Red Hat Enterprise Linux hosts can run in two deployment models, and each model determines how you install the flightctl-agent and which Red Hat Edge Manager capabilities are available on the device. Understanding the distinction helps you choose the correct installation path for your environment.

Note

For a side-by-side comparison of Red Hat Edge Manager capabilities by OS mode (application workloads, configuration overlays, Software Catalog access, and OS update support), see Package-mode management capabilities and limitations in the Additional resources section.

Image mode uses bootable container (bootc) images as the operating system (OS) delivery mechanism. Image-mode hosts receive transactional OS updates through Red Hat Edge Manager, and the greenboot health check framework provides automatic rollback if an update fails. When you install the agent on an image-mode host with dnf install flightctl-agent, the installer automatically pulls the flightctl-greenboot subpackage through a Recommends: (weak) dependency.

Package mode is the traditional Red Hat Enterprise Linux deployment model managed through dnf or yum. Package-mode hosts do not use bootc or rpm-ostree for OS delivery, so they do not support transactional OS image updates or greenboot-based rollback through Red Hat Edge Manager. When you install the agent on a package-mode host, you exclude the flightctl-greenboot subpackage by disabling weak dependencies during installation.

The flightctl-greenboot subpackage

The flightctl-agent RPM Package Manager (RPM) package does not bundle greenboot integration directly. Greenboot-related components are packaged separately in the flightctl-greenboot subpackage, which contains the following:

• Greenboot health check scripts that monitor agent stability after OS updates
• A bootc timer masking configuration
• The flightctl-configure-greenboot service that manages greenboot settings on each boot

The flightctl-greenboot subpackage is declared as a Recommends: (weak) dependency of flightctl-agent. This dependency model controls which components are installed on each host type:

• Image-mode hosts: Run sudo dnf install flightctl-agent. The installer pulls flightctl-greenboot automatically because weak dependencies are enabled by default. This behavior is unchanged from previous releases.
• Package-mode hosts: Run sudo dnf install --setopt=install_weak_deps=False flightctl-agent. Disabling weak dependencies excludes flightctl-greenboot, keeping greenboot and bootc dependencies off the host.

Upgrading from a monolithic agent package

If you upgrade from a monolithic flightctl-agent package that bundled greenboot integration directly, dnf installs the flightctl-greenboot subpackage automatically when greenboot is already present on the system. On systems where greenboot is not installed, the subpackage is added as a weak dependency and follows the same install_weak_deps behavior described above.

Image-mode installation workflows are unchanged. No additional steps are required when upgrading image-mode devices.