Install and configure Grafana with Prometheus for system monitoring

#!/usr/bin/env bash
set -euo pipefail

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# Default versions
PROMETHEUS_VERSION="2.45.0"
NODE_EXPORTER_VERSION="1.6.1"
GRAFANA_VERSION="10.2.2"

# Usage function
usage() {
    echo "Usage: $0 [OPTIONS]"
    echo "Install and configure Grafana with Prometheus for system monitoring"
    echo ""
    echo "Options:"
    echo "  -h, --help           Show this help message"
    echo "  --prometheus-port    Prometheus port (default: 9090)"
    echo "  --grafana-port       Grafana port (default: 3000)"
    echo "  --node-exporter-port Node exporter port (default: 9100)"
    exit 1
}

# Parse arguments
PROMETHEUS_PORT=9090
GRAFANA_PORT=3000
NODE_EXPORTER_PORT=9100

while [[ $# -gt 0 ]]; do
    case $1 in
        -h|--help)
            usage
            ;;
        --prometheus-port)
            PROMETHEUS_PORT="$2"
            shift 2
            ;;
        --grafana-port)
            GRAFANA_PORT="$2"
            shift 2
            ;;
        --node-exporter-port)
            NODE_EXPORTER_PORT="$2"
            shift 2
            ;;
        *)
            echo -e "${RED}Unknown option: $1${NC}"
            usage
            ;;
    esac
done

# Cleanup function for rollback
cleanup() {
    echo -e "${RED}[ERROR] Installation failed. Cleaning up...${NC}"
    systemctl stop prometheus node_exporter grafana-server 2>/dev/null || true
    systemctl disable prometheus node_exporter grafana-server 2>/dev/null || true
    userdel prometheus 2>/dev/null || true
    userdel node_exporter 2>/dev/null || true
    userdel grafana 2>/dev/null || true
    rm -rf /etc/prometheus /var/lib/prometheus /usr/local/bin/prometheus /usr/local/bin/promtool /usr/local/bin/node_exporter
    rm -f /etc/systemd/system/prometheus.service /etc/systemd/system/node_exporter.service
}

trap cleanup ERR

# Check prerequisites
if [[ $EUID -ne 0 ]]; then
   echo -e "${RED}This script must be run as root${NC}"
   exit 1
fi

# Detect distribution
if [ -f /etc/os-release ]; then
    . /etc/os-release
    case "$ID" in
        ubuntu|debian) 
            PKG_MGR="apt"
            PKG_INSTALL="apt install -y"
            PKG_UPDATE="apt update && apt upgrade -y"
            ;;
        almalinux|rocky|centos|rhel|ol|fedora) 
            PKG_MGR="dnf"
            PKG_INSTALL="dnf install -y"
            PKG_UPDATE="dnf update -y"
            ;;
        amzn) 
            PKG_MGR="yum"
            PKG_INSTALL="yum install -y"
            PKG_UPDATE="yum update -y"
            ;;
        *) 
            echo -e "${RED}Unsupported distribution: $ID${NC}"
            exit 1
            ;;
    esac
else
    echo -e "${RED}Cannot detect distribution${NC}"
    exit 1
fi

echo -e "${GREEN}[1/12] Updating system packages...${NC}"
$PKG_UPDATE

echo -e "${GREEN}[2/12] Installing required packages...${NC}"
$PKG_INSTALL wget tar curl

echo -e "${GREEN}[3/12] Creating system users...${NC}"
useradd --no-create-home --shell /bin/false prometheus 2>/dev/null || true
useradd --no-create-home --shell /bin/false node_exporter 2>/dev/null || true
useradd --system --no-create-home --shell /bin/false grafana 2>/dev/null || true

echo -e "${GREEN}[4/12] Creating Prometheus directories...${NC}"
mkdir -p /etc/prometheus /var/lib/prometheus
chown prometheus:prometheus /etc/prometheus /var/lib/prometheus
chmod 755 /etc/prometheus /var/lib/prometheus

echo -e "${GREEN}[5/12] Downloading and installing Prometheus...${NC}"
cd /tmp
wget -q "https://github.com/prometheus/prometheus/releases/download/v${PROMETHEUS_VERSION}/prometheus-${PROMETHEUS_VERSION}.linux-amd64.tar.gz"
tar xzf "prometheus-${PROMETHEUS_VERSION}.linux-amd64.tar.gz"
cp "prometheus-${PROMETHEUS_VERSION}.linux-amd64/prometheus" /usr/local/bin/
cp "prometheus-${PROMETHEUS_VERSION}.linux-amd64/promtool" /usr/local/bin/
chown prometheus:prometheus /usr/local/bin/prometheus /usr/local/bin/promtool
chmod 755 /usr/local/bin/prometheus /usr/local/bin/promtool

echo -e "${GREEN}[6/12] Downloading and installing Node Exporter...${NC}"
wget -q "https://github.com/prometheus/node_exporter/releases/download/v${NODE_EXPORTER_VERSION}/node_exporter-${NODE_EXPORTER_VERSION}.linux-amd64.tar.gz"
tar xzf "node_exporter-${NODE_EXPORTER_VERSION}.linux-amd64.tar.gz"
cp "node_exporter-${NODE_EXPORTER_VERSION}.linux-amd64/node_exporter" /usr/local/bin/
chown node_exporter:node_exporter /usr/local/bin/node_exporter
chmod 755 /usr/local/bin/node_exporter

echo -e "${GREEN}[7/12] Configuring Prometheus...${NC}"
cat > /etc/prometheus/prometheus.yml << EOF
global:
  scrape_interval: 15s
  evaluation_interval: 15s

scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets: ['localhost:${PROMETHEUS_PORT}']

  - job_name: 'node_exporter'
    static_configs:
      - targets: ['localhost:${NODE_EXPORTER_PORT}']

  - job_name: 'grafana'
    static_configs:
      - targets: ['localhost:${GRAFANA_PORT}']
EOF
chown prometheus:prometheus /etc/prometheus/prometheus.yml
chmod 644 /etc/prometheus/prometheus.yml

echo -e "${GREEN}[8/12] Creating systemd services...${NC}"
cat > /etc/systemd/system/prometheus.service << EOF
[Unit]
Description=Prometheus
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.console.templates=/etc/prometheus/consoles \\
    --web.console.libraries=/etc/prometheus/console_libraries \\
    --web.listen-address=0.0.0.0:${PROMETHEUS_PORT} \\
    --web.enable-lifecycle
Restart=always

[Install]
WantedBy=multi-user.target
EOF

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

[Service]
User=node_exporter
Group=node_exporter
Type=simple
ExecStart=/usr/local/bin/node_exporter --web.listen-address=0.0.0.0:${NODE_EXPORTER_PORT}
Restart=always

[Install]
WantedBy=multi-user.target
EOF

echo -e "${GREEN}[9/12] Installing Grafana...${NC}"
case "$ID" in
    ubuntu|debian)
        $PKG_INSTALL software-properties-common
        wget -q -O - https://packages.grafana.com/gpg.key | apt-key add -
        echo "deb https://packages.grafana.com/oss/deb stable main" > /etc/apt/sources.list.d/grafana.list
        apt update
        $PKG_INSTALL grafana
        ;;
    *)
        cat > /etc/yum.repos.d/grafana.repo << EOF
[grafana]
name=grafana
baseurl=https://packages.grafana.com/oss/rpm
repo_gpgcheck=1
enabled=1
gpgcheck=1
gpgkey=https://packages.grafana.com/gpg.key
sslverify=1
sslcacert=/etc/pki/tls/certs/ca-bundle.crt
EOF
        $PKG_INSTALL grafana
        ;;
esac

echo -e "${GREEN}[10/12] Starting services...${NC}"
systemctl daemon-reload
systemctl enable prometheus node_exporter grafana-server
systemctl start prometheus node_exporter grafana-server

echo -e "${GREEN}[11/12] Configuring firewall...${NC}"
if command -v ufw &> /dev/null; then
    ufw allow ${PROMETHEUS_PORT}/tcp
    ufw allow ${NODE_EXPORTER_PORT}/tcp
    ufw allow ${GRAFANA_PORT}/tcp
elif command -v firewall-cmd &> /dev/null; then
    firewall-cmd --permanent --add-port=${PROMETHEUS_PORT}/tcp
    firewall-cmd --permanent --add-port=${NODE_EXPORTER_PORT}/tcp
    firewall-cmd --permanent --add-port=${GRAFANA_PORT}/tcp
    firewall-cmd --reload
fi

echo -e "${GREEN}[12/12] Verifying installation...${NC}"
sleep 5

# Verification checks
for service in prometheus node_exporter grafana-server; do
    if systemctl is-active --quiet $service; then
        echo -e "${GREEN}✓ $service is running${NC}"
    else
        echo -e "${RED}✗ $service is not running${NC}"
        exit 1
    fi
done

# Check if ports are listening
for port in $PROMETHEUS_PORT $NODE_EXPORTER_PORT $GRAFANA_PORT; do
    if netstat -tuln 2>/dev/null | grep -q ":$port " || ss -tuln 2>/dev/null | grep -q ":$port "; then
        echo -e "${GREEN}✓ Port $port is listening${NC}"
    else
        echo -e "${YELLOW}⚠ Port $port may not be ready yet${NC}"
    fi
done

# Cleanup temporary files
rm -rf /tmp/prometheus-* /tmp/node_exporter-*

echo -e "${GREEN}"
echo "=============================================="
echo "Installation completed successfully!"
echo "=============================================="
echo "Prometheus: http://localhost:${PROMETHEUS_PORT}"
echo "Grafana: http://localhost:${GRAFANA_PORT}"
echo "Default Grafana credentials: admin/admin"
echo "Node Exporter: http://localhost:${NODE_EXPORTER_PORT}"
echo "=============================================="
echo -e "${NC}"