Registering Red Hat Enterprise Linux Clients with RHUI

This section contains information about using Red Hat update infrastructure (RHUI) to register traditional and Salt clients running Red Hat Enterprise Linux operating systems.

Traditional clients are available on Red Hat Enterprise Linux 7 only. Red Hat Enterprise Linux 8 and Red Hat Enterprise Linux 9 clients are supported as Salt clients.

If you are running your clients in a public cloud, such as Amazon EC2, use this method.

It is possible to use RHUI in conjunction with the Red Hat content delivery network (CDN) to manage your Red Hat Enterprise Linux subscriptions. For information about using Red Hat CDN, see Registering Red Hat Enterprise Linux Clients with CDN.

You are responsible for connecting Uyuni Server to the Red Hat update infrastructure. All clients that get updates using this RHUI certificate need to be correctly licensed, please check with your cloud provider and the Red Hat terms of service for more information.

When Red Hat Enterprise Linux clients registered with RHUI are switched off, Red Hat might declare the certificate invalid. In this case, you need to turn the client on again, or get a new RHUI certificate.

1. Import Entitlements and Certificates

Red Hat clients require a Red Hat certificate authority (CA) and entitlement certificate, and an entitlement key.

Red Hat clients use a URL to replicate repositories. The URL changes depending on where the Red Hat client is registered.

Red Hat clients can be registered in three different ways:

  • Red Hat content delivery network (CDN) at redhat.com

  • Red Hat Satellite Server

  • Red Hat update infrastructure (RHUI) in the cloud

This guide covers clients registered to Red Hat update infrastructure (RHUI). You must have at least one system registered to RHUI, with an authorized subscription for repository content.

For information about using Red Hat content delivery network (CDN) instead, see Registering Red Hat Enterprise Linux Clients with CDN.

Satellite certificates for client systems require a Satellite server and subscription. Clients using Satellite certificates are not supported with Uyuni Server.

The entitlement certificates and keys need to be copied from the client system to a location that your web browser can access.

The keys and certificates might have slightly different names to those shown here. Your entitlement certificate and the Red Hat CA Certificate file have file extensions of .crt. The key has a file extension of .key.

Procedure: Copying Certificates to the Server

  1. Copy your entitlement certificate and key from the client system, to your workstation:

    Amazon EC2
    cp /etc/pki/rhui/product/content-<version>.crt /<example>/entitlement/
cp /etc/pki/rhui/content-<version>.key /<example>/entitlement/
    Azure

  2. Check the certificate chain using the command:

    openssl s_client -connect rhui-1.microsoft.com:443 -showcerts

    A sample output will look like the following:

    CONNECTED(00000003)
depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Global Root G2
verify return:1
depth=1 C = US, O = Microsoft Corporation, CN = Microsoft Azure TLS Issuing CA 06
verify return:1
depth=0 C = US, ST = WA, L = Redmond, O = Microsoft Corporation, CN = rhui-1.microsoft.com
verify return+

  3. Check the second certificate (CN = Microsoft Azure), if it is the same on your VM, note the certificate name. Refer to the https://docs.microsoft.com/en-us/azure/active-directory/fundamentals/certificate-authorities to download the certificate.

  4. Click the AIA link to download the certificate. The certificate will be downloaded with the .cer suffix.

  5. Convert it to .crt with the command:

    openssl x509 -inform DER -in <example.cer> -out <example.crt>
    Google Cloud Platform
    cp /etc/pki/rhui/product/content.crt /<example>/entitlement/
cp /etc/pki/rhui/key.pem /<example>/entitlement/

  6. Copy the Red Hat CA Certificate file from the client system, to the same location as the entitlement certificate and key:

    Amazon EC2
    cp /etc/pki/rhui/cdn.redhat.com-chain.crt /<example>/entitlement
    Azure

    • Upload the converted certifcate to /<example>/entitlement

    Google Cloud Platform
    cp /etc/pki/rhui/ca.crt /<example>/entitlement

To manage repositories on your Red Hat client, you need to import the CA and entitlement certificates to the Uyuni Server.

This requires that you perform the import procedure three times, to create three entries, one of each for the entitlement certificate, the entitlement key, and the Red Hat certificate.

Procedure: Importing Certificates to the Server

  1. On the Uyuni Server Web UI, navigate to Systems  Autoinstallation  GPG and SSL Keys.

  2. Click Create Stored Key/Cert and set these parameters for the entitlement certificate:

    • In the Description field, type Entitlement-Cert-Date.

    • In the Type field, select SSL.

    • In the Select file to upload field, browse to the location where you saved the entitlement certificate, and select the .crt certificate file.

  3. Click Create Key.

  4. Click Create Stored Key/Cert and set these parameters for the entitlement key:

    • In the Description field, type Entitlement-Key-Date.

    • In the Type field, select SSL.

    • In the Select file to upload field, browse to the location where you saved the entitlement key, and select the .key key file.

  5. Click Create Key.

  6. Click Create Stored Key/Cert and set these parameters for the Red Hat certificate:

    • In the Description field, type redhat-cert.

    • In the Type field, select SSL.

    • In the Select file to upload field, browse to the location where you saved the Red Hat certificate, and select the certificate file.

  7. Click Create Key.

2. Add Software Channels

Before you register Red Hat clients to your Uyuni Server, you need to add the required software channels, and synchronize them.

In the following section, descriptions often default to the x86_64 architecture. Replace it with other architectures if appropriate.

The channels you need for this procedure are:

Table 1. Red Hat Channels - CLI
OS Version Base Channel Client Channel Tools Channel

Red Hat 9

el9-pool-x86_64

-

el9-manager-tools-pool-x86_64, el9-manager-tools-updates-x86_64

Red Hat 8

rhel8-pool-x86_64

-

res8-manager-tools-pool-x86_64

Red Hat 7

rhel-x86_64-server-7

-

res7-suse-manager-tools-x86_64
Procedure: Adding Software Channels at the Command Prompt

  1. At the command prompt on the Uyuni Server, as root, use the spacewalk-common-channels command to add the appropriate channels:

    spacewalk-common-channels \
<base_channel_label> \
<child_channel_label_1> \
<child_channel_label_2> \
... <child_channel_label_n>

  2. If automatic synchronization is turned off, synchronize the channels:

    spacewalk-repo-sync -p <base_channel_label>

  3. Ensure the synchronization is complete before continuing.

The client tools channel provided by spacewalk-common-channels is sourced from Uyuni and not from SUSE.

The AppStream repository provides modular packages. This results in the Uyuni Web UI showing incorrect package information. You cannot perform package operations such as installing or upgrading directly from modular repositories using the Web UI or API.

Alternatively, you can use Salt states to manage modular packages on Salt clients, or use the dnf command on the client. For more information about CLM, see Content Lifecycle Management.

To use RHUI, you need to manually add the required HTTP headers to the configuration file. Without them, you cannot successfully perform a client synchronization.

Procedure: Adding HTTP Headers to the Configuration File

  1. Locate the X-RHUI-ID and X-RHUI-SIGNATURE HTTP headers from your RHUI instance. You can use these commands on the Red Hat client to get the values from the cloud instance metadata API at 169.254.169.254:

    echo "X-RHUI-ID=$(curl -s http://169.254.169.254/latest/dynamic/instance-identity/document|base64|tr -d '\n')"
echo "X-RHUI-SIGNATURE=$(curl -s http://169.254.169.254/latest/dynamic/instance-identity/signature|base64|tr -d '\n')"

  2. Open the /etc/rhn/spacewalk-repo-sync/extra_headers.conf configuration file, and add or edit these lines with the correct information:

    [<channel_label_1>]
X-RHUI-ID=<value>
X-RHUI-SIGNATURE=<value>

[<channel_label_2>]
X-RHUI-ID=<value>
X-RHUI-SIGNATURE=<value>

  3. Replace <channel_label_X> above with the names of the custom channels you are planning to create (see next section):

    [rhel8-baseos-repo]
X-RHUI-ID=...
X-RHUI-SIGNATURE=...

    Red Hat Enterprise Linux may renew these headers at any point in time. In such a case, repeat the procedure to get the new HTTP headers in place.

3. Prepare Custom Repositories and Channels

To mirror the software from RHUI, you need to create custom channels and repositories in Uyuni that are linked to RHUI by a URL. You must have entitlements to these products in your Red Hat Portal for this to work correctly. You can use the yum utility to get the URLs of the repositories you want to mirror:

yum repolist -v | grep baseurl

You can use these repository URLs to create custom repositories. This allows you to mirror only the content you need to manage your clients.

You can only create custom versions of Red Hat repositories if you have the correct entitlements in your Red Hat Portal.

The details you need for this procedure are:

Table 2. Red Hat Custom Repository Settings
Option Setting

Repository URL

The content URL provided by RHUI

Has Signed Metadata?

Uncheck all Red Hat Enterprise repositories

SSL CA Certificate

redhat-cert

SSL Client Certificate

Entitlement-Cert-Date

SSL Client Key

Entitlement-Key-Date
Procedure: Creating Custom Repositories

  1. On the Uyuni Server Web UI, navigate to Software  Manage  Repositories.

  2. Click Create Repository and set the appropriate parameters for the repository.

  3. Click Create Repository.

  4. Repeat for all repositories you need to create.

The channels you need for this procedure are:

Table 3. Red Hat Custom Channels
OS Version Base Product Base Channel

Red Hat 9

RHEL

el9-pool-x86_64

Red Hat 8

RHEL or CentOS 8 Base

rhel8-pool-x86_64

Red Hat 7

RHEL7 Base x86_64

rhel7-pool-x86_64
Procedure: Creating Custom Channels

  1. On the Uyuni Server Web UI, navigate to Software  Manage  Channels.

  2. Click Create Channel and set the appropriate parameters for the channels.

  3. In the Parent Channel field, select the appropriate base channel.

  4. Click Create Channel.

  5. Repeat for all channels you need to create. There should be one custom channel for each custom repository.

You can check that you have created all the appropriate channels and repositories, by navigating to Software  Channel List  All.

For Red Hat 8 clients, add both the Base and AppStream channels. You require packages from both channels. If you do not add both channels, you cannot create the bootstrap repository, due to missing packages.

When you have created all the channels, you can associate them with the repositories you created:

Procedure: Associating Channels with Repositories

  1. On the Uyuni Server Web UI, navigate to Software  Manage  Channels, and click the channel to associate.

  2. Navigate to the Repositories tab, and check the repository to associate with this channel.

  3. Click Update Repositories to associate the channel and the repository.

  4. Repeat for all channels and repositories you need to associate.

  5. OPTIONAL: Navigate to the Sync tab to set a recurring schedule for synchronization of this repository.

  6. Click Sync Now to begin synchronization immediately.

4. Check Synchronization Status

Procedure: Checking Synchronization Progress from the Web UI

  1. In the Uyuni Web UI, navigate to Software  Manage  Channels, then click the channel associated to the repository.

  2. Navigate to the Repositories tab, then click Sync and check Sync Status.

Procedure: Checking Synchronization Progress from the Command Prompt

  1. At the command prompt on the Uyuni Server, as root, use the tail command to check the synchronization log file:

    tail -f /var/log/rhn/reposync/<channel-label>.log

  2. Each child channel generates its own log during the synchronization progress. You need to check all the base and child channel log files to be sure that the synchronization is complete.

Red Hat Enterprise Linux channels can be very large. Synchronization can sometimes take several hours.

5. Manage GPG Keys

Clients use GPG keys to check the authenticity of software packages before they are installed. Only trusted software can be installed on clients.

Trusting a GPG key is important for security on clients. It is the task of the administrator to decide which keys are needed and can be trusted. Because a software channel cannot be used when the GPG key is not trusted, the decision of assigning a channel to a client depends on the decision of trusting the key.

For more information about GPG keys, see GPG Keys.

6. Register Clients

To register your Red Hat clients, you need a bootstrap repository. By default, bootstrap repositories are automatically created, and regenerated daily for all synchronized products. You can manually create the bootstrap repository from the command prompt, using this command:

mgr-create-bootstrap-repo

For more information on registering your clients, see Client Registration.