Adds Embedded Cluster lab

[crdant]

TL;DR

Provides "Delivering Your Application as a Kubernetes Appliance" lab

Details

Implements a lab named "Delivering Your Application as a Kubernetes
Appliance" that shows how to package and install with Slackernews with the
Replicated Embedded Cluster.

The lab takes the user through iteratively building the Embedded Cluster
implementation of Slackernews based on the Helm chart. Once they have a
working implementation they install it as a customer then review the new
instance in the Vendor Portal.

[crdant]

Test the lab here:

https://play.instruqt.com/embed/replicated/tracks/delivering-as-an-appliance?token=em_lUZdcv0LrF6alIa3

[crdant]

@ajp-io @paigecalvert I'd really like to get this PR squared away before I start my vacation tomorrow evening. Any chance one of you can give it at approve?

Alternatively, @xavpaice or @chris-sanders , could I entice you into doing a review?

[paigecalvert]

Just did another end-to-end run through @crdant and got stuck at the install step with the following error:

Looks like it wasn't wanting to download the install assets. I tried copy and pasting the commands from the lab and directly from the Vendor Portal just to make sure there wasn't some discrepancy there, but they look to be the same.

This of course meant that I couldn't test the last step in the Admin Console, but all the content looked good to me otherwise.

[ajp-io]

I've gotten stuck each time I've tried, so I haven't made it all the way through yet. But I will try to finish it today.

[crdant]

Just did another end-to-end run through @crdant and got stuck at the install step with the following error:

Looks like it wasn't wanting to download the install assets. I tried copy and pasting the commands from the lab and directly from the Vendor Portal just to make sure there wasn't some discrepancy there, but they look to be the same.

This of course meant that I couldn't test the last step in the Admin Console, but all the content looked good to me otherwise.

@paigecalvert This generally means there was an error in the release or the download, if you see it again can you try running cat slackernews*.tgz and see what is shows? If it shows you a warning about a binary file then you can cancel, otherwise post the content here.

[crdant]

@ajp-io and @paigecalvert I found it! There was a --chart flag (and reference to the chart) where there should have been a --yaml-dir. Fix is testing now.

[crdant]

That was it. Fix is live and in this PR.

[crdant]

@ajp-io @paigecalvert You should be able to skip to "Using the Configuration to Install and Upgrade" and complete the lab from there. That's where the bad instruction was.

[paigecalvert]

Sounds good @crdant I'll do that today

[crdant]

Thank you @paigecalvert

[paigecalvert]

@crdant Success! Made it through the rest of the lab without errors. Just added a couple suggestions for some mismatches I saw with the config screen fields and the lab content