Cloudflare Developers•2y ago

use fetch() function

Alisson AcioliOP•2/27/24, 5:50 PM

await fetch('https://example.com/', {
method: 'POST',
body: ''
})

Alisson AcioliOP•2/27/24, 5:51 PM

https://developer.mozilla.org/pt-BR/docs/Web/API/fetch

MDN Web Docs

fetch() - APIs da Web | MDN

O método global fetch() inicia o processo de busca de um recurso da rede, retornando uma promessa que é cumprida assim que a resposta estiver disponível.

AAlisson Acioli use fetch() function

Electric•2/27/24, 5:56 PM

yea I do that

Cyb3r-Jak3•2/27/24, 5:57 PM

That error typically means a package you are using is using the XMLHTTPRequest method. You will need to patch the package to use fetch or find a different package.

CCyb3r-Jak3 That error typically means a package you are using is using the XMLHTTPRequest m...

Electric•2/27/24, 5:58 PM

oh ok

Electric•2/27/24, 5:58 PM

what about these errors?

Electric•2/27/24, 5:59 PM

(trying to use express.js)

Unsmart•2/27/24, 5:59 PM

Express does not work on workers. You can use something like hono: https://hono.dev/ for a similar experience, used a lot here

UUnsmart Express does not work on workers. You can use something like hono: <https://hono...

Electric•2/27/24, 6:08 PM

can I use dotenv on it as well?

Electric•2/27/24, 6:08 PM

or does that not work

Unsmart•2/27/24, 6:08 PM

You would just use a .dev.vars file instead

Unsmart•2/27/24, 6:09 PM

and theres no

process.env

process.env

you get it from the env passed into the request

EElectric what about these errors?

Alisson AcioliOP•2/27/24, 6:09 PM

If your use of express is for routes, in workers you can work with itty-router where you can create routes, middleware, etc. Workers, for security reasons, limit many things that exist in large libraries, so there will be cases that you will have to get around by looking for others.

Alisson AcioliOP•2/27/24, 6:09 PM

https://github.com/kwhitley/itty-router

JoeDoe•2/27/24, 9:07 PM

Does CF offer a service where I can have a script running all the time that saves data into a D1 database?

JJoeDoe Does CF offer a service where I can have a script running all the time that save...

Hello, I’m Allie!•2/27/24, 9:08 PM

What would trigger the writes?

Hello, I’m Allie!•2/27/24, 9:08 PM

Or, what would you be writing?

HHello, I’m Allie!What would trigger the writes?

JoeDoe•2/27/24, 9:12 PM

hmm, something like this
infinite loop(){
check for data()
if fresh data -> saveToDB()
sleep 5 seconds
}

JJoeDoe hmm, something like this infinite loop(){ check for data() if fresh ...

Hello, I’m Allie!•2/27/24, 9:12 PM

That could probably be a Durable Object with an Alarm

JoeDoe•2/27/24, 9:12 PM

or like a node script

Hello, I’m Allie!•2/27/24, 9:13 PM

You wouldn’t be guaranteed that it is constantly running, but that is to your benefit

JoeDoe•2/27/24, 9:13 PM

something that can run node all the time

Hello, I’m Allie!•2/27/24, 9:13 PM

Since in between the five seconds you aren’t doing anything

JJoeDoe something that can run node all the time

Hello, I’m Allie!•2/27/24, 9:13 PM

Cloudflare doesn’t have any Node-hosting capabilities. Workers is somewhat compatible with Node, but it doesn’t have anything long-running

HHello, I’m Allie!Cloudflare doesn’t have any Node-hosting capabilities. Workers is *somewhat* com...

JoeDoe•2/27/24, 9:14 PM

actually, now that I think, it doesn't need to be long running

JoeDoe•2/27/24, 9:14 PM

can be like a cron job

JoeDoe•2/27/24, 9:14 PM

run->execute->terminate

JJoeDoe actually, now that I think, it doesn't need to be long running

Hello, I’m Allie!•2/27/24, 9:15 PM

Yeah, so if you need 5 second granularity, I would probably go with https://developers.cloudflare.com/durable-objects/api/alarms/#alarms

Cloudflare Docs

Alarms · Cloudflare Durable Objects docs

Durable Objects alarms allow you to schedule the Durable Object to be woken up at a time in the future. When the alarm’s scheduled time comes, the …

JoeDoe•2/27/24, 9:15 PM

doesn't need to be so 'real time'

JoeDoe•2/27/24, 9:15 PM

can be 1min or even 10

JJoeDoe doesn't need to be so 'real time'

Hello, I’m Allie!•2/27/24, 9:17 PM

Then you can go https://developers.cloudflare.com/workers/configuration/cron-triggers/

Cloudflare Docs

Cron Triggers · Cloudflare Workers docs

Enable your Worker to be executed on a schedule.

JoeDoe•2/27/24, 9:21 PM

https://tenor.com/view/whos-awesome-reaction-you-are-you-are-awesome-pointing-gif-15769676

Tenor

CMCDragonkai•2/28/24, 6:22 AM

If I use custom_domain = truecustom_domain = true, but I also want to override the routes using --routes--routes would this work? How do I also specify that we are doing a custom domain on the command line during

wrangler deploy

wrangler deploy

Old Man Maker•2/28/24, 7:17 AM

Hey - not sure if I am missing something, but it is entirely unhelpful to have a sub domain applied to an R2 bucket, yet that sub domain does not appear in the DNS records. Am I missing something here?

AnotherAlex•2/28/24, 11:48 AM

Hello. I’ve been seeing high WorkerCPUTime’s in logs (about 1 second) and was wondering what additional profiling we could do to understand why this is occurring. Our logs show that the fetch function run by the worker is reporting significantly lower run time. We also know the high time occurs at the first request to a new instance. Any suggestions?

kian•2/28/24, 12:09 PM

If it’s always the first request then it sounds like something in the global scope of the Worker

vakno•2/28/24, 12:12 PM

Is it possible to run more than one worker with a worker? I have a parent worker that has service bindings with two child worker that change HTML responses. I want changes that these 2 workers make all applied to the parent worker ( that has a trigger url ). I cant seem to figure out how to combine responses.

OOld Man Maker Hey - not sure if I am missing something, but it is entirely unhelpful to have a...

Cyb3r-Jak3•2/28/24, 12:53 PM

It should appear. I believe it’s at the end of the DNS records because it’s a Cloudflare one and not a standard one.

Kkian If it’s always the first request then it sounds like something in the global sco...

AnotherAlex•2/28/24, 3:16 PM

Thanks. That’s what I originally thought but I can’t find anything in the code that should do that. Anything that needs setting up on first request is done inside fetch, as it requires env vars. Is the Date.now() time at the start of fetch function accurate? I know it only updates on I/O operations but not sure if “fetch has just been called” is one.

kian•2/28/24, 3:20 PM

It'll be pretty accurate, yeah.

Rasel Rana Rocky•2/28/24, 3:36 PM

Hi, I hope it's not too dumb question.
I see that CF workers has a limit of maximum 6 outgoing requests simultaneously.
So, if somehow a single worker gets more than 6 simultaneous requests and I call auth service using

fetch()

fetch()

from the worker, then the requests above the limit will start failing?
I'm decoupling everything into multiple microservices and each request might make more than 1~15 requests to other services, both internal and external.

kian•2/28/24, 3:40 PM

It's 6 outgoing subrequests per incoming request.

kian•2/28/24, 3:41 PM

If you have 10 people hitting the same Worker, each one of those Worker invocations can make 6 outgoing subrequests concurrently.

Rasel Rana Rocky•2/28/24, 3:45 PM

Ah that makes more sense. Thanks

JoeDoe•2/28/24, 4:50 PM

Lets say I use a cron to trigger a script to run, and this script runs a long time, and then another cron triggers the same script, how can I prevent the same script from running at the same time?

JJoeDoe Lets say I use a cron to trigger a script to run, and this script runs a long ti...

Devon•2/28/24, 4:55 PM

setup locks in a persisent store (KV, D1, Durable, whatever meets your usecase needs best).

JoeDoe•2/28/24, 9:29 PM

So all workers start with the fetch() function and thats it?

JJoeDoe So all workers start with the fetch() function and thats it?

Chaika•2/28/24, 9:33 PM

The fetch function/handler is just one of (although the most common) Workers handlers, which is ran on every request to the Worker: https://developers.cloudflare.com/workers/runtime-apis/handlers/fetch/

Cloudflare Docs

Fetch Handler · Cloudflare Workers docs

Incoming HTTP requests to a Worker are passed to the fetch() handler as a request object. To respond to the request with a response, return a Response …

use fetch() function

Similar Threads

Similar Threads

Similar Threads