IP check using Cloudflare Worker

cloudflare-worker-ip-check.js

export default {
    async fetch(request) {
        const { method, url } = request
        const { pathname } = new URL(url)

        const createResponse = (body, status) => new Response(body, {
            status,
            headers: {
                'Content-Type': 'text/plain; charset=utf-8',
                'Cache-Control': 'no-cache, no-store, must-revalidate',
                'X-Content-Type-Options': 'nosniff',
            },
        })


        if (method !== 'GET') {
            return createResponse('Method Not Allowed', 405)
        }


        if (pathname === '/') {
            const clientIP = request.headers.get('CF-Connecting-IP')
            return createResponse(clientIP, 200)
        }
        if (pathname === '/robots.txt') {
            const robotsTxt = `User-agent: *\nDisallow: /`
            return createResponse(robotsTxt, 200)
        }


        return createResponse('Not Found', 404)
    }
}