Cloudflare Worker - Status Page

Monitor your websites, showcase status including daily history, and get Slack notification whenever your website status changes. Using Cloudflare Workers, CRON Triggers, and KV storage. Check my status page out! 🚀

Pre-requisites

You'll need a Cloudflare Workers account with

• A workers domain set up
• The Workers Bundled subscription $5/mo
  • It works with Workers Free! Check more info on how to run on Workers Free.
• Some websites/APIs to watch 🙂

Also, prepare the following secrets

• Cloudflare API token with Edit Cloudflare Workers permissions
• Slack incoming webhook optional

Getting started

You can either deploy with Cloudflare Deploy Button using GitHub Actions or deploy on your own.

Deploy with Cloudflare Deploy Button

1. Click the button and follow the instructions, you should end up with a clone of this repository

2. Navigate to your new GitHub repository > Settings > Secrets and add the following secrets:

   - Name: CF_API_TOKEN (should be added automatically)
   
   - Name: CF_ACCOUNT_ID (should be added automatically)
   
   - Name: SECRET_SLACK_WEBHOOK_URL (optional)
   - Value: your-slack-webhook-url
   

3. Navigate to the Actions settings in your repository and enable them

4. Edit config.yaml to adjust configuration and list all of your websites/APIs you want to monitor

   settings:
     title: 'Status Page'
     url: 'https://status-page.eidam.dev' # used for Slack messages
     logo: logo-192x192.png # image in ./public/ folder
     daysInHistogram: 90 # number of days you want to display in histogram
     collectResponseTimes: false # experimental feature, enable only for <5 monitors or on paid plans
   
     # configurable texts across the status page
     allmonitorsOperational: 'All Systems Operational'
     notAllmonitorsOperational: 'Not All Systems Operational'
     monitorLabelOperational: 'Operational'
     monitorLabelNotOperational: 'Not Operational'
     monitorLabelNoData: 'No data'
     dayInHistogramNoData: 'No data'
     dayInHistogramOperational: 'All good'
     dayInHistogramNotOperational: 'Some checks failed'
   
   # list of monitors
   monitors:
     - id: workers-cloudflare-com # unique identifier
       name: workers.cloudflare.com
       description: 'You write code. They handle the rest.' # default=empty
       url: 'https://workers.cloudflare.com/' # URL to fetch
       method: GET # default=GET
       expectStatus: 200 # operational status, default=200
       followRedirect: false # should fetch follow redirects, default=false
   

5. Push to main branch to trigger the deployment

6. 🎉

7. (optional) Go to Cloudflare Workers settings and assign custom domain/route

   • e.g. status-page.eidam.dev/* (make sure you include /* as the Worker also serve static files)

8. (optional) Edit wrangler.toml to adjust Worker settings or CRON Trigger schedule, especially if you are on Workers Free plan

Telegram notifications

To enable telegram notifications, you'll need to take a few additional steps.

1. Create a new Bot
2. Set the api token you received when creating the bot as content of the SECRET_TELEGRAM_API_TOKEN secret in your github repository.
3. Send a message to the bot from the telegram account which should receive the alerts (Something more than /start)
4. Get the chat id with curl https://api.telegram.org/bot<YOUR TELEGRAM API TOKEN>/getUpdates | jq '.result[0] .message .chat .id'
5. Set the retrieved chat id in the SECRET_TELEGRAM_CHAT_ID secret variable
6. Redeploy the status page using the github action

Deploy on your own

You can clone the repository yourself and use Wrangler CLI to develop/deploy, extra list of things you need to take care of:

• create KV namespace and add the KV_STATUS_PAGE binding to wrangler.toml
• create Worker secrets (optional)
  • SECRET_SLACK_WEBHOOK_URL

Workers KV free tier

The Workers Free plan includes limited KV usage, but the quota is sufficient for 2-minute checks only

• Change the CRON trigger to 2 minutes interval (crons = ["*/2 * * * *"]) in wrangler.toml

Known issues

• Max 25 monitors to watch in case you are using Slack notifications, due to the limit of subrequests Cloudflare Worker can make 50.

  The plan is to support up to 49 by sending only one Slack notification per scheduled run.

• KV replication lag - You might get Slack notification instantly, however it may take couple of more seconds to see the change on your status page as Cron Triggers are usually running on underutilized quiet hours machines.

• Initial delay (no data) - It takes couple of minutes to schedule and run CRON Triggers for the first time

Future plans

Stay tuned for more features coming in, like leveraging the fact that CRON instances are scheduled around the world during the day so we can monitor the response times. However, we will most probably wait for the Durable Objects to be in open beta as they are better fit to reliably store such info.