This is my first attempt at deploying a Go webservice in Cloudflare Workers. The webservice renders barcodes (Code 39 or Code 128) and QR codes.

This repository is setup to do everything via Docker containers, as I do not want to expose my Mac filesystem to npm.

The Makefile should be enough machinery to get you up and running.

make dev

Then, assuming that works, try browsing to: http://localhost:8787/c128/1234567890

• the first URL path component specifies the render type:
  • 2of5 for non-interleaved 2-of-5 barcodes
  • 2of5i for interleaved 2-of-5 barcodes
  • aztec for compact (4 layer) Aztec codes
  • c39 for Code 39 barcodes
  • c128 for Code 128 barcodes
  • qr for QR codes
• the remainder of the URL path component after the slash specifies the render content

• width specifies width in pixels
• height specifies height in pixels

Note that each format has its own default sizing --- generally, 165x50 for barcodes and 200x200 for QR/Aztec.

Sizes smaller than 50x50 will be rejected.

eg.

• http://localhost:8787/qr/https://github.com/jsleeio/barcodeweb/ (this is broken, as you'll see if you try it; see caveats section at the end of this file)

• http://localhost:8787/qr/hello-world

• http://localhost:8787/qr/hello-world?width=400&height=400

• http://localhost:8787/aztec/https://github.com/jsleeio/barcodeweb/ (this is broken, as you'll see if you try it; see caveats section at the end of this file)

• http://localhost:8787/aztec/hello-world

• http://localhost:8787/c128/123456&height=100

• http://localhost:8787/c39/123456&width=200&height=100

1. create a worker named barcodeweb
2. create a Cloudflare API key using the worker template
3. put some Cloudflare configuration data in files in your $HOME:
   • in $HOME/shell-secrets/tokens/cloudflare/email, put your Cloudflare email address
   • in $HOME/shell-secrets/tokens/cloudflare/api-key, put your Cloudflare API key that you created in step 2
   • in $HOME/shell-secrets/tokens/cloudflare/account, put your Cloudflare account ID that you want to deploy into

The run-wrangler helper can be used for other Cloudflare Workers things if you need to use those also.

make deploy

That should be that!

The Go net/http package tidies up request URLS, including coalescing consecutive slashes, which makes generating QR and Aztec images containing URLs impossible without moving the QR/Aztec content to a query parameter.

Specifically, URLs like https://localhost:8787/qr/https://my.website/ will generate a 301 redirect to https://localhost:8787/qr/https:/my.website/ --- the // has been replaced with /.

I currently don't see a way around this, as it even appears to do it when the // is URL-encoded. More info here: golang/go#21955