Chapter 5. Creating system images with Image Builder web console interface

Procedure

1. Open https://localhost:9090/ in a web browser on the system where Image Builder is installed.

   For more information on how to remotely access Image Builder, see Managing systems using the RHEL web console document.

2. Log into the web console with credentials for a user account with sufficient privileges on the system.

3. To display the Image Builder controls, click the Image Builder icon, which is in the upper-left corner of the window.

   The Image Builder view opens, listing existing blueprints.

Procedure

1. Click Create Blueprint in the top right corner.

   A pop-up appears with fields for the blueprint name and description.

2. Fill in the name of the blueprint, its description, then click Create.

   The screen changes to blueprint editing mode.

3. Add components that you want to include in the system image:

   1. On the left, enter all or part of the component name in the Available Components field and press Enter.

      The search is added to the list of filters under the text entry field, and the list of components below is reduced to those that match the search.

      If the list of components is too long, add further search terms in the same way.

   2. The list of components is paged. To move to other result pages, use the arrows and entry field above the component list.
   3. Click the name of the component you intend to use to display its details. The right pane fills with details of the components, such as its version and dependencies.
   4. Select the version you want to use in the Component Options box, with the Version Release dropdown.
   5. Click Add in the top left.
   6. If you added a component by mistake, remove it by clicking the …​ button at the far right of its entry in the right pane, and select Remove in the menu.

   Note

   If you do not intend to select a version for some components, you can skip the component details screen and version selection by clicking the + buttons on the right side of the component list.

4. To save the blueprint, click Commit in the top right. A dialog with a summary of the changes pops up. Click Commit.

   A small pop-up on the right informs you of the saving progress and then the result.

5. To exit the editing screen, click Back to Blueprints in the top left.

   The Image Builder view opens, listing existing blueprints.

Procedure

1. Locate the blueprint that you want to edit by entering its name or a part of it into the search box at top left, and press Enter.

   The search is added to the list of filters under the text entry field, and the list of blueprints below is reduced to those that match the search.

   If the list of blueprints is too long, add further search terms in the same way.

2. On the right side of the blueprint, press the Edit Blueprint button that belongs to the blueprint.

   The view changes to the blueprint editing screen.

3. Remove unwanted components by clicking their ⫶ button at the far right of its entry in the right pane, and select Remove in the menu.

4. Change version of existing components:

   1. On the Blueprint Components search field, enter component name or a part of it into the field under the heading Blueprint Components and press Enter.

      The search is added to the list of filters under the text entry field, and the list of components below is reduced to those that match the search.

      If the list of components is too long, add further search terms in the same way.

   2. Click the ⫶ button at the far right of the component entry, and select View in the menu.

      A component details screen opens in the right pane.

   3. Select the desired version in the Version Release drop-down menu and click Apply Change in top right.

      The change is saved and the right pane returns to listing the blueprint components.

5. Add new components:

   1. On the left, enter component name or a part of it into the field under the heading Available Components and press Enter.

      The search is added to the list of filters under the text entry field, and the list of components below is reduced to those that match the search.

      If the list of components is too long, add further search terms in the same way.

   2. The list of components is paged. To move to other result pages, use the arrows and entry field above the component list.
   3. Click the name of the component you intend to use to display its details. The right pane fills with details of the components, such as its version and dependencies.
   4. Select the version you want to use in the Component Options box, with the Version Release drop-down menu.
   5. Click Add in the top right.

   6. If you added a component by mistake, remove it by clicking the ⫶ button at the far right of its entry in the right pane, and select Remove in the menu.

      Note

      If you do not intend to select a version for some components, you can skip the component details screen and version selection by clicking the + buttons on the right side of the component list.

6. Commit a new version of the blueprint with your changes:

   1. Click the Commit button in top right.

      A pop-up window with a summary of your changes appears.

   2. Review your changes and confirm them by clicking Commit.

      A small pop-up on the right informs you of the saving progress and the results. A new version of the blueprint is created.

   3. In the top left, click Back to Blueprints to exit the editing screen.

      The Image Builder view opens, listing existing blueprints.

Procedure

1. Find out the name of the blueprint: Open the Image Builder (Image builder) tab on the left in the RHEL web console to see the name of the blueprint.
2. Navigate to the CLI in web console: Open the system administration tab on the left, then select the last item Terminal from the list on the left.

3. Enter the super-user (root) mode:

   $ sudo bash

   Provide your credentials when asked. Note that the terminal does not reuse your credentials you entered when logging into the web console.

   A new shell with root privileges starts in your home directory.

4. Export the blueprint to a file:

   # composer-cli blueprints save BLUEPRINT-NAME

5. Edit the file BLUEPRINT-NAME.toml with a text editor and add the users and groups.

   Important

   RHEL web console does not have any built-in feature to edit text files on the system, so the use of a CLI text editor is required for this step.

   1. For every user to be added, add this block to the file:

      [[customizations.user]]
      name = "USER-NAME"
      description = "USER-DESCRIPTION"
      password = "PASSWORD-HASH"
      key = "ssh-rsa (...) key-name"
      home = "/home/USER-NAME/"
      shell = "/usr/bin/bash"
      groups = ["users", "wheel"]
      uid = NUMBER
      gid = NUMBER

      Replace PASSWORD-HASH with the actual password hash. To generate the hash, use a command such as this:

      $ python3 -c 'import crypt,getpass;pw=getpass.getpass();print(crypt.crypt(pw) if (pw==getpass.getpass("Confirm: ")) else exit())'

      Replace ssh-rsa (…​) key-name with the actual public key.

      Replace the other placeholders with suitable values.

      Leave out any of the lines as needed, only the user name is required.

   2. For every user group to be added, add this block to the file:

      [[customizations.group]]
      name = "GROUP-NAME"
      gid = NUMBER

   3. Increase the version number.
   4. Save the file and close the text editor.

6. Import the blueprint back into Image Builder:

   # composer-cli blueprints push BLUEPRINT-NAME.toml

   Note that you must supply the file name including the .toml extension, while in other commands you use only the name of the blueprint.

7. To verify that the contents uploaded to Image Builder match your edits, list the contents of blueprint:

   # composer-cli blueprints show BLUEPRINT-NAME

   Check if the version matches what you put in the file and if your customizations are present.

   Important

   The Image Builder plugin for RHEL web console does not show any information that could be used to verify that the changes have been applied, unless you also edited the packages included in the blueprint.

8. Exit the privileged shell:

   # exit

9. Open the Image Builder (Image builder) tab on the left and refresh the page, in all browsers and all tabs where it was opened.

   This prevents state cached in the loaded page from accidentally reverting your changes.

Procedure

1. Locate the blueprint that you want to build an image by entering its name or a part of it into the search box at top left, and press Enter.

   The search is added to the list of filters under the text entry field, and the list of blueprints below is reduced to those that match the search.

   If the list of blueprints is too long, add further search terms in the same way.

2. On the right side of the blueprint, press the Create Image button that belongs to the blueprint.

   A pop-up window appears.

3. Select the image type and press Create.

   A small pop-up in the top right informs you that the image creation has been added to the queue.

4. Click the name of the blueprint.

   A screen with details of the blueprint opens.

5. Click the Images tab to switch to it. The image that is being created is listed with the status In Progress.

   Note

   Image creation takes a longer time, measured in minutes. There is no indication of progress while the image is created.

   To abort image creation, press its Stop button on the right.

6. After the image is successfully created, the Stop button is replaced by a Download button. Click this button to download the image to your system.

Procedure

1. Click the ⫶ Manage Sources button in the top 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.

Procedure

1. Locate the blueprint that you want to create a user account for by entering its name or a part of it into the search box at the top left, and press Enter.

   The search is added to the list of filters under the text entry field, and the list of blueprints below is reduced to those that match the search.

2. Click on the blueprint name to display the blueprint details.

   

3. Click Create User Account.

   This will open a window with fields for user account creation.

   
4. Fill in the details. Notice that when you insert the name, the User name field autocompletes, suggesting a username.
5. After you have inserted all the desired details, click Create.

6. The created user account appears showing all the information you have inserted.

   
7. To create further user accounts for the blueprint, repeat the process.

Procedure

1. Locate the blueprint that you want to create a user account for by entering its name or a part of it into the search box at the top left, and press Enter.

   The search is added to the list of filters under the text entry field, and the list of blueprints below is reduced to those that match the search.

2. Click on the blueprint name to display the blueprint details.

   

3. Click Create User Account.

   This will open a window with fields for user account creation

   

4. Fill in the details. Notice that when you insert the name, the User name field autocompletes, suggesting a username.

   If you want to provide administrators rights to the user account you are creating, check the Role field.

   Paste the content of your public SSH key file.

5. After you have inserted all the desired details, click Create.

6. The new user account will appear in the user list, showing all the information you have inserted.

   
7. If you want to create more user accounts for the blueprint, repeat the process.