As a first time user I want getting started documentation on API authentication

Author: @quba42 (quba42)

Redmine Issue: 9197, https://pulp.plan.io/issues/9197

I just installed a brand new from scratch pulp instance using the pulp installer.

I used the example playbook (modifying only the list of plugins I wanted), as a first time user might.

The installation was successful, and I can get the API status as follows (yeah!):

https --verify=no get warehouse.infra.dev.atix/pulp/api/v3/status/

All other API endpoints return 403 Forbidden "Authentication credentials were not provided."

The getting started installer documentation contain no further guidance on what authentication my default installation expects: https://docs.pulpproject.org/pulp_installer/quickstart/

In pulpcore I can find general installation, but nothing relating to my simple/default/quick start installation: https://docs.pulpproject.org/pulpcore/authentication/index.html

My basic user expectation that the quickstart/getting started installation instructions will get me as far as a tiny initial usage example is not met. 😉

Start with the pulp_installer quickstart and pulpcore authentication documentation linked in the issue. Identify the default authentication expected by a fresh installer-based installation and document a small authenticated API example. Done means a first-time user can proceed beyond the status endpoint using the getting-started guidance.