Chapter 8. Using the Ignition tool for the RHEL for Edge Simplified Installer images

Procedure

1. Create a Butane Config file and save it in the .bu format. You must specify the variant entry as r4e, and the version entry as 1.0.0, for RHEL for Edge images. The butane r4e variant on version 1.0.0 targets Ignition spec version 3.3.0. The following is a Butane Config YAML file example:

   variant: r4e
   version: 1.0.0
   ignition:
     config:
       merge:
         - source: http://192.168.122.1:8000/sample.ign
   passwd:
     users:
       - name: core
         groups:
           - wheel
         password_hash: password_hash_here
         ssh_authorized_keys:
           - ssh-ed25519 some-ssh-key-here
   storage:
     files:
       - path: /etc/NetworkManager/system-connections/enp1s0.nmconnection
         contents:
           inline: |
             [connection]
             id=enp1s0
             type=ethernet
             interface-name=enp1s0
             [ipv4]
             address1=192.168.122.42/24,192.168.122.1
             dns=8.8.8.8;
             dns-search=
             may-fail=false
             method=manual
         mode: 0600
       - path: /usr/local/bin/startup.sh
         contents:
           inline: |
             #!/bin/bash
             echo "Hello, World!"
         mode: 0755
   systemd:
     units:
       - name: hello.service
         contents: |
           [Unit]
           Description=A hello world
           [Install]
           WantedBy=multi-user.target
         enabled: true
       - name: fdo-client-linuxapp.service
         dropins:
           - name: log_trace.conf
             contents: |
               [Service]
               Environment=LOG_LEVEL=trace

2. Run the following command to consume the Butane Config YAML file and generate an Ignition Config in the JSON format:

   $ ./path/butane example.bu
   {"ignition":{"config":{"merge":[{"source":"http://192.168.122.1:8000/sample.ign"}]},"timeouts":{"httpTotal":30},"version":"3.3.0"},"passwd":{"users":[{"groups":["wheel"],"name":"core","passwordHash":"password_hash_here","sshAuthorizedKeys":["ssh-ed25519 some-ssh-key-here"]}]},"storage":{"files":[{"path":"/etc/NetworkManager/system-connections/enp1s0.nmconnection","contents":{"compression":"gzip","source":"data:;base64,H4sIAAAAAAAC/0yKUcrCMBAG3/csf/ObUKQie5LShyX5SgPNNiSr0NuLgiDzNMPM8VBFtHzoQjkxtPp+ITsrGLahKYyyGtoqEYNKwfeZc32OC0lKDb179rfg/HVyPgQ3hv8w/v0WT0k7T+7D/S1Dh7S4MRU5h1XyzqvsHVRg25G4iD5kp1cAAAD//6Cvq2ihAAAA"},"mode":384},{"path":"/usr/local/bin/startup.sh","contents":{"source":"data:;base64,IyEvYmluL2Jhc2gKZWNobyAiSGVsbG8sIFdvcmxkISIK"},"mode":493}]},"systemd":{"units":[{"contents":"[Unit]\nDescription=A hello world\n[Install]\nWantedBy=multi-user.target","enabled":true,"name":"hello.service"},{"dropins":[{"contents":"[Service]\nEnvironment=LOG_LEVEL=trace\n","name":"log_trace.conf"}],"name":"fdo-client-linuxapp.service"}]}}

   After you run the Butane Config YAML file to check and generate the Ignition Config JSON file, you might get warnings when using unsupported fields, like partitions, for example. You can fix those fields and rerun the check.

Procedure

1. Click Create Blueprint in the upper-right corner.

   A dialog wizard with fields for the blueprint name and description opens.

   • On the Details page:

     • Enter the name of the blueprint and, optionally, its description. Click Next.

   • On the Ignition page, complete the following steps:

     • On the Firstboot URL field, enter the URL that points to the Ignition configuration to be fetched during the first boot.
     • On the Embedded Data field, drag or upload the base64 encoded Ignition Configuration file. Click Next.
   • Review the image details and click Create.

Procedure

1. Create a plain text file in the Tom’s Obvious, Minimal Language (TOML) format, with the following content:

   name = "simplified-installer-blueprint"
   description = "Blueprint with Ignition for the simplified installer image"
   version = "0.0.1"
   packages = []
   modules = []
   groups = []
   distro = ""
   
   [customizations.ignition.embedded]
   config = "eyJ --- BASE64 STRING TRIMMED --- 19fQo="

   Where:

   • The name is the name and description is the description for your blueprint.
   • The version is the version number according to the Semantic Versioning scheme.
   • The modules and packages describe the package name and matching version glob to be installed into the image. For example, the package name = "tmux" and the matching version glob is version = "3.3a". Notice that currently there are no differences between packages and modules.

   • The groups are packages groups to be installed into the image. For example groups = "anaconda-tools" group package. If you do not know the modules and groups, leave them empty.

     Warning

     If you want to create a user with Ignition, you cannot use the FDO customizations to create a user at the same time. You can create users using Ignition and copy configuration files using FDO. But if you are creating users, create them using Ignition or FDO, but not both at the same time.

2. Push (import) the blueprint to the image builder server:

   # composer-cli blueprints push blueprint-name.toml

3. List the existing blueprints to check whether the created blueprint is successfully pushed and exists.

   # composer-cli blueprints show blueprint-name

4. Check whether the components and versions listed in the blueprint and their dependencies are valid:

   # composer-cli blueprints depsolve blueprint-name