Upload files to machines

[S. Sara]

Hi everybody,

I am working on a cockpit plugin. Among some features, I would like to be able to upload some heavy binary files (# 500MB) to remote machines through cockpit web page.
Do you have some advices on how to do this ?
I am not sure the cockpit.file API is suitable for this.
Good job with this software.

Best Regards

S.

[Martin Pitt]

Hello S.,

sorry for the really late reply! Just cleaning up my mailbox, and that was
forgotten.

S. Sara [2019-10-21 15:52 +0000]:
> I am working on a cockpit plugin. Among some features, I would like to be able to upload some heavy binary files (# 500MB) to remote machines through cockpit web page.
> Do you have some advices on how to do this ?

https://github.com/cockpit-project/cockpit/issues/12338 has some details about
this. Indeed this needs documentation and some refinement (Stef recently made
the chunking better), but at least with spawning a process like dd, having that
write the output file, and feeding blocks into it with .input() seems like a
workable solution for now.

It of course would be better if the cockpit.file() API would support sending
the contents in multiple chunks, but cockpit.js doesn't currently do that.

However, the *protocol* [1] does allow it. I. e. you can open a raw channel [2]
with the payload="fsreplace1" type, and feed the data using channel.send() in
multiple blocks. I'm not aware of an existing example there, but that's IMHO
the most elegant and efficient way.

Thanks,

Martin

[1] https://github.com/cockpit-project/cockpit/blob/master/doc/protocol.md#paylo...
[2] https://cockpit-project.org/guide/latest/cockpit-channels.html