https://github.com/Davie3/mikrotik-cloudflare-iplist/blob/main/automation/cloudflare_ips.py

mikrotik-cloudflare-ips.js

const cloudflareIpURLv4 = 'https://www.cloudflare.com/ips-v4'
const cloudflareIpURLv6 = 'https://www.cloudflare.com/ips-v6'

addEventListener('fetch', (event) => {
  return event.respondWith(handleRequest())
})

/**
 *
 * @param url
 */
async function handleRequest (url = cloudflareIpURLv4) {
  const response = await fetch(url)
  const text = await gatherResponse(response)

  const result = createRules({
    url,
    source: text
  })

  return new Response(result)
}

/**
 * gatherResponse awaits and returns a response body as a string.
 * Use await gatherResponse(..) in an async function to get the response body
 * @param {Response} response
 */
async function gatherResponse (response) {
  const { headers } = response
  const contentType = headers.get('content-type') || ''
  if (contentType.includes('application/json')) {
    return JSON.stringify(await response.json())
  }
  if (contentType.includes('application/text')) {
    return await response.text()
  }
  if (contentType.includes('text/html')) {
    return await response.text()
  }

  return await response.text()
}

/**
 *
 * @param root0
 * @param root0.url
 * @param root0.source
 * @param root0.listNameV6
 * @param root0.listNameV4
 */
function createRules ({
  url,
  source,
  listNameV4 = 'cloudflare-ips',
  listNameV6 = 'cloudflare-ips-v6'
}) {
  let result = ''

  const isV6 = url.toLowerCase().includes('v6')
  const listName = isV6 ? listNameV6 : listNameV4
  const addresses = source.split('\n')

  addresses.forEach((address) => {
    if (isV6) {
      result += '/ipv6'
    } else {
      result += '/ip'
    }

    result += ` firewall address-list add list=${listName} address=${address}\n`
  })

  return result
}