2. Tools and Applications for Subscription Management

All Red Hat Enterprise Linux subscriptions automatically include some tools for managing the subscription configuration:
  • Red Hat Subscription Manager client tools to manage local systems
  • Customer Portal Subscription Management to manage systems and subscription application organizations for a single account globally through the Customer Portal
  • Subscription Asset Manager to install an on-premise subscription service
The diversity of tools allows administrators to create a workflow that fits both the business and infrastructure demands of their organization. Since all of these elements are relatively independent of one another, that opens a lot of different potential configuration and deployment scenarios.

2.1. Local System Tools (Red Hat Subscription Manager)

Both registration and subscriptions are managed on the local system through UI and CLI tools called Red Hat Subscription Manager. The Subscription Manager tracks and displays what subscriptions are available to the local system and what subscriptions have been consumed by the local system. The Subscription Manager works as a conduit back to the subscription service to synchronize changes like available product quantities or subscription expiration and renewals.

Note

The Red Hat Subscription Manager tools are always run as root because of the nature of the changes to the system. However, Red Hat Subscription Manager connects to the subscription service as a user account for the subscription service.
The Subscription Manager handles both registration and subscriptions for a system. The Subscription Manager is part of the firstboot process for configuring content and updates, but the system can be registered at any time through the Red Hat Subscription Manager UI or CLI. New subscriptions, new products, and updates can be viewed and applied to a system through the Red Hat Subscription Manager tools.
Red Hat Subscription Manager has two tools in its set, a UI-based client to manage the local machine and a CLI client for advanced users (which can be used to work with other applications or in scripting management tasks, like kickstarting machines.
These tools allow administrators to perform three major tasks directly related to managing subscriptions: registering machines, assigning (attaching) subscriptions to systems, and updating the certificates required for authentication. Some minor operations, like updating system facts, are available to help display and track what subscriptions are available.

2.1.1. Launching the Red Hat Subscription Manager UI

Red Hat Subscription Manager is listed as one of the administrative tools in the System > Administration menu in the top management bar.
Red Hat Subscription Manager Menu Option

Figure 2. Red Hat Subscription Manager Menu Option

Alternatively, the Red Hat Subscription Manager UI can be opened from the command line with a single command: 
[root@server1 ~]# subscription-manager-gui
The Red Hat Subscription Manager UI has a single window with tabbed sections that offer quick views into the current state of the system, showing installed products, subscriptions for the system, and available subscriptions the system has access to. These tabs also allow administrators to manage subscriptions by subscribing and unsubscribing the system.
The Red Hat Subscription Manager has three tabs which manage products and subscriptions:
  • The My Subscriptions tab shows all of the current subscriptions that the system is subscribed to.
  • The All Available Subscriptions tab shows all of the subscriptions that are available to the system. The default displays only subscriptions that are compatible with the hardware, but these can be filtered to show any subscriptions which match the hardware, any subscriptions which match installed products, only subscriptions which do not overlap with a currently-attached subscription, or any subscription which matches a given string.
  • The My Installed Products tab shows the currently installed products on the system, along with their subscription status. This does not allow administrators to install software, only to view installed software.
Red Hat Subscription Manager Main Screen

Figure 3. Red Hat Subscription Manager Main Screen

2.1.2. Running the subscription-manager Command-Line Tool

Any of the operations that can be performed through the Red Hat Subscription Manager UI can also be performed by running the subscription-manager tool. This tool has the following format: 
[root@server1 ~]# subscription-manager command [options]
Each command has its own set of options that are used with it. The subscription-manager help and manpage have more information.

Table 1. Frequently-Used subscription-manager Commands

Command Description
Operational Commands
register Registers or identifies a new system to the subscription service.
unregister Unregisters a machine, which strips its subscriptions and removes the machine from the subscription service.
attach Assigns a specific subscription to the machine.
remove Removes a specific subscription or all subscriptions from the machine.
redeem Autosubscribes a machine to a pre-specified subscription that was purchased from a vendor, based on its hardware and BIOS information.
import Manually installs a subscription certificate, rather than contacting the subscription service with a request and then receiving the certificate.
list Lists all of the subscriptions that are compatible with a machine, either subscriptions that are actually consumed by the machine or unused subscriptions that are available to the machine.
Configuration Commands
config Modifies a specified configuration parameter in the Red Hat Subscription Manager configuration file, /etc/rhsm/rhsm.conf. The parameters are passed in the form configuration_area.parameter="value".
service-level Sets the service-level preference for the system to use when selecting subscriptions in autoattach operations.
release Sets the operating system release version preference for the system to use when selecting subscriptions in autoattach operations.
refresh Pulls the latest subscription data from the server. Normally, the system polls the subscription server at a set interval (4 hours by default) to check for any changes in the available subscriptions. The refresh command checks with the subscription server immediately, outside the normal interval.
clean Removes all of the subscription and identity data from the local system, without affecting the consumer information in the subscription service. Any of the subscriptions consumed by the system are still consumed and are not available for other systems to use. The clean command is useful in cases where the local subscription information is corrupted or lost somehow, and the system will be reregistered using the register --consumerid=EXISTING_ID command.
Informative Commands
version Returns the version of the local Red Hat Subscription Manager client, the name of the subscription service the system is registered with, and the version of the subscription service.
identity Handles the identity certificate and registration ID for a system. This command can be used to return the current UUID or generate a new identity certificate.
facts Lists the system information, like the release version, number of CPUs, and other architecture information.
orgs, repos, environments Lists all of the configured organizations, environments, and content repositories that are available to the given user account or system. These commands are used to view information in a multi-org infrastructure. They are not used to configure the local machine or multi-org infrastructure.