Registering CentOS Clients

This section contains information about registering traditional and Salt clients running CentOS operating systems.

  • CentOS repository URLs are available from SUSE Customer Center.

  • Packages and metadata are provided by CentOS, not by SUSE.

  • For supported products, see the release notes and the support table at Supported CentOS Features.

CentOS clients are based on CentOS and are unrelated to SUSE Linux Enterprise Server with Expanded Support, RES, Red Hat, or Expanded Support. You are responsible for arranging access to CentOS base media repositories and CentOS installation media, as well as connecting SUSE Manager Server to the CentOS content delivery network.

1. Add Software Channels

Before you can register CentOS clients to your SUSE Manager Server, you need to add the required software channels, and synchronize them.

The architectures currently supported are: x86_64 and aarch64. For full list of supported products and architectures, see Supported Clients and Features.

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

For example, when working with x86_64 architecture, you need this products:

Table 1. CentOS Products - WebUI
OS Version Product Name

CentOS 7

CentOS 7 x86_64
Procedure: Adding Software Channels

  1. In the SUSE Manager Web UI, navigate to Admin  Setup Wizard  Products.

  2. Locate the appropriate products for your client operating system and architecture using the search bar, and check the appropriate product. This will automatically check all mandatory channels. Also all recommended channels are checked as long as the include recommended toggle is turned on. Click the arrow to see the complete list of related products, and ensure that any extra products you require are checked.

  3. Click Add Products and wait until the products have finished synchronizing.

Alternatively, you can add channels at the command prompt. The channels you need for this procedure are:

Table 2. CentOS Channels - CLI
OS Version Base Channel

CentOS 7

centos7-x86_64
Procedure: Adding Software Channels at the Command Prompt

  1. At the command prompt on the SUSE Manager Server, as root, use the mgr-sync command to add the appropriate channels:

    mgr-sync add channel <channel_label_1>
mgr-sync add channel <channel_label_2>
mgr-sync add channel <channel_label_n>

  2. Synchronization starts automatically. If you want to synchronize the channels manually, use:

    mgr-sync sync --with-children <channel_name>

  3. Ensure the synchronization is complete before continuing.

If you are using modular channels, you must enable the Python 3.6 module stream on the client. If you do not provide Python 3.6, the installation of the spacecmd package will fail.

You might notice some disparity in the number of packages available in the AppStream channel between upstream and the SUSE Manager channel. You might also see different numbers if you compare the same channel added at a different point in time. This is due to the way that CentOS manages their repositories. CentOS removes older version of packages when a new version is released, while SUSE Manager keeps all of them, regardless of age.

The AppStream repository provides modular packages. This results in the SUSE Manager 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.

2. Check Synchronization Status

Procedure: Checking Synchronization Progress from the Web UI

  1. In the SUSE Manager Web UI, navigate to Admin  Setup Wizard and select the Products tab. This dialog displays a completion bar for each product when they are being synchronized.

  2. Alternatively, you can navigate to Software  Manage  Channels, then click the channel associated to the repository. 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 SUSE Manager 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.

3. Create an Activation Key

You need to create an activation key that is associated with your CentOS channels.

For more information on activation keys, see Activation Keys.

4. Trust GPG Keys on Clients

Operating systems either trust their own GPG keys directly or at least ship them installed with the minimal system. But third party packages signed by a different GPG key need manual handling. The clients can be successfully bootstrapped without the GPG key being trusted. However, you cannot install new client tool packages or update them until the keys are trusted.

Salt clients now use GPG key information entered for a software channel to manage the trusted keys. When a software channel with GPG key information is assigned to a client, the key is trusted as soon as the channel is refreshed or the first package gets installed from this channel.

The GPG key URL parameter in the software channel page can contain multiple key URLs separated by "whitespace". In case it is a file URL, the GPG key file must be deployed on the client before the software channel is used.

The GPG keys for the Client Tools Channels of Red Hat based clients are deployed on the client into /etc/pki/rpm-gpg/ and can be referenced with file URLs. Same is the case with the GPG keys of Expanded Support clients. Only in case a software channel is assigned to the client they will be imported and trusted by the system.

Because Debian based systems sign only metadata, there is no need to specify extra keys for single channels. If a user configures an own GPG key to sign the metadata as described in "Use Your Own GPG Key" in Signing Repository Metadata the deployment and trust of that key is executed automatically.

4.1. User defined GPG keys

Users can define their own GPG keys to be deployed to the client.

By providing some pillar data and providing the GPG key files in the Salt filesystem, they are automatically deployed to the client.

These keys are deployed into /etc/pki/rpm-gpg/ on RPM based operating systems and to /usr/share/keyrings/ on Debian systems:

Define the pillar key [literalcustom_gpgkeys for the client you want to deploy the key to and list the names of the key file.

cat /srv/pillar/mypillar.sls
custom_gpgkeys:
  - my_first_gpg.key
  - my_second_gpgkey.gpg

Additionally in the Salt filesystem create a directory named gpg and store there the GPG key files with the name specified in the custom_gpgkeys pillar data.

ls -la /srv/salt/gpg/
/srv/salt/gpg/my_first_gpg.key
/srv/salt/gpg/my_second_gpgkey.gpg

The keys are now deployed to the client at /etc/pki/rpm-gpg/my_first_gpg.key and /etc/pki/rpm-gpg/my_second_gpgkey.gpg.

The last step is to add the URL to the GPG key URL field of the software channel. Navigate to Software  Manage  Channels and select the channel you want to modify. Add to GPG key URL the value file:///etc/pki/rpm-gpg/my_first_gpg.key.

4.2. GPG Keys in Bootstrap Scripts

Procedure: Trusting GPG Keys on Clients Using a Bootstrap Script

  1. On the SUSE Manager Server, at the command prompt, check the contents of the /srv/www/htdocs/pub/ directory. This directory contains all available public keys. Take a note of the key that applies to the channel assigned to the client you are registering.

  2. Open the relevant bootstrap script, locate the ORG_GPG_KEY= parameter and add the required key. For example:

    uyuni-gpg-pubkey-0d20833e.key

    You do not need to delete any previously stored keys.

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. A software channel cannot be assigned to a client when the GPG key is not trusted.

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. A software channel cannot be assigned to a client when the GPG key is not trusted.

For more information about GPG keys, see GPG Keys.

6. Register Clients

To register your 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.

7. Manage Errata

When you update CentOS clients, the packages do not include metadata about the updates. You can use a third-party errata service to obtain this information.

The third-party errata service described here, CEFS, is provided and maintained by the community. It is not supported by SUSE.

The authors of CEFS provide patches or errata on a best-effort basis, in the hope they are useful but with no guarantees of correctness or currency. This could mean that the patch dates could be incorrect, and in at least one case, the published data was shown to be more than a month old. For more information on these cases, see https://github.com/stevemeier/cefs/issues/28#issuecomment-656579382 and https://github.com/stevemeier/cefs/issues/28#issuecomment-656573607.

Any problems or delays with the patch data might result in unreliable patch information being imported to your SUSE Manager Server. This would cause reports, audits, CVE updates, or other patch-related information to also be incorrect. Please consider alternatives to using this service, such as independently verifying patch data, or choosing a different operating system, depending on your security-related requirements and certifications criteria.
Procedure: Installing an Errata Service

  1. On the SUSE Manager Server, from the command prompt, as root, add the sle-module-development-tools module:

    SUSEConnect --product sle-module-development-tools/15.2/x86_64

  2. Install errata service dependencies:

    zypper in  perl-Text-Unidecode

  3. Add or edit this line in /etc/rhn/rhn.conf:

    java.allow_adding_patches_via_api = centos7-x86_64-updates,centos7-x86_64,centos7-x86_64-extras

  4. Restart Tomcat:

    systemctl restart tomcat

  5. Create a file for your errata script:

    touch /usr/local/bin/cent-errata.sh

  6. Edit the new file to include this script, editing the repository details as required. This script fetches the errata details from an external errata service, unpacks it, and publishes the details:

    #!/bin/bash
mkdir -p /usr/local/centos
cd /usr/local/centos
rm *.xml
wget -c http://cefs.steve-meier.de/errata.latest.xml
wget -c https://www.redhat.com/security/data/oval/v2/RHEL7/rhel-7.oval.xml.bz2
bzip2 -d rhel-7.oval.xml.bz2
wget -c http://cefs.steve-meier.de/errata-import.tar
tar xvf errata-import.tar
chmod +x /usr/local/centos/errata-import.pl
export SPACEWALK_USER='<adminname>';export SPACEWALK_PASS='<password>'
/usr/local/centos/errata-import.pl --server '<servername>' \
--errata /usr/local/centos/errata.latest.xml  \
--include-channels=centos7-x86_64-updates,centos7-x86_64,centos7-x86_64-extras \
--publish --rhsa-oval /usr/local/centos/rhel-7.oval.xml

  7. Set up a cron job to run the script daily:

    ln -s /usr/local/bin/cent-errata.sh /etc/cron.daily

For more information on this tool, see https://cefs.steve-meier.de/.