Prometheus - Grafana - Node Exporter

🧩 Installation complète : Prometheus + Node Exporter + Grafana

1. Installation de Prometheus

1.1 Télécharger Prometheus

bash:
cd /opt
sudo wget https://github.com/prometheus/prometheus/releases/latest/download/prometheus-linux-amd64.tar.gz
sudo tar -xzf prometheus-linux-amd64.tar.gz
sudo mv prometheus-*/ prometheus

1.2 Créer l’utilisateur système

bash:
sudo useradd --no-create-home --shell /usr/sbin/nologin prometheus

1.3 Déplacer les binaires

bash:
sudo mv /opt/prometheus/prometheus /usr/local/bin/
sudo mv /opt/prometheus/promtool /usr/local/bin/

1.4 Créer les dossiers

bash:
sudo mkdir /etc/prometheus
sudo mkdir /var/lib/prometheus

1.5 Déplacer les fichiers de configuration

bash:
sudo mv /opt/prometheus/consoles /etc/prometheus/
sudo mv /opt/prometheus/console_libraries /etc/prometheus/
sudo mv /opt/prometheus/prometheus.yml /etc/prometheus/

1.6 Permissions

bash:
sudo chown -R prometheus:prometheus /etc/prometheus /var/lib/prometheus

1.7 Service systemd Prometheus

/etc/systemd/system/prometheus.service :

ini:
[Unit]
Description=Prometheus Monitoring
Wants=network-online.target
After=network-online.target

[Service]
User=prometheus
Group=prometheus
Type=simple
ExecStart=/usr/local/bin/prometheus \
 --config.file=/etc/prometheus/prometheus.yml \
 --storage.tsdb.path=/var/lib/prometheus \
 --web.listen-address=0.0.0.0:9090

[Install]
WantedBy=multi-user.target

1.8 Activer & démarrer

bash:
sudo systemctl daemon-reload
sudo systemctl enable --now prometheus

2. Installation de Node Exporter

2.1 Télécharger

bash:
cd /opt
sudo wget https://github.com/prometheus/node_exporter/releases/latest/download/node_exporter-linux-amd64.tar.gz
sudo tar -xzf node_exporter-linux-amd64.tar.gz
sudo mv node_exporter-*/ node_exporter

2.2 Créer utilisateur

bash:
sudo useradd --no-create-home --shell /usr/sbin/nologin nodeusr

2.3 Déplacer le binaire

bash:
sudo mv /opt/node_exporter/node_exporter /usr/local/bin/
sudo chown nodeusr:nodeusr /usr/local/bin/node_exporter

2.4 Service systemd Node Exporter

/etc/systemd/system/node_exporter.service :

ini:
[Unit]
Description=Node Exporter
After=network.target

[Service]
User=nodeusr
Group=nodeusr
Type=simple
ExecStart=/usr/local/bin/node_exporter

[Install]
WantedBy=multi-user.target

2.5 Activer & démarrer

bash:
sudo systemctl daemon-reload
sudo systemctl enable --now node_exporter

3. Installation de Grafana

3.1 Dépôt officiel

bash:
sudo apt-get install -y apt-transport-https software-properties-common wget
wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add -
echo "deb https://packages.grafana.com/oss/deb stable main" | sudo tee /etc/apt/sources.list.d/grafana.list
sudo apt update
sudo apt install grafana

3.2 Activer & démarrer

bash:
sudo systemctl enable --now grafana-server

4. Reverse Proxy NGINX (Prometheus, Grafana, Node Exporter)

4.1 Prometheus (/prometheus/)

code nginx: 
location = /prometheus {
   return 301 /prometheus/;
}

location ^~ /prometheus/ {
   proxy_pass http://127.0.0.1:9090/;
   proxy_set_header Host $host;
   proxy_set_header X-Real-IP $remote_addr;
   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
   proxy_set_header X-Forwarded-Proto $scheme;
   proxy_redirect off;
}

4.2 Grafana (/grafana/)

⚠️ Pas de slash final dans proxy_pass ⚠️ root_url doit être configuré /etc/grafana/grafana.ini

ini:
[server]
root_url = %(protocol)s://%(domain)s/grafana/
serve_from_sub_path = true

NGINX :

code nginx:
location = /grafana {
   return 301 /grafana/;
}

location ^~ /grafana/ {
   proxy_pass http://127.0.0.1:3000;
   proxy_set_header Host $host;
   proxy_set_header X-Real-IP $remote_addr;
   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
   proxy_set_header X-Forwarded-Proto $scheme;
   proxy_redirect off;
}

4.3 Node Exporter (/metrics/)

code nginx:
location /metrics/ {
   proxy_pass http://127.0.0.1:9100/metrics;
   proxy_set_header Host $host;
   proxy_set_header X-Real-IP $remote_addr;
   proxy_redirect off;
}

5. Vérifications finales

5.1 Services

bash: 
systemctl status prometheus
systemctl status node_exporter
systemctl status grafana-server

5.2 Ports

bash:
ss -ltnp | grep -E "9090|9100|3000"

5.3 Reverse proxy

bash:
curl -I https://IP/prometheus/ --insecure
curl -I https://IP/grafana/ --insecure
curl -I https://IP/metrics/ --insecure

6. Pièges à éviter (résumés)

❌ Ne jamais mettre de .save ou .bak dans sites-enabled

❌ Ne jamais oublier le / final pour Prometheus & Node Exporter

❌ Ne jamais mettre de / final pour Grafana

❌ Toujours rediriger /app → /app/

❌ Toujours utiliser ^~ /app/ pour éviter les conflits

❌ Toujours configurer root_url pour Grafana