RHEL subscription

A Red Hat Enterprise Linux (RHEL) subscription is required because RHEL provides official repositories for software packages, security updates, and support. Without an active subscription, you will not have access to these repositories, meaning you cannot install or update critical packages like Docker or Podman from official Red Hat sources.

Why to Subscribe to RHEL

A valid RHEL subscription ensures:

Access to Official Repositories – Required to install Docker, Podman, and other necessary packages.
Security and Bug Fix Updates – Ensures your system receives the latest security patches and fixes.
Technical Support – Provides access to Red Hat’s support services.

If your system is not subscribed, package installation may fail with errors like "This system is not registered" or "No available repositories" when trying to install software.

After installing RHEL, you must manually register your system with Red Hat Subscription Manager.
Some enterprise environments may provide automatic registration through Satellite Server or Red Hat Cloud Access if configured by your organization.
If you are using a free developer version (RHEL Developer Subscription), you still need to activate it through your Red Hat account.

How to Subscribe to RHEL

Follow these steps to register and subscribe your system:

Check Subscription Status

Run the following command to verify if your system is already subscribed:
```
sudo subscription-manager status
```
- If the system is subscribed, you will see "Overall Status: Current".
- If it is not subscribed, proceed with the following steps.
Register Your System with Red Hat

Run this command and enter your Red Hat account credentials when prompted:
```
sudo subscription-manager register
```
If you do not have an account, create one at Red Hat Customer Portal.
Attach a Subscription

After registering, attach an available subscription:
```
sudo subscription-manager attach --auto
```
If you have multiple available subscriptions, list them using:
```
sudo subscription-manager list --available
```
Then manually attach a specific subscription using:
```
sudo subscription-manager attach --pool=<POOL_ID>
```
Enable Required Repositories

Depending on your RHEL version, enable the necessary repositories:
- For RHEL 7:
```
sudo subscription-manager repos --enable=rhel-7-server-extras-rpms
```
- For RHEL 8:
```
sudo subscription-manager repos --enable=rhel-8-appstream-rpms
```
- For RHEL 9:
```
sudo subscription-manager repos --enable=rhel-9-appstream-rpms
```
Verify Subscription and Repositories

Ensure your subscription and repositories are properly set up:
```
sudo subscription-manager list --consumed
sudo subscription-manager repos --list-enabled
```

Once your system is subscribed, you can proceed with installing Docker or Podman without issues.