Understanding the Celest Cloud Limitations

[starklord]

Hi i want to understand what can we do inside the celest cloud. Are there specifications or any doc about that?
Im new with the "Cloud Functions" concept, i come from the traditionals VPS virtual private servers where you can for example read write files. So,
Wat can and can´t do inside the celest cloud or inside a celest function?
For example if i use path_provider and run "celest deploy" this give me an error:
Failed to deploy project. Please contact the Celest team and reference deployment ID: deployment_01htfvcf0eetahaf9qhwg93ttp

[dnys1]

Hi @starklord, yes good point. Celest is going for more of a serverless model at the moment, which I definitely need to document better. Every function has a 500MB scratch space located at /tmp which can be used for processing files, but is not guaranteed to persist between executions.

Regarding your deployment, I'm not seeing an error for that deployment in my logs 🤔 It's showing as successful on my end, oddly. It might be because of path_provider depending on Flutter--I will try to replicate the error locally.

[dnys1]

Does celest start work?

[dnys1]

Okay, yeah I'm very certain it's because of path_provider. The transitive dependency on Flutter pulls in the dart:ui library, which is not available in server contexts. This issue has been on my radar for a while now. I'm happy to dig more into it and see what a fix could be.

[dnys1]

In the meantime, unfortunately, it's required to use packages that do not depend on Flutter.

[starklord]

Does celest start work?
celest start doesnt work if i import the path_provider library in my function file.
PS D:\workspaces\flutter\celest_app2> celest start
⠦ Starting Celest... (6.9s)Project has errors. Please fix them and save the corresponding files.

Okay, yeah I'm very certain it's because of path_provider. The transitive dependency on Flutter pulls in the dart:ui library, which is not available in server contexts. This issue has been on my radar for a while now. I'm happy to dig more into it and see what a fix could be.
Ah ok i see now, its reasonable.

In the meantime, unfortunately, it's required to use packages that do not depend on Flutter.
What about the dart:io library ? i have this error reading/writing files(and i dont know if this is for any streaming) and this happens in local and production environment
server dateTime: #0 _checkForErrorResponse (dart:io/common.dart:55:9)
...

my code is just as simple as:

Future createFile(String fileName) async {
try {
var file = File("filenew.txt");
var text = await file.readAsString();
return text;
} catch (e, s) {
log(s.toString());
return s.toString();
}
}

[dnys1]

@starklord Could it be the file does not exist?

The method says createFile but if filenew.txt does not exist already, then reading it is expected to throw an error.

[starklord]

Ah ok it can be possible the file does not exist because you told me the files created are temporary isnt it?
Oky doky ill keep making more testings :3 thank you so much for this product. Its getting better and better!

[dnys1]

I appreciate it!

Yes, the filesystem support is something that needs some thought and care. I've created a new issue to track this! #102