Understanding Software Sources

Guidelines for Adding Vendor Software Sources

When you add vendor sources to OS Management Hub, follow these guidelines:

• Add vendor software source to OS Management Hub before registering Oracle Linux instances with the service.

  Note
  
  

  Autonomous Linux instances require a minimum set of vendor software sources which are automatically added to OS Management Hub when you register an Autonomous Linux instance. For more information, see Mandatory Software Sources.

• Add at least the minimum software sources to support the OS version of an instance.

  • Oracle Linux 8 and Oracle Linux 9 require the BaseOS and AppStream software sources.
  • If using Oracle Linux Unbreakable Enterprise Kernel (UEK), add the UEK software source to ensure that instances get kernel updates and patches.
  • See Managing Software in Oracle Linux for more information on Oracle Linux repositories.

• Only add the content that's relevant to your environment to follow security best practices. This is the first level of control you have over the content available to instances in OS Management Hub. See Security: Selecting Software Sources.

  • For example, if you aren't using the Gluster AppStream repository in Oracle Linux 8, don't add that software sources to the service.

Creating a Snapshot of a Vendor Software Source

A common use of custom software sources is to create a snapshot of a vendor software source. To do this, create a custom software source with auto-update disabled, auto-resolve disabled, and no filters or package list specified. This creates a copy of the vendor software source but with packages that remain at the versions available when the source was created. This can be useful if you want instances to have access to a vendor software source, but want to limit access to future package updates.

Automatically Resolving Dependencies

When creating a custom software source, you can choose to have the service automatically resolve package and module dependencies by enabling the Automatically resolve packages and module dependencies option. Dependency resolution can only include packages within vendor software sources that are part of the custom source. If a dependent package resides in an vendor source not included in the custom source, the dependent package will not be included and the custom software source creation will fail.

When using the auto-resolve option, the custom software source also includes the package dependencies of your filters or package list. Therefore, when viewing available packages, you might see packages in the custom software source not explicitly specified by your filters or package list.

If you don't provide filters or a packages list, the auto-resolve option is ignored and a snapshot of the vendor software sources is created. See Creating a Snapshot of a Vendor Software Source.

Automatically Updating Content

When creating a custom software source, you can choose to have the service automatically update the content of the custom software source to include the latest available packages by enabling the Automatically update content option. OS Management Hub checks for updates once every 24 hours.

If using filters and the auto-update option, the service only updates content when the filter doesn't specify a version (such as Include | Package | zsh). When the filter specifies a version (such as Include | Package | zsh | 5.5.1-6.el8), the service ignores the auto-update option and the package remains at the specified version.

If using a package list and the auto-update option, the service ignores the auto-update option for packages specified in the list. Package lists require the full version of the package to be specified and these packages remain at the version specified.

If also using the auto-resolve option, dependent packages that aren't specified in the package list or by a filter could be updated.

You can't use the auto-update option with versioned custom software sources.

Using Filters and Package Lists

You can use either filters or a package list to identify specific content that the custom software source contains. You define filters or a package list when creating a custom software source or when editing filters or the package list for a custom software source.

Filters

Use filters to either include or exclude content to build custom software sources. The types of filters include:

• Group to specify a package group. The package groups available depend on the software sources included in the custom source.
• Module to specify a module stream and module stream profile.
• Package to specify a package name and version. The acceptable package version format is 'epoch:version-release' or 'version-release'. For example, package name: edk2-ovmf and package version: 1:20210616-3.el8.

If using the auto-resolve dependencies option, the custom software source also includes the package dependencies of your filters. Therefore, when viewing available packages, you might see additional packages in the custom software source not explicitly specified by your filters.

If using the auto-update option, when your filter specifies a version of a package, the option is ignored for that package and it remains at the specified version. However, when your filter specifies a package without a version, the service will update the package to the latest available version.

Additionally, you can use the latest-only option to limit packages and modules to the latest versions. This option adds only the latest version of the package or module stream within the constraints of your filters or package list.

Package List

Use a package list to specify which packages to include in the custom software source. You can run rpm -qa on a reference instance to create a list of packages.

For example, the format of the packages would be:

pam-1.3.1-27.el8.x86_64
openssl-libs-1.1.1k-12.el8_9.x86_64
libreport-filesystem-2.9.5-15.0.4.el8.x86_64

The auto-update and latest-only options are ignored when using a package list. The package versions remain at the levels specified in the list.

Limiting Packages and Modules to the Latest Version

When creating a custom software source, you can choose to limit the packages and modules included in the source to only the latest available versions. Enabling the Only include the latest version option adds only the latest version of the package or module stream within the constraints of your filters or package list. This gives you more control over the content of the custom software source and prevents instances from installing older versions of packages.

When using the latest-only with a package list, the service includes only the specified version of the package.

When the latest-only option is enabled, 'Include' filters behave as follows:

• For a package filter that doesn't specify a version, includes only the latest available version of the package.
• For a package filter that specifies a version, includes only the specified version of the package.
• For a module filter that doesn't specify a stream, includes all available streams. Within each stream, includes only the latest version of packages.
• For a module filter that specifies a stream, includes only the latest version of packages for the specified stream.
• For a group filter, includes only the latest version of packages for the group.

If also using the auto-resolve option, dependent packages that aren't constrained by the package list or by a filter are limited to the latest version available.

As an example, consider the following filters for an Oracle Linux 8 custom software source: