Code powers foobar.rustymagnet.xyz.

• Cloudflare Worker
• Learnings
  • Time
  • Testing
  • Secrets
  • Environment
  • Deploy
  • Debug
  • Workflows
• Architecture
  • End-2-End deployment workflow
  • Design choices

Careful using Date outside a route. Your dev machine will work as expected but the Cloudflare Worker won't.

let epochDatee = Date.now();  // always zero / `1970-01-01` 

addEventListener("fetch", event => {
    let localDate = Date.now(); // expected time and date
})

Still, Cloudflare tests only worked with "vitest": "^2.0.5" as written here. If you upgraded, all the tests failed.

The lock file will get out of sync if you don't use the --save-exact:

npm install vitest@2.0.5 --save-dev --save-exact

Testing required "cloudflare:test" to access environment variables in tests:

import { env } from "cloudflare:test";

it("/carpark ok", async () => {
    const res = await app.request("/carpark", {}, env);
    expect(res.status).toBe(200);
});

Local code uses a .dev.vars to read secret environment variables. The normal .env file is used by Cloudflare code.

Environment specific values can be set in the wrangler.toml file as below; these can be source controlled safely as these are overridden locally by the .devs.vars ( local tests ) and production secrets.

[env.testing.vars]
  SECURITY_HEADER_NAME = "X-Header"
  SECRET_KEY = "dummy"
  ENVIRONMENT = "TESTING"

The environment setting can be fed to vitest: wrangler: { configPath: "./wrangler.toml", environment: "testing" }

[!INFO] Cloudflare suggest here treating your wrangler.toml file as the source of truth for your Worker configuration.

console.log() output is available. Use the tail command in the cli tool. This also outputs Cloudflare added headers like cf-ipcountry, asn, ray-id, True IP.

wrangler tail foo

When errors happened inside a Worker, the output to the console was limited:

[ERROR] Uncaught (async) Error: internal error

But the logs helped:

Logs were written to "/<home>/.wrangler/logs/wrangler-2024-11-16.log"
DNS lookup failed.

You could start a backend workflow using a workflow; this was written using QStash from Upstash.

To test it locally, ngrok was used to route all of the Worker requests via ngrok. So you no longer went to localhost:8787/carpark. Instead you used: https://abcd.ngrok-free.app/carpark

# start ngrok
ngrok http localhost:3001 --log=stdout

# set local environment .dev.vars
QSTASH_TOKEN="xxxx"
UPSTASH_WORKFLOW_URL="https://abcd.ngrok-free.app"

# inspect state of requests or local tunnelling
http://localhost:4040/inspect/http
http://localhost:4040/status

sequenceDiagram

   participant Engineer
   participant GitHub
   participant CircleCI
   participant Cloudflare
   Engineer->>GitHub: code change
   GitHub->>CircleCI: assess change before deploying
   CircleCI->>CircleCI: set up Cloudflare's Wranger cli tool
   CircleCI->>CircleCI: Lint code
   CircleCI->>CircleCI: Test code 
   CircleCI->>Cloudflare: Wrangler cli uploads code change to Cloudflare with the deploy flag

• Started on itty-router. But docs and testing were clearer with Hono.
• The app used Grouping of routers to slim down code into discrete files. Link here.
• Local dev connects to ngrox tunnelling.
• Setting the ENVIRONMENT variable needs to be handled; a great article here
• A Boilerplate on structuring project.
• The JWT work was based these helpers.