Add Documentation for setting up upstream IAMs with Keycloak

[mamy-CS]

Added documentation for setting up upstream IAMs with Keycloak

• Microsoft AD
• Google OAUTH
• Github OAUTH

To do & enhancements

• Openshift v3&v4
• Roles mapping documentation for each IAM

[maia-iyer]

Left initial review. I followed the instructions for both Azure and Github and do not get the desired result. For Azure, it properly redirects me, but I cannot login with a user I need.

For Github, it appears to attempt a redirect, but gives some error encoded in the URL about a redirect mismatch:

...error%3Dredirect_uri_mismatch%26error_description%3DThe%2Bredirect_uri%2BMUST%2Bmatch%2Bthe%2Bregistered%2Bcallback%2BURL%2Bfor%2Bthis%2Bapplication.%26error_uri%3Dhttps%253A%252F%252Fdocs.github.com%252Fapps%252Fmanaging-oauth-apps%252Ftroubleshooting-authorization-request-errors%252F%2523redirect-uri-mismatch...

[maia-iyer]

I retested it, and I was able to get it to work - except Microsoft one requires you to select "Multitenant" so this detail needs to be added I think. I would add the details of a filled in form for each of keycloak and the upstream IDPs so that these details can be explained away

Also having gone through this I'm noticing the keycloak steps are pretty much always the same - maybe we can shorten the documentation. My suggestion would be to

1. put the keycloak documentation at the top
   a. State where the relevant Redirect URI is (with the screen shot)
   b. Tell users to fill in the Client ID and Client Secret after obtaining them from the the desired IDP below
2. For each IDP create a collapsible section for readers to click into.
   a. Talk about how to get to the relevant form to fill in Redirect URI
   b. Show a filled in picture of the form with the important selections

While Keycloak is technically the last step, I think this might be clear enough.

[maia-iyer]

On this step I got it to work, but I also needed to select multitenant option. Add this detail when screenshooting?

[maia-iyer]

This is very clean! So I have a minor nit comment for the lines that go:

> [!TIP]

I think do a sweep through because some of them haven't put the rest of the text on the next line in order to parse properly

I also do not see the TenantID field in Keycloak for Azure. Are you using the example in Tornjak repo or the helm charts? I'm using the example in Tornjak, so maybe it needs to be updated either with the right config. Probably can't remove the example in Tornjak repo to point to helm charts right now because that has the changes for the latest version of Tornjak to work with Keycloak. If you're using the helm charts, maybe make a note at the top about this should be sufficient?

[maia-iyer]

LGTM! Really great documentation!