Chapter 2. Setting up image builder

Use image builder to create your customized RHEL for Edge images. After you install image builder on a RHEL system, image builder is available as an application in RHEL web console. You can also access image builder through a command line interface in the composer-cli tool.


It is recommended to install image builder on a virtual machine.

In the environment where you want to install image builder, ensure that you first meet the system requirements and then install it.

2.1. Image builder system requirements

The environment where RHEL image builder runs, for example a virtual machine, must meet the requirements that are listed in the following table.


Running RHEL image builder inside a container is not supported.

Table 2.1. Image builder system requirements


Minimal Required Value

System type

A dedicated virtual machine


2 cores


4 GiB

Disk space

20 GiB

Access privileges

Administrator level (root)


Connectivity to Internet


The 20 GiB disk space requirement is enough to install and run image builder in the host. To build and deploy image builds, you must allocate additional dedicated disk space.

2.2. Installing image builder

To install image builder on a dedicated virtual machine, follow these steps:


  • The virtual machine is created and is powered on.
  • You have installed RHEL and you have subscribed to RHSM or Red Hat Satellite.
  • You have enabled the BaseOS and AppStream repositories to be able to install the RHEL image builder packages.


  1. Install the following packages on the virtual machine.

    • osbuild-composer
    • composer-cli
    • cockpit-composer
    • bash-completion
    • firewalld
    # dnf install osbuild-composer composer-cli cockpit-composer bash-completion firewalld

    Image builder is installed as an application in RHEL web console.

  2. Reboot the virtual machine
  3. Configure the system firewall to allow access to the web console:

    # firewall-cmd --add-service=cockpit && firewall-cmd --add-service=cockpit --permanent
  4. Enable image builder.

    # systemctl enable osbuild-composer.socket cockpit.socket --now

    The osbuild-composer and cockpit services start automatically on first access.

  5. Load the shell configuration script so that the autocomplete feature for the composer-cli command starts working immediately without reboot:

    $ source /etc/bash_completion.d/composer-cli

Additional resources