#!/bin/bash

# This script adds a new node to the Prometheus configuration file
# Supports optional Basic Authentication (username/password)
# Use: sudo ./add_node.sh <SERVER_IP> [USERNAME] [PASSWORD]

if [ -z "$1" ]; then
    echo "--- Prometheus Node Adder ---"
    read -p "Enter Target IP/Hostname: " SERVER_IP
    if [ -z "$SERVER_IP" ]; then
        echo "Error: Target IP is required."
        exit 1
    fi
    
    read -p "Enable Basic Authentication? [y/N]: " ENABLE_AUTH
    if [[ "$ENABLE_AUTH" =~ ^[Yy]$ ]]; then
        read -p "Enter Username: " USER_NAME
        read -s -p "Enter Password: " PASSWORD
        echo "" # New line
    fi
else
    SERVER_IP=$1
    USER_NAME=$2
    PASSWORD=$3
fi

CONFIG_FILE="/etc/prometheus/prometheus.yml"

# Ensure the script is run with sudo
if [ "$EUID" -ne 0 ]; then
  echo "Please run this script with sudo."
  exit 1
fi

if [ ! -f "$CONFIG_FILE" ]; then
    echo "Prometheus configuration file not found at $CONFIG_FILE"
    exit 1
fi

echo "Adding node $SERVER_IP to $CONFIG_FILE..."

# Build the configuration block
JOB_BLOCK="
  - job_name: 'nodes_$SERVER_IP'
    static_configs:
      - targets: ['$SERVER_IP:9100']"

if [ -n "$USER_NAME" ] && [ -n "$PASSWORD" ]; then
    echo "Applying basic authentication for user: $USER_NAME"
    JOB_BLOCK="$JOB_BLOCK
    basic_auth:
      username: '$USER_NAME'
      password: '$PASSWORD'"
fi

# Append the new job configuration
echo "$JOB_BLOCK" >> "$CONFIG_FILE"

# Restart Prometheus to apply changes
if [ -x "/usr/bin/restart_prometheus" ]; then
    /usr/bin/restart_prometheus
else
    systemctl restart prometheus
fi

echo "Done. node $SERVER_IP added. Prometheus restarted."