server_health_check

#!/bin/bash

# Configuration
SERVICE_URL="http://127.0.0.1:3000"
LOG_FILE="/var/log/nodejs-health.log"
WARNING_FILE="/var/log/nodejs-warnings.log"

# Function to log messages
log_message() {
    local timestamp=$(date '+%Y-%m-%d %H:%M:%S')
    echo "[$timestamp] $1" >> "$LOG_FILE"
}

# Function to log warnings
log_warning() {
    local timestamp=$(date '+%Y-%m-%d %H:%M:%S')
    echo "[$timestamp] WARNING: $1" >> "$WARNING_FILE"
}

# Function to check if systemd service is running
check_systemd_service() {
    systemctl is-active --quiet node-app.service
    return $?
}

# Function to restart the service
restart_service() {
    log_message "Attempting to restart node-app.service..."
    sudo systemctl restart node-app.service
    sleep 5  # Wait for service to restart
    
    if check_systemd_service; then
        log_message "Service successfully restarted"
        return 0
    else
        log_warning "Failed to restart Node.js service - System remains down"
        return 1
    fi
}

# Main health check
main() {
    # Create log files if they don't exist
    touch "$LOG_FILE"
    touch "$WARNING_FILE"
    
    # Check if service is running
    if ! check_systemd_service; then
        log_warning "Node.js service is not running - System crashed"
        restart_service
        exit 1
    fi

    # Make HTTP request to check service
    response=$(curl -s -w "%{http_code}" "$SERVICE_URL" -o /dev/null)
    
    if [ "$response" = "200" ]; then
        log_message "Health check passed - Service is responding normally"
    else
        log_warning "Service is not responding properly (HTTP $response) - System may be crashed"
        restart_service
    fi
}

# Run main function
main