Description of problem:

As mentioned on the API Documentation :
https://access.redhat.com/documentation/en-us/red_hat_satellite/6.14/html-single/api_guide/index#chap-Red_Hat_Satellite-API_Guide-Using_the_Red_Hat_Satellite_API

You can use the API on Satellite Server via HTTPS on port 443, or on Capsule Server via HTTPS on port 8443.

For the host that is subscribed to Satellite Server or Capsule Server, you can determine the correct port required to access the API from the /etc/rhsm/rhsm.conf file, in the port entry of the [server] section. You can use these values to fully automate your scripts, removing any need to verify which ports to use.

When registering a machine to the capsule , on [server] section the port is 443 which is used to connect to the capsule to obtain subscriptions by Ansible Automation Platform which results in an error :

No subscriptions found
POST api/v2/config/subscriptions/ 400
404 Client Error: Not Found for url: https://[Capsule]:443/katello/api/organizations

By checking the apache conf :

8443 simply forward what ever the request path to the Satellite as below:

1. 1. Proxy rules
      ProxyRequests Off
      ProxyPreserveHost Off
      ProxyPass / https://satellite.redhat.com/ disablereuse=on retry=0
      ProxyPassReverse / https://satellite.redhat.com/

But 443 only forward to certain paths to Satellite. For example: "/rhsm" path

1. 1. Proxy rules
      ProxyRequests Off
      ProxyPreserveHost Off
      ProxyPass /rhsm https://satellite.redhat.com/rhsm disablereuse=on retry=0
      ProxyPassReverse /rhsm https://satellite.redhat.com/rhsm
      ProxyPass /redhat_access https://satellite.redhat.com/redhat_access disablereuse=on retry=0
      ProxyPassReverse /redhat_access https://satellite.redhat.com/redhat_access

Therefore, the katello/api won't work in 443.

Version-Release number of selected component (if applicable):

6.12
6.13
6.14

How reproducible:

100%

Steps to Reproduce:
1. Register a machine to the capsule.
2. Check the port under [server] section.
3. Try to register Ansible Automation Platform machine to the capsule and select subscriptions from the settings -> subscriptions

Actual results:

No subscriptions found
POST api/v2/config/subscriptions/ 400
404 Client Error: Not Found for url: https://[Capsule]:443/katello/api/organizations

Expected results:

To be able to obtain subscription.

Additional info: