Sure we can add a non-root user, as long as it works well for both vscode and standalone docker env.

I’ve update the PR

For the nightly image, I don’t think we have a keras-nightly.
I think that tf-nighlty Tensorflow image, so GPU version, is a little bit too large just for Keras.

You could transform the postCreateCommand in a Dockefile layer but requirements.txt is out of the Dokerfile context.
If we don’t have a clear knowledge of the breaking change on the Keras ft-nighlty dependency we need to install `tf-nighlty’ wheel every day.
At least you can find a solution to install tf-nightly-cpu to lower this daily overhead when we are on Codespace or on CPU only machine as not all the PRs have a GPU requirements.