Chapter 3. Composing a RHEL for Edge image using Image Builder in RHEL web console

Use Image Builder to create a custom RHEL for Edge image (OSTree commit).

To access Image Builder and to create your custom RHEL for Edge image, you can either use the RHEL web console interface or the command-line interface.

This section provides information about accessing Image Builder and creating RHEL for Edge images using the RHEL web console. To access Image Builder and to create RHEL for Edge images using CLI, see, Chapter 4, Composing a RHEL for Edge image using Image Builder command-line.

You can compose RHEL for Edge images using Image Builder in RHEL web console by performing the following high-level steps:

  1. Access Image Builder in RHEL web console
  2. Create a blueprint for RHEL for Edge image
  3. Create a RHEL for Edge image
  4. Download the RHEL for Edge image
  5. Create a user account for the RHEL for Edge image blueprint

3.1. Accessing Image Builder in the RHEL web console

To access Image Builder in RHEL web console, ensure that you have met the following prerequisites and then follow the procedure.

Prerequisites

  • You have installed a RHEL system.
  • You have administrative rights on the system.
  • You have subscribed the RHEL system to Redhat Subscription Manager (RHSM) or to Redhat Satellite server.
  • The system is powered on and accessible over network.
  • You have installed Image Builder on the system.

Procedure

  1. On the RHEL system, access https://localhost:9090/ in a web browser.
  2. For more information about how to remotely access Image Builder, see Managing systems using the RHEL 8 web console document.
  3. Log in to the web console using an administrative user account.
  4. On the web console, in the left hand menu, click Apps.
  5. Click Image Builder.
  6. The Image Builder dashboard appears in the right pane.
  7. You can now proceed to create a blueprint for the RHEL for Edge images.

3.2. Creating a RHEL for Edge image blueprint using Image Builder in RHEL web console

To create a RHEL for Edge image blueprint using Image Builder in RHEL web console, ensure that you have met the following prerequisites and then follow the procedure.

Prerequisites

  • On a RHEL system, you have opened the Image Builder dashboard.

Procedure

  1. On the Image Builder dashboard, click Create Blueprint.

    A Create Blueprint dialogue box appears.

  2. Specify a name and description for the blueprint that you want to create.
  3. Click Create.

    The dashboard displays a list of available components.

  4. From the Available Components, click + for the component that you want to include in the blueprint.

    To search for a specific component, enter the component name in the Filter By Name text box, and then press Enter. The Component Details pane displays the component details and its dependent components. You can select the required version. The web console selects the latest version by default.

    NOTE: To remove a component from the blueprint, in the Available Components pane, click - against the component name.

  5. In the Components Details pane, click Add.
  6. Click Commit to save the blueprint.

    A dialog box with the blueprint summary appears.

  7. Click Commit.
  8. From the breadcrumbs, click Back to Blueprints.

    The Image Builder dashboard lists the blueprints that you created.

3.3. Creating a RHEL for Edge image using Image Builder in RHEL web console

To create a RHEL for Edge image using Image Builder in RHEL web console, ensure that you have met the following prerequisites and then follow the procedure.

Prerequisites

  • On a RHEL system, you have accessed the Image Builder dashboard.
  • You have created a blueprint for RHEL for Edge image.

Procedure

  1. On the Image Builder dashboard, for the blueprint that you have created for RHEL for Edge image, click Create Image. To search for a specific blueprint, enter the blueprint name in the Filter By Name text box, and then press Enter.
  2. On the Create Image window, perform the following steps:

    1. From the Type dropdown list, select “RHEL for Edge Commit (.tar)”.
    2. In the Parent commit textbox, specify a previous commit, or leave it empty; if you do not have a commit at this time.
    3. In the Ref textbox, specify a name for your commit. By default, the web console specifies rhel/8/arch_name/edge.
    4. Click Create.

      Note

      If you have made any earlier edits to the blueprint, but have not committed them, then click Commit and create.

      Image Builder creates a RHEL for Edge image for the blueprint that you created.

      To view the RHEL for Edge image creation progress, click the blueprint name from the breadcrumbs, and then click the Images tab.

      Note

      The image creation process takes a few minutes to complete. To abort the image creation process, click Stop from the More Options menu.

3.4. Downloading a RHEL for Edge image

After the Image Builder successfully creates the RHEL for Edge image, download the image on the local host.

Procedure

To download an image:

  1. Click Download from the More Options menu.

    The Image Builder downloads the file at your default download location.

The downloaded file consists of a .tar file with an OSTree repository. This repository contains the commit and a json file which contains information metadata about the repository content.

3.5. Adding a source to RHEL for Edge image blueprint

The sources defined in Image Builder provide the contents that you can add to blueprints. These sources are global and therefore available to all blueprints. The System sources are repositories that are set up locally on your computer and cannot be removed from Image Builder. You can add additional custom sources and thus be able to access other contents than the System sources available on your system. The following steps describe how to add a Source to your local system.

Prerequisites

  • You have opened the Image Builder interface of the RHEL 8 web console in a browser.

Procedure

  1. Click the ⫶ Manage Sources button in the upper right corner.

    A pop-up window appears with the available sources, their names and descriptions.

  2. On the right side of the pop-up window, click the Add Source button.
  3. Add the desired Source name, the Source path, and the Source Type.

    The Security field is optional.

  4. Click Add Source button. The screen shows the available sources window and lists the source you have added.

As a result, the new System source is available and ready to be used or edited.

3.6. Creating an administrative user account for a RHEL for Edge image blueprint

To build and deploy the RHEL for Edge image that you have created, you must have administrative user privileges on the image blueprint. Use Image Builder to create an administrative user account for the image blueprint. You can then use this user account to deploy the image that you have created. For the administrative user account you can either have a password-based access or an SSH-key based access.

Prerequisites

  • You have created an SSH key that you can use for the user account to be created.
  • You have accessed the Image Builder dashboard in the RHEL web console.
  • You have created a blueprint for RHEL for Edge image.

Procedure

  1. On the Image Builder dashboard, find the blueprint for RHEL for Edge image.

    To search a required blueprint, specify the blueprint name in the Filter by Name text box and then press Enter.

  2. Click the blueprint name.

    Image Builder displays the blueprint details.

  3. On the Customizations tab, click Create User Account.
  4. On the Create User Account dialogue box, specify the required details and a password for the user account.

    For password-based access, specify a password for the user account.

    For SSH-based access, specify an SSH key for the user account.

Note

Ensure that you select the Server administrator check box, if you want to provide administrators rights to the user account you are creating.

Image Builder creates a specified user account and displays the details.

You can create additional user accounts, if required.