Create a free go-link server “on edge” using Cloudflare Worker KV

2021-06-06T00:00:00+06:00

Among quite a few ways to implement a go-link server (i.e., url-forwarder, short-url server, etc.), I’m going to show you how to use free-tier Cloudflare Worker (& KV) to create an in-house, on-edge, no-webserver go-link server.

For example, the short-link for this article is go.kmonsoor.com/golink-kv

/latest (by which I mean go.yourdomain.co/latest) may point to https://www.yourcompany.com/about/news which is a public page
/hr-help may point to https://www.company-internal.com/long-link/hr/contact.html, which is company’s internal human-resources help portal
/cnypromo may point to https://shop.yourcompany.com/sales/promotions/?marketing-promo=2021-cny which is a temporary sales promotions page targeting the shoppers during the Chinese new year of 2021.

Please note that using the setup and the code below, it’ll be possible to resolve short-links via a single sub-domain, e.g., go.your-domain.co. However, it’s possible (with some modification of the code) to resolve/redirect via any number of domains (your own, of course) towards any other public or private URL, and all sorts of novelties. However, for brevity’s sake, I will discuss the first one, a single sub-domain usecase.

To set up a go-link server or short-URL resolver via a proper KV+Worker combination, we’ll go through these steps:

Pre-requisites
Create the short-link map as a KV
Mapping a KV to a Worker variable
Handling a route with webworker
Create the Worker
Pointing a DNS record to the Worker
Next step
Related

Pre-requisites¶

The DNS resolver for the root domain (in the example below, kmonsoor.com) needs to be Cloudflare. Because the core of the solution, the “worker”, runs on the nearest (from the user) edge of Cloudflare using a standard KV (“key, value”) list.
Write permission to the DNS configuration as you’d need to add a new AAAA DNS record.
Some knowledge of Javascript(ES6), as we are going to write the “worker” in that language.

Create the short-link map as a KV¶

We’ll start the setup by creating the short-link map, the list between the short-link segments that you (or someone in your org) define, and the actual URLs they need to point to.

Find the KV stuff in the Workers section. From the screenshot, please ignore the “Route” section for now.

you’d need to create a Worker KV “Namespace”. Name the namespace as you seem fit. I named it REDIRECTS (in all caps just as a convention, not required).
List the short links & their respective target URLs. From the examples in the intro, the keys latest, hr-help, cnypromo etc. would be in as the “key”, and the target full links as the respective “value”.
Remember NOT to start the short part with ‘/’. It’ll be taken care of in the code.

Once you’ve listed all your desired (short-link, target-link) combinations, now we have a KV on Cloudflare. However, it’s not referencable from your Worker code, not yet. Hence the next step.

Mapping a KV to a Worker variable¶

Now, we will map the previously created KV to a variable that can be referenced from our Worker code. Please note that though I used different names, it can be the same as well. Also, note that multiple Workers can access a single KV, and vice versa is also true; a single Worker can reference multiple KVs.

Handling a route with webworker¶

Create the Worker¶

Now, we will write Worker-code that runs on V8 runtime on the nearest (from the requesting user) “edge” location of Cloudflare, to execute the code and deliver the result(s) to the user. In this case, that would be to redirect user-requested address to the mapped one (by you, in the KV namespace above).

The code editor looks like this:

If you rather prefer to copy-paste, please feel free to do it from the below GitHub Gist.

Once done, it should look like …

Pointing a DNS record to the Worker¶

Finally, we need to point a DNS record that’ll redirect all requests to your re-soutign sub-domain (e.g. go.your-domain.com) to the Cloudflare Worker that we just created.

According to the Cloudflare docs, the DNNS record must be an AAAA record, pointing to the IPv6 address 100::. The “Name” here is the “sub-domain” part of your choice, which is better be short, to rightfully serve our goal here.

Voila ! Now, test some of the short-urls that you’ve mapped via the KV. Enjoy ! Watch out for the target usage though. Here’s the limit.

I think you’ll be fine, unless you’re some celebrity ;)

Next step¶

As the next step, I’m thinking to create a generic Go/Link resolver browser extension. Then, someone can set their own default domain or company domain of choice as short-domain host. In that case, entering just go/hr-help on the browser will take to https://www.company-internal.com/.../hr/contact.html that we have discussed at the beginning (remember the example case of an internal human resources help portal?).

If you want to do this url-direction on your server, but only using webserver, try this: Personal short-link server using only Caddyserver

If you find this post helpful, you can show your support through Patreon or by buying me a coffee. Thanks!

TL;DR what cloud provider to use in 2021

2021-05-22T00:00:00+06:00

The sheer number of combinations a company can choose from the cloud providers and their product suites is mind-boggling. Hence, I decided to break it down in a concise form for the busy C-suite executives.

According to my little experiences and humble opinion, I suggest …

➤ If your company is a small SaaS shop with 10-ish engineers, stick with DigitalOcean, Linode, OVH, etc., which are best known as cloud “instance” providers.
Think McDonald’s; reliable, cheapest, fast, but you won’t take your date there.
Budget: 💰

➤ If you want a whole cloud experience (e.g., VPC, firewall, WAF, etc., on the menu), start with Google Cloud, then try AWS later.
Google Cloud would be the quickest to grasp the cloud concepts and get going. The UI of the AWS console is a bit messy compared to GCP; it just takes more time to get a proper grip.
Imagine them as full-course, Michelin-star restaurants. However, the product names are so abstract that they need a full-sized chart for that. ;) Budget: 💰💰💰

➤ Are you planning to set up a million-dollar infra for a billion-dollar company? Go for some GCP+AWS multi-cloud setup. You gonna get rebates from both on the scale of hundreds of thousands of dollars. And Microsoft Azure gonna offer you some million-$ free-tier, hoping to get the company hooked on Azure. :D Budget: 💰💰

➤ On the other hand, if you run a govt agency or a company where wearing suits is the mainstream, Microsoft Azure is your best bet.
A bunch of consultancy companies to choose from; you need to just approve the budget, you get the things to get up & running but miss the deadline by months, if not years. But there’d be no need for hiring more smarter ppl than that you already have. Budget: 💰💰💸

Need an even more comprehensive guide? Gotcha, fam …

CTO: we're having hard time choosing a cloud provider
…
“say no more, fam, I gotcha …” pic.twitter.com/hR3rMruWWi
— Khaled Monsoor ✨ (@kmonsoor) May 22, 2021

PS This post is inspired by a LinkedIn post of mine where I shared about my short experience with the Microsoft Azure DevOps suite

I think ... - cloud