 HDD (/opt)</td><td style="height: 46.4px;">192.168.1.101</td><td style="height: 46.4px;">etcd + control-plane</td></tr><tr style="height: 46.4px;"><td style="height: 46.4px;">k8s-master-2</td><td style="height: 46.4px;">4 go</td><td style="height: 46.4px;">2</td><td style="height: 46.4px;">60 SSD + 100 HDD (/opt)</td><td style="height: 46.4px;">192.168.1.102</td><td style="height: 46.4px;">etcd + control-plane</td></tr><tr style="height: 46.4px;"><td style="height: 46.4px;">k8s-master-3</td><td style="height: 46.4px;">4 go</td><td style="height: 46.4px;">2</td><td style="height: 46.4px;">60 SSD + 100 HDD (/opt) </td><td style="height: 46.4px;">192.168.1.103</td><td style="height: 46.4px;">etcd + control-plane</td></tr><tr style="height: 46.4px;"><td style="height: 46.4px;">k8s-worker-1</td><td style="height: 46.4px;">16 go</td><td style="height: 46.4px;">4</td><td style="height: 46.4px;">60 SSD + 100 HDD (/opt)</td><td style="height: 46.4px;">192.168.1.104</td><td style="height: 46.4px;">  
</td></tr><tr style="height: 46.4px;"><td style="height: 46.4px;">k8s-worker-2</td><td style="height: 46.4px;">16 go</td><td style="height: 46.4px;">4</td><td style="height: 46.4px;">60 SSD + 100 HDD (/opt)</td><td style="height: 46.4px;">192.168.1.105</td><td style="height: 46.4px;">  
</td></tr><tr style="height: 46.4px;"><td style="height: 46.4px;">k8s-worker-3</td><td style="height: 46.4px;">16 go</td><td style="height: 46.4px;">4</td><td style="height: 46.4px;">60 SSD + 100 HDD (/opt)</td><td style="height: 46.4px;">192.168.1.106</td><td style="height: 46.4px;">  
</td></tr></tbody></table>

<p class="callout info">Tous les noeuds sont sur debian 13.</p>

#### Plan de déploiement du cluster :

- Préparation du système
- installation des prérequits 
    - conainer.io
    - kubelet
    - kubeadm
    - kubectl
- Préparation du cluster HA (KubeVip)
- Initialisation du cluster
- Configuration du cluster
- Ajout des différents noeud au cluster

#### Préparation du système

<p class="callout warning">Commandes à réaliser sur tous les noeuds</p>

##### 1) Désactivation de la swap

```bash
swapoff -a
```

Désactivation de la swap de manière pérenne :

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

##### 2) Configuration du kernel

Chargement au démarage des modules pour k8s :

```bash
cat <<EOF | tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF
```

Chargement immédiat des modules pour k8s :

```bash
modprobe overlay
modprobe br_netfilter
```

<p class="callout success">Le module overlay permet le fonctionnement du système de fichier OverlayFS.  
Le module br\_netfiltrer permet d'appliquer les iptables à un bridge.</p>

Configuration des paramètres réseaux :

```bash
cat <<EOF | tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.ipv4.ip_forward = 1
EOF
```

<p class="callout success">Permet aux bridges de faire appel au FW iptables  
Permet d'active le routage</p>

Application des paramètres :

```bash
sysctl --system
```


#### installation des prérequits

<p class="callout warning">Commandes à réaliser sur tous les noeuds</p>

##### Installation des packets courrants :

```bash
apt-get update 
apt-get install -y ca-certificates curl gnupg lsb-release htop jq tcpdump ethtool
```

##### Installation de containerd.io

```bash
install -m 0755 -d /etc/apt/keyrings

curl -fsSL https://download.docker.com/linux/debian/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg

chmod a+r /etc/apt/keyrings/docker.gpg

echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] \
  https://download.docker.com/linux/debian bookworm stable" \
  | tee /etc/apt/sources.list.d/docker.list > /dev/null

apt update

apt install -y containerd.io
```

Configuration de containerd :

```bash
containerd config default | sudo tee /etc/containerd/config.toml
```

Activation de containerd :

```bash
systemctl enable containerd
```

Activation de l'emploie de systemd comme gestionnaire de Cgroup :

```bash
sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/g' /etc/containerd/config.toml
```

Redémarage de Containerd :

```bash
systemctl restart containerd
```

##### Installation de kubernet

Installation de kubelet kubeadm et kubectl :

```bash
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.32/deb/Release.key | gpg --dearmor | sudo tee /etc/apt/keyrings/kubernetes-apt-keyring.gpg > /dev/null
sudo chmod 644 /etc/apt/keyrings/kubernetes-apt-keyring.gpg

echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.32/deb/ /" | sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt update

sudo apt install -y kubelet kubeadm kubectl

sudo apt-mark hold kubelet kubeadm kubectl
```

#### Préparation du cluster HA (KubeVip)

<p class="callout warning">Sur tous les noeuds master UNIQUEMENT</p>

```bash
export VIP="192.168.1.100"
export INTERFACE="ens18"
```

<p class="callout info">Ici ens18 correspond à mon interface de prod et 192.168.1.100 correspondra à l'ip qui se "baladera" sur mes noeuds master selon leur disponiblité -&gt; elle n'est pas fixée à un seul endroit.</p>

```bash
KVVERSION=$(curl -sL https://api.github.com/repos/kube-vip/kube-vip/releases/latest | jq -r ".name")
echo "Version kube-vip : $KVVERSION"
```

```bash
sudo mkdir -p /etc/kubernetes/manifests/
# Pull de l'image kube-vip
sudo ctr image pull ghcr.io/kube-vip/kube-vip:$KVVERSION
# Génération du manifeste Static Pod
sudo ctr run --rm --net-host ghcr.io/kube-vip/kube-vip:$KVVERSION vip \
/kube-vip manifest pod \
--interface $INTERFACE \
--address $VIP \
--controlplane \
--services \
--arp \
--leaderElection | sudo tee /etc/kubernetes/manifests/kube-vip.yaml
```

#### Initialisation du cluster

<p class="callout warning">Sur le noeuds k8s-master-1 UNIQUEMENT</p>

Application "à la main" de l'ip vip le temps qu'elle soit gérée par K8S :

```bash
sudo ip addr add 192.168.1.100/32 dev ens18
```

Initialisation du cluster :

```bash
sudo kubeadm init \
--control-plane-endpoint "192.168.1.100:6443" \
--upload-certs \
--pod-network-cidr=10.10.0.0/16
```

```bash
sudo kubeadm init phase upload-certs --upload-certs
```

Configurer kubectl pour l'utilisateur courant :

```bash
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
```

 Vérification du bon déploiement du cluster "basique" :

```bash
kubectl get pods -n kube-system
```

```bash
NAME                                   READY   STATUS    RESTARTS   AGE
etcd-k8s-master-1                      1/1     Running   0          4m57s
kube-apiserver-k8s-master-1            1/1     Running   0          4m57s
kube-controller-manager-k8s-master-1   1/1     Running   0          4m57s
kube-scheduler-k8s-master-1            1/1     Running   0          4m57s
kube-vip-k8s-master-1                  1/1     Running   0          4m57s
```

#### Déploiement du réseau Calico 

```bash
kubectl create -f https://raw.githubusercontent.com/projectcalico/calico/v3.27.0/manifests/tigera-operator.yaml
```

Attendre que l'opérateur ait fini :

```bash
kubectl rollout status deployment tigera-operator -n tigera-operator
```

Déployer les ressources Calico :

```bash
kubectl create -f https://raw.githubusercontent.com/projectcalico/calico/v3.27.0/manifests/custom-resources.yaml
```

Définir le sous réseau de K8S :

```bash
kubectl patch installation default --type=merge -p '{"spec": {"calicoNetwork": {"ipPools": [{"cidr": "10.10.0.0/16", "encapsulation": "VXLANCrossSubnet", "natOutgoing": "Enabled", "nodeSelector": "all()"}]}}}'
```

Suvi des états :

```
watch kubectl get pods -n calico-system
```

#### Configuration du cluster

Désactivation de l'ip VIP "manuelle" :

```bash
sudo ip addr del 192.168.1.100/32 dev ens18
```

Ajout de l'ip vp dans le configmap de kubeadmin :

```
kubectl edit configmap kubeadm-config -n kube-system
```

```yaml
apiVersion: v1
data:
  ClusterConfiguration: |
    apiServer: {}
    apiVersion: kubeadm.k8s.io/v1beta4
    caCertificateValidityPeriod: 87600h0m0s
    certificateValidityPeriod: 8760h0m0s
    certificatesDir: /etc/kubernetes/pki
    clusterName: kubernetes
    controllerManager: {}
--> controlPlaneEndpoint: "192.168.1.100:6443"
```

Ici on ajoute uniquement "controlPlaneEndpoint.

```bash
kubeadm init phase upload-certs --upload-certs
```

Application du label control-plane à k8s-master-1

```bash
kubectl label node k8s-master-1 node-role.kubernetes.io/control-plane=
```

**Génération de la commande permettant d'ajouter des noeuds masters :**

```bash
sudo kubeadm token create --print-join-command --certificate-key $(sudo kubeadm init phase upload-certs --upload-certs | tail -1)
```

**Génération de la commande permettant d'ajouter des noeuds worker :**

```
kubeadm token create --print-join-command
```

#### Ajout des différents noeuds master au cluster

<p class="callout warning">Commandes à exécuter sur les noeuds k8s-master-2 et k8s-master-3</p>

```bash
kubeadm join 192.168.1.100:6443 --token ld3z42.3n2zglgdtoyd2to2 --discovery-token-ca-cert-hash sha256:03d97c70e97b300bb1088fa63f1005d52dcf45d813e6ec535897f2151c8a61c2 --control-plane --certificate-key c9413180b64c612ee58713da91a4d9b77e95bee06b424aa500ebb4b16fb7769d
```


#### Ajout des différents noeuds worker au cluster

<p class="callout warning">Commandes à exécuter sur les noeuds k8s-worker-1, k8s-worker-2 et k8s-worker-3</p>

```yaml
// Envoyer la commande générée par kubeadm token create --print-join-command
```

#### Résultat : 

```bash
kubectl get nodes
```

```python
NAME           STATUS   ROLES           AGE     VERSION
k8s-master-1   Ready    control-plane   81m     v1.32.12
k8s-master-2   Ready    control-plane   6m13s   v1.32.12
k8s-master-3   Ready    control-plane   4m8s    v1.32.12
k8s-worker-1   Ready    <none>          2m3s    v1.32.12
k8s-worker-2   Ready    <none>          115s    v1.32.12
k8s-worker-3   Ready    <none>          105s    v1.32.12
```

<p class="callout success">Félicitation ! Vous venez de déployer votre tout premier cluster Kubernettes !</p>

#### Déployer une solution de stockage

**Installation des prérequits sur TOUS LES NOEUDS :**

```bash
sudo apt-get update
sudo apt-get install -y open-iscsi nfs-common
sudo systemctl enable --now iscsid
```

**Installation de Helm sur le master 1 :**

```bash
curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3
bash get_helm.sh
```

**Préparation et déploiement de Longhorn :**

```bash
helm repo add longhorn https://charts.longhorn.io
helm repo update
```

**Dans le fichier : /root/longhorn-values.yaml :**

```yaml
defaultSettings:
  defaultDataPath: "/opt/longhorn"
```

**Déploiement de longhorn :**

```bash
helm install longhorn longhorn/longhorn \
  --namespace longhorn-system \
  --create-namespace \
  -f /root/longhorn-values.yaml
```

Résultat :

```bash
LAST DEPLOYED: Wed Apr 15 22:49:57 2026
NAMESPACE: longhorn-system
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
Longhorn is now installed on the cluster!

Please wait a few minutes for other Longhorn components such as CSI deployments, Engine Images, and Instance Managers to be initialized.

Visit our documentation at https://longhorn.io/docs/
```

**Vérifications :**

```bash
kubectl get pods -n longhorn-system
```

```bash
NAME                                                READY   STATUS    RESTARTS      AGE
csi-attacher-5bcb65bf95-44fv7                       1/1     Running   1 (66s ago)   2m27s
csi-attacher-5bcb65bf95-jvqxj                       1/1     Running   0             2m27s
csi-attacher-5bcb65bf95-pgf8h                       1/1     Running   0             2m27s
csi-provisioner-5d498c6944-d65sl                    1/1     Running   0             2m27s
csi-provisioner-5d498c6944-dfl96                    1/1     Running   0             2m27s
csi-provisioner-5d498c6944-wvmvs                    1/1     Running   0             2m27s
csi-resizer-6c6474c996-9k94v                        1/1     Running   0             2m26s
csi-resizer-6c6474c996-mjtsj                        1/1     Running   0             2m27s
csi-resizer-6c6474c996-t94bs                        1/1     Running   0             2m26s
csi-snapshotter-5cc5fb45d9-pxz5r                    1/1     Running   0             2m26s
csi-snapshotter-5cc5fb45d9-swr6x                    1/1     Running   0             2m26s
csi-snapshotter-5cc5fb45d9-wsdh6                    1/1     Running   0             2m26s
engine-image-ei-75a03ec3-8r6p4                      1/1     Running   0             3m23s
engine-image-ei-75a03ec3-nmbdp                      1/1     Running   0             3m23s
engine-image-ei-75a03ec3-tl4x2                      1/1     Running   0             3m23s
engine-image-ei-75a03ec3-vcq2q                      1/1     Running   0             3m23s
instance-manager-8904e58b7c0d881b70d813ddd4fe86f4   1/1     Running   0             2m54s
instance-manager-9176dd8e42515fe6146f445c7a1bc3ad   1/1     Running   0             2m53s
instance-manager-9805597396c5db2820496e3f125bc6bc   1/1     Running   0             2m53s
instance-manager-eaeed3ca06747e29c0f3aa8b9557c5c8   1/1     Running   0             2m53s
longhorn-csi-plugin-7vtx8                           3/3     Running   0             2m26s
longhorn-csi-plugin-brx6d                           3/3     Running   0             2m26s
longhorn-csi-plugin-d4fxc                           3/3     Running   0             2m26s
longhorn-csi-plugin-tsrrg                           3/3     Running   0             2m26s
longhorn-driver-deployer-746f54969f-9gmlb           1/1     Running   0             4m5s
longhorn-manager-b7q7k                              2/2     Running   0             4m5s
longhorn-manager-fk6f4                              2/2     Running   0             4m5s
longhorn-manager-xghbf                              2/2     Running   0             4m5s
longhorn-manager-xt4xq                              2/2     Running   0             4m5s
longhorn-ui-5df99fc477-7zt5s                        1/1     Running   0             4m5s
longhorn-ui-5df99fc477-tzwdp                        1/1     Running   0             4m5s
```

<span style="text-decoration: underline;">**Accéder à l'interface graphique :**</span>

```bash
kubectl patch svc longhorn-frontend -n longhorn-system -p '{"spec": {"type": "NodePort"}}'
```

Afficher le port :

```bash
kubectl get svc longhorn-frontend -n longhorn-system
```

**On va utiliser le port :**

```bash
NAME                TYPE       CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
longhorn-frontend   NodePort   10.102.85.80   <none>        80:32555/TCP   6m22s
```

Exemple ici : http://192.168.1.104:32555/#/dashboard

<p class="callout info">On peut utiliser n'importe quelle IP du cluster.</p>

[![image.png](https://docs.nehemiebarkia.fr/uploads/images/gallery/2026-04/scaled-1680-/IGbimage.png)](https://docs.nehemiebarkia.fr/uploads/images/gallery/2026-04/IGbimage.png)

##### Tester le stockage : 

<span style="text-decoration: underline;">**Déclaration du PVC :**</span>

```bash
hello-pvc.yaml
```

```yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: longhorn-hello-pvc
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: longhorn # On utilise le driver Longhorn
  resources:
    requests:
      storage: 1Gi # 1 Go c'est largement assez pour un test
```

**<u>Création d'un conteneur utilisant le PVC : </u>**

```
hello-app.yaml
```

```yaml
apiVersion: v1
kind: Pod
metadata:
  name: hello-longhorn
spec:
  containers:
  - name: hello-world
    image: busybox
    # On écrit la date dans /data/coucou.txt en boucle
    command: ["sh", "-c", "while true; do date >> /data/coucou.txt; echo 'Donnée écrite !'; sleep 5; done"]
    volumeMounts:
    - name: storage-volume
      mountPath: /data
  volumes:
  - name: storage-volume
    persistentVolumeClaim:
      claimName: longhorn-hello-pvc
```

<span style="text-decoration: underline;">**Application des changements :**</span>

```bash
kubectl apply -f hello-pvc.yaml
kubectl apply -f hello-app.yaml
```

<span style="text-decoration: underline;">**Côté interface graphique :**</span>

[![image.png](https://docs.nehemiebarkia.fr/uploads/images/gallery/2026-04/scaled-1680-/jL1image.png)](https://docs.nehemiebarkia.fr/uploads/images/gallery/2026-04/jL1image.png)

<span style="text-decoration: underline;">**Suppression du pod :** </span>

```bash
kubectl delete pod hello-longhorn
```

<span style="text-decoration: underline;">**Suppression du pvc :** </span>

```
kubectl delete pvc longhorn-hello-pvc
```

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