CloudFlare Workers Status API

README.md

CloudFlare Workers as Status API

In most case, the CloudFlare SLA is greater than our server. So, we can use it as a simple uptime checker.

Usage

1. Deploy index.js to your CloudFlare Workers, and bind KV which you save the status.
2. Add updater.rb to your server, and setup cron job to run it
3. Get node status on any static page with https://your-worker.workers.dev/?node[]=name to fetch node status
4. Build some script to check timestamp and verify uptime status

index.js

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

/**
 * Fetch and log a request
 * @param {Request} request
 */
async function handleRequest(request) {
    // Response as JSON
    let responseInit = {
        status: 200,
        headers: {
            'Content-Type': 'application/json;charset=UTF-8'
        }
    }

    // Find all request nodes
    let url = new URL(request.url)
    let nodes = url.searchParams.getAll('node[]')
    let status = await getAllNodeStatus(nodes);
    
    return new Response(JSON.stringify(status), responseInit)
}

// Read nodes status from KV
async function getAllNodeStatus(nodes) {
    let status = {};
    await Promise.all(nodes.map(async (node) => {
        var nodeStatus = await Status.get(node, 'json');
        if (nodeStatus) {
            status[node] = nodeStatus
        }
    }));
    return status;
}

updater.rb

# frozen_string_literal: true

require 'net/http'

class Updater
  attr_reader :hostname

  API = 'https://api.cloudflare.com/client/%<version>s/accounts'
  ENDPOINT = '/%<account>s/storage/kv/namespaces/%<namespace>s/values/%<node>s'

  def initialize
    @node_name = ENV['NODE_NAME'] || Socket.gethostname
  end

  def update!
    Net::HTTP.start(uri.host, uri.port, use_ssl: ssl?) do |http|
      http.request request
    end
  end

  def request
    request = Net::HTTP::Put.new(uri)
    request['X-Auth-Email'] = ENV['CF_EMAIL']
    request['X-Auth-Key'] = ENV['CF_TOKEN']
    request.body = body.to_json
    request
  end

  def ssl?
    uri.scheme == 'https'
  end

  def uri
    @uri ||=
      URI(format("#{API}#{ENDPOINT}", options))
  end

  def options
    {
      version: 'v4',
      account: ENV['CF_ACCOUNT_ID'],
      namespace: ENV['CF_NAMESPACE_ID'],
      node: @node_name
    }
  end

  def body
    {
      status: :online,
      timestamp: Time.now.to_i
    }
  end
end