Add Keycloak Plugin

[PatAKnight]

Story

• As a user, I wish to be able to use Keycloak Authentication and the Keycloak Plugin within the Backstage Showcase app.

Description

• Keycloak is an identity and access management tool. The purpose of this story is to add the Keycloak plugin to the Backstage Showcase app. In addition to adding the Keycloak plugin, we will begin the implementation of authentication starting with a login page.

ACs

• Add the Keycloak plugin to the Backstage Showcase app
• Able to sign into Backstage Showcase app using an account created within Keycloak
• Visualize the users and groups that were created within Keycloak in the Backstage Showcase Catalog
• Document the Keycloak specific process for deployment

Additional Notes

• None