Grafana + Prometheus: Monitoring Stack

# Latest version from https://github.com/prometheus/node_exporter/releases
NODE_EXPORTER_VERSION="1.8.2"

cd /tmp
wget https://github.com/prometheus/node_exporter/releases/download/v${NODE_EXPORTER_VERSION}/node_exporter-${NODE_EXPORTER_VERSION}.linux-amd64.tar.gz
tar xvf node_exporter-${NODE_EXPORTER_VERSION}.linux-amd64.tar.gz
mv node_exporter-${NODE_EXPORTER_VERSION}.linux-amd64/node_exporter /usr/local/bin/

useradd --no-create-home --shell /bin/false node_exporter

cat > /etc/systemd/system/node_exporter.service << 'EOF'
[Unit]
Description=Prometheus Node Exporter
After=network.target

[Service]
User=node_exporter
Group=node_exporter
ExecStart=/usr/local/bin/node_exporter \
  --web.listen-address=":9100" \
  --collector.systemd \
  --collector.processes
Restart=always

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl enable --now node_exporter

PROMETHEUS_VERSION="2.53.0"

cd /tmp
wget https://github.com/prometheus/prometheus/releases/download/v${PROMETHEUS_VERSION}/prometheus-${PROMETHEUS_VERSION}.linux-amd64.tar.gz
tar xvf prometheus-${PROMETHEUS_VERSION}.linux-amd64.tar.gz

mv prometheus-${PROMETHEUS_VERSION}.linux-amd64/prometheus /usr/local/bin/
mv prometheus-${PROMETHEUS_VERSION}.linux-amd64/promtool /usr/local/bin/

mkdir -p /etc/prometheus /var/lib/prometheus
mv prometheus-${PROMETHEUS_VERSION}.linux-amd64/consoles /etc/prometheus/
mv prometheus-${PROMETHEUS_VERSION}.linux-amd64/console_libraries /etc/prometheus/

useradd --no-create-home --shell /bin/false prometheus
chown -R prometheus:prometheus /etc/prometheus /var/lib/prometheus

cat > /etc/prometheus/prometheus.yml << 'EOF'
global:
  scrape_interval: 15s
  evaluation_interval: 15s

scrape_configs:
  - job_name: "prometheus"
    static_configs:
      - targets: ["localhost:9090"]

  - job_name: "node"
    static_configs:
      - targets: ["localhost:9100"]
        labels:
          instance: "my-vps"
          env: "production"
EOF

cat > /etc/systemd/system/prometheus.service << 'EOF'
[Unit]
Description=Prometheus
After=network.target

[Service]
User=prometheus
Group=prometheus
ExecStart=/usr/local/bin/prometheus \
  --config.file=/etc/prometheus/prometheus.yml \
  --storage.tsdb.path=/var/lib/prometheus \
  --storage.tsdb.retention.time=30d \
  --web.listen-address=":9090" \
  --web.enable-lifecycle
Restart=always

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl enable --now prometheus

# Add Grafana repository
apt install -y apt-transport-https software-properties-common
wget -q -O - https://packages.grafana.com/gpg.key | gpg --dearmor > /etc/apt/keyrings/grafana.gpg
echo "deb [signed-by=/etc/apt/keyrings/grafana.gpg] https://packages.grafana.com/oss/deb stable main" > /etc/apt/sources.list.d/grafana.list

apt update
apt install -y grafana

systemctl enable --now grafana-server

ssh -L 3000:localhost:3000 root@SERVER_IP
# Then visit http://localhost:3000

server {
    listen 443 ssl;
    server_name grafana.yourdomain.com;

    ssl_certificate /etc/letsencrypt/live/grafana.yourdomain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/grafana.yourdomain.com/privkey.pem;

    location / {
        proxy_pass http://localhost: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;
    }
}

# CPU usage %
100 - (avg by (instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100)

# Available RAM in GB
node_memory_MemAvailable_bytes / 1024^3

# Disk usage %
(1 - node_filesystem_avail_bytes{mountpoint="/"} / node_filesystem_size_bytes{mountpoint="/"}) * 100

# Network traffic in Mbps
rate(node_network_transmit_bytes_total{device="eth0"}[5m]) * 8 / 1024^2

# Load average 1m
node_load1

# Create a Telegram bot: talk to @BotFather → /newbot
# Get the TOKEN and CHAT_ID

nano /etc/grafana/grafana.ini

[alerting]
enabled = true

[unified_alerting]
enabled = true

scrape_configs:
  - job_name: "node"
    static_configs:
      - targets:
          - "localhost:9100"         # main server
          - "10.0.0.2:9100"          # secondary server (private network)
          - "1.2.3.4:9100"           # another VPS (expose only if protected)
        labels:
          env: "production"