Add Docker instructions in tensorboard-in-notebooks

[brunapinos]

Hi!
As described in #1952, it was necessary to add the information to expose the TensorBoard port when running the notebook using TensorFlow docker image. So, I added a paragraph in tensorboard-in-notebooks file, explaining the usage with docker, in Setup section:

[review-notebook-app]

Check out this pull request on ReviewNB: https://app.reviewnb.com/tensorflow/tensorboard/pull/2336

Visit www.reviewnb.com to know how we simplify your Jupyter Notebook workflows.

[nfelt]

@brunapinos Thanks for the contribution! ReviewNB can't render the diff, is it possible the new .ipynb file isn't quite formatted right? Also, is there a chance you might be able to reduce the size of the diff in the raw .ipynb? It looks like a lot of extra lines were moved around (indentation changes, re-ordering json fields) even though I believe content-wise you just added the one paragraph.

[brunapinos]

@nfelt Thanks for the review! I'll reduce it!

[brunapinos]

@nfelt So, I had to give a push force to commit my changes with Colab. I don't know if it was the best way to do that. If you want, I can open another PR to commit these changes.

[nfelt]

Thanks for reducing the diff! There are still some places where it seems like the changes are unrelated to the new content:

• cell_type fields have been re-ordered
• execution_count fields have been reset to 0
• embedded images have changed to use fully-qualified URLs rather than relative paths (which won't work on the documentation site that we use for tensorflow.org/tensorboard, and also doesn't render in the ReviewNB view any more)

Would you mind reverting those changes so we keep this focused on just the new paragraph?

[googlebot]

So there's good news and bad news.

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[googlebot]

CLAs look good, thanks!

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[brunapinos]

Now the diff is only referred to the paragraph added!

[wchargin]

Diff looks much better; thanks!

[wchargin]

This doesn’t seem to work for me—when I use %tensorboard in the
Jupyter notebook, I still get “localhost refused to connect”. It works
if I change -p 6006 to -p 6006:6006. Can/should we use that instead?

(I’m not super familiar with Docker, so if I’m missing something then
please fill me in!)

[brunapinos]

Sorry, it was really missing :6006 in command. I've already fixed.

[wchargin]

Looks good, then—thanks a bunch!