NoCloud (seed.iso) cloud-init configuration for Amazon Linux 2023 on KVM and VMware - Amazon Linux 2023
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NoCloud (seed.iso) cloud-init configuration for Amazon Linux 2023 on KVM and VMware

This section covers how to create and use a seed.iso image to configure Amazon Linux 2023 running on KVM or VMware. Because KVM and VMware environments do not have Amazon EC2 Instance Meta Data Service (IMDS), an alternate method of configuring Amazon Linux 2023 is required, and providing a seed.iso image is one of those methods.

The seed.iso boot image includes the initial configuration information that is needed to boot and configure your new virtual machine, such as the network configuration, host name, and user data.

Note

The seed.iso image includes only the configuration information required to boot the VM. It does not include the Amazon Linux 2023 operating system files.

To generate the seed.iso image, you need at least two configuration files, sometimes three:

meta-data

This file typically includes the hostname for the virtual machine.

user-data

This file typically configures user accounts, their passwords, ssh key pairs, and/or access mechanisms. By default, the Amazon Linux 2023 KVM and VMware images create an ec2-user user account. You can use the user-data configuration file to set the password and/or ssh keys for this default user account.

network-config (optional)

This file typically provides a network configuration for the virtual machine which will override the default one. The default configuration is to use DHCP on the first available network interface.

Create the seed.iso disk image

  1. On a Linux or macOS computer, create a new folder named seedconfig and navigate into it.

    Note

    Using Windows or another Operating System to complete these steps is possible, but you will have to find the equivalent tool to mkisofs to complete creating the seed.iso image.

  2. Create the meta-data configuration file.

    1. Create a new file named meta-data.

    2. Open the meta-data file using your preferred editor and add the following, replacing vm-hostname with the host name for the VM: 

      #cloud-config
local-hostname: vm-hostname

    3. Save and close the meta-data configuration file.

  3. Create the user-data configuration file.

    1. Create a new file named user-data.

    2. Open the user-data file using your preferred editor and add the following, making substitutions as needed: 

      #cloud-config
#vim:syntax=yaml
users:
# A user by the name 'ec2-user' is created in the image by default.
  - default
  - name: ec2-user
ssh_authorized_keys:
  - ssh-rsa ssh-key
# In the above line, replace ssh key with the content of your ssh public key.

    3. You can optionally add more user accounts to the user-data configuration file.

      You can specify additional user accounts, their access mechanisms, passwords, and key pairs. For more information about the supported directives, see the upstream cloud-init documentation.

    4. Save and close the user-data configuration file.

  4. (Optional) Create the network-config configuration file.

    1. Create a new file named network-config.

    2. Open the network-config file using your preferred editor and add the following, replacing the various IP addresses with the appropriate ones for your setup. 

      #cloud-config
version: 2
ethernets:
  enp1s0:
    addresses:
      - 192.168.122.161/24
    gateway4: 192.168.122.1
    nameservers:
      addresses: 192.168.122.1
      Note

      cloud-init network configuration provides mechanisms to match against the MAC address of the interface instead of specifying the interface name which can change depending on the VM configuration. This (and more) cloud-init features for network configuration are described in more detail in the upstream cloud-init Network Config Version 2 documentation.

    3. Save and close the network-config configuration file.

  5. Create the seed.iso disk image using the meta-data, user-data, and optional network-config configuration files created in the previous steps.

    Do one of the following, depending on the OS you are creating the seed.iso disk image on.

    • On Linux systems, use a tool such as mkisofs or genisoimage to create the completed seed.iso file. Navigate into the seedconfig folder, and run the following command: 

      $ mkisofs -output seed.iso -volid cidata -joliet -rock user-data meta-data

    • If you use a network-config, include it in the invocation of mkisofs: 

      $ mkisofs -output seed.iso -volid cidata -joliet -rock user-data meta-data network-config

    • On macOS systems, you can use a tool such as hdiutil to generate the finished seed.iso file. Since hdiutil takes a pathname rather than a list of files, the same invocation can be used regardless of if a network-config configuration file has been created or not. 

      $ hdiutil makehybrid -o seed.iso -hfs -joliet -iso -default-volume-name cidata seedconfig/

  6. The resulting seed.iso file can now be attached to your new Amazon Linux 2023 Virtual Machine using a virtual CD-ROM drive for cloud-init to find on first boot and apply the configuration to the system.