Documenting the behavior of the upload_file function

[gemblerz]

plugin.upload_file() uploads user-specified files to cloud. It is unclear how this works in user application container. We will need to describe the behavior of the function so that users know what to expect from this function.

One question raised on this topic was "I am sending files (~200MB) using the function. When is safe for the application to exit, and the system terminates the application container?" The answer is that the upload_file function copies the file to a permanent storage before returning. So, it is safe to terminate user application after the function returns.

I suggest adding a bit of information about this behavior in the doc.

[RBhupi]

Hi Yongho,

Good to see this issue popping up.
I am using this from last 3 years and one thing that always get me is the default behavior of deleting file. I just encounter it during my test on the node. This is too dangerous and default behavior should be what is expected of the function named plugin.upload_file() i.e. to upload the file. Nothing more!
I think it can cause more harm to keep it this way than to change the default behavior, especially now that we have access to the node data. Documenting this well will not reduce the dangers.

Bhupendra

[gemblerz]

Hello @RBhupi. Thank you for sharing your opinion.

I agree. Given that some applications might want to upload files from a persistent directory and they do not want those files deleted from the persistent directory, we should probably change the behavior and not delete files after upload.

This behavior change wouldn't affect the current use because applications using temporal storage, like files in an application container, will be cleaned up by the system when the application exits.

I suggest changing the function to have a boolean argument "remove_on_success" to remove the file upon success of uploading. The default should be false.