Allow gradio embeds in colab without share

[aliabid94]

Embeds Gradio apps directly into using colabs output.serve_kernel_port_as_iframe. Had to change default api endpoint name to /run (though /api is still supported for backwards compatibility.).

Note: websockets with queueing are not supported, so will still use sharing in that case.

Example colab: https://colab.research.google.com/drive/1oOyMGV0cxziK_ViSmh0y2c2FxPOHPFMs?usp=sharing

[github-actions]

All the demos for this PR have been deployed at https://huggingface.co/spaces/gradio-pr-deploys/pr-2455-all-demos

[aliabid94]

Still a draft because the colab.html code I copied from your colab @pngwn but I assumed that might not be the final version of that code. feel free to edit this PR directly

[abidlabs]

It looks like we are migrating from "/api" to "/run" as the official API endpoint. Let's make sure to update the "view API" page as well.

Also this is a bit of an edge case but what happens if a user-supplied api_name includes the string "api". Perhaps we can print a warning to users letting them know that their app will not work inside Colab

[aliabid94]

Does colab block any call with a substring "api"? Anyways, even if they create a custom named API, the frontend does not use the names API's, so gradio UI will still work fine.

[abidlabs]

This is really cool stuff @aliabid94 and @pngwn!

I released a new version gradio==3.0.1b123 to test with the latest changes. However, this version is not working for me. Anytime I try to launch an Interface, I get "ValueError: When using queueing in Colab or when localhost is not accessible, a shareable link must be created. Please set share=True." I think I know the culprit (it's the if condition that I commented on above).

In the meantime, I'm testing with gradio==3.0.1b121 which seems to work

[abidlabs]

Tested a bunch of different Gradio demos with gradio==3.0.1b121and generally everything seems to be working! Some feedback:

• When you launch a demo on colab, some text is printed (the URL for localhost, etc.) before the demo overrides the text. The experience is a little disorienting, we should try to leave the text there or hide the text altogether

• If you launch a demo, and have a few minutes of inactivity, the following error happens:

I thought this error only happens if you have queuing enabled, but I experienced with a very simple UI without the demo enabled. We should investigate what's going on here.

• queueing() does not work. You may have fixed it after gradio==3.0.1b121 was released, but this needs to be tested

[pngwn]

This is great. I think most of the frontend code is fine, left a few comments but I can't think of anything else we really need to cover.

[aliabid94]

Okay everything should be fixed!

• Copied logic of internal google.colab.output.serve_kernel_port_as_iframe and modified it to allow iframe permissions
• Window sizes now respect height and width
• File downloads do not respect the port proxying, so implemented something that detects colab, and if so, opens file downloads in a new tab (which works)
• Updated language and comments as suggested

I think it's good to go!

[abidlabs]

LGTM, I can confirm that the issues above have been fixed 🚀 🚀

Made a very small tweak to the printed message to link to the GitHub repo

[freddyaboulton]

What's the right version to test with? 3.0.1b121?

[abidlabs]

What's the right version to test with? 3.0.1b121?

It looks like @aliabid94 modified the original Colab to install from this branch instead of pypi