This guide covers building custom images for the following operating systems using Packer for deployment in MAAS:
- RHEL 7
- RHEL 8
- CentOS 7
- Oracle Linux 8
- Oracle Linux 9
- VMware ESXi
1. Verify Requirements
You need a machine running Ubuntu 18.04+ or 22.04+ with the ability to run KVM virtual machines. Ensure the following components are available:
| OS | Additional Requirements |
|---|---|
| RHEL 7 | MAAS 2.3+, Curtin 18.1-59+, RHEL 7 DVD ISO |
| RHEL 8 | MAAS 2.3+, Curtin 18.1-59+, RHEL 8 DVD ISO |
| CentOS 7 | MAAS 2.3+, Curtin 18.1-59+ |
| Oracle Linux 8 | MAAS 3.5+, Curtin 23.1+, libnbd-bin, nbdkit, fuse2fs, Oracle Linux 8 DVD ISO |
| Oracle Linux 9 | MAAS 3.5+, Curtin 23.1+, libnbd-bin, nbdkit, fuse2fs, Oracle Linux 9 DVD ISO |
| VMware ESXi | MAAS 2.5+, qemu-kvm, qemu-utils, VMware ESXi ISO |
2. Install Packer
For Ubuntu 18.04+
sudo apt install packer
For Ubuntu 22.04+ (Required for Oracle Linux 8/9)
curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo apt-key add -
sudo apt-add-repository "deb [arch=amd64] https://apt.releases.hashicorp.com $(lsb_release -cs) main"
sudo apt-get update && sudo apt-get install packer
3. Install Dependencies
Install dependencies required for image building:
sudo apt install qemu-utils
For Oracle Linux 8/9 and VMware ESXi, install additional dependencies:
sudo apt install libnbd-bin nbdkit fuse2fs qemu-utils
For VMware ESXi, install Python pip:
sudo apt install pip
4. Get Packer Templates
Clone the Packer templates repository:
git clone https://github.com/canonical/packer-maas.git
5. Download ISO Files
Download the appropriate ISO for your desired OS version and place it in the corresponding subdirectory:
| OS | ISO Location | Subdirectory |
|---|---|---|
| RHEL 7 | RHEL 7 DVD ISO | rhel7 |
| RHEL 8 | RHEL 8 DVD ISO | rhel8 |
| CentOS 7 | Downloaded via template | centos7 |
| Oracle Linux 8 | Oracle Linux 8 DVD ISO | ol8 |
| Oracle Linux 9 | Oracle Linux 9 DVD ISO | ol9 |
| VMware ESXi | VMware ESXi ISO | vmware-esxi |
6. Customize the Image
Modify the Kickstart file to customize the deployment image:
| OS | Kickstart File |
|---|---|
| RHEL 7 | http/rhel7.ks |
| RHEL 8 | http/rhel8.ks |
| CentOS 7 | http/centos7.ks |
| Oracle Linux 8 | http/ol8.ks |
| Oracle Linux 9 | http/ol9.ks |
| VMware ESXi | packer-maas/vmware-esxi/KS.CFG |
Refer to the respective Kickstart documentation for detailed customization options.
7. Optional Proxy Configuration
To use a proxy during the build process:
-
Set the HTTP Proxy:
export HTTP_PROXY=http://your-proxy-server:port -
Modify Kickstart Files:
Add
--proxy=$HTTP_PROXYto lines starting withurlorrepo.
For Oracle Linux 8/9, set the KS_PROXY variable:
export KS_PROXY=$HTTP_PROXY
8. Build the Image
Using the Makefile
Run the following command in the appropriate subdirectory (rhel7, rhel8, centos7, ol8, ol9, vmware-esxi):
make ISO=/PATH/TO/your-iso-file.iso
Manually Using Packer
Alternatively, manually run Packer:
For RHEL 7/8:
sudo PACKER_LOG=1 packer build -var 'iso_path=/PATH/TO/your-iso-file.iso' rhel7.json # or rhel8.json
For CentOS 7:
sudo PACKER_LOG=1 packer build centos7.json
For Oracle Linux 8/9:
packer init .
PACKER_LOG=1 packer build .
For VMware ESXi:
sudo PACKER_LOG=1 packer build -var 'vmware_esxi_iso_path=/PATH/TO/your-esxi-iso-file.iso' vmware-esxi.json
Note: Packer runs in headless mode by default. To view the installation output, connect via VNC or set headless to false.
9. Upload the Image to MAAS
Commands for Each OS
| OS | Upload Command |
|---|---|
| RHEL 7 | maas $PROFILE boot-resources create name='rhel/7-custom' title='RHEL 7 Custom' ... |
| RHEL 8 | maas $PROFILE boot-resources create name='rhel/8-custom' title='RHEL 8 Custom' ... |
| CentOS 7 | maas $PROFILE boot-resources create name='centos/7-custom' title='CentOS 7 Custom' ... |
| Oracle Linux 8 | maas $PROFILE boot-resources create name='ol/8.8' title='Oracle Linux 8.8' ... |
| Oracle Linux 9 | maas $PROFILE boot-resources create name='ol/9.2' title='Oracle Linux 9.2' ... |
| VMware ESXi | maas $PROFILE boot-resources create name='esxi/6.7' title='VMware ESXi 6.7' ... |
10. Verify and Log In
Deploy the image and log in to verify customizations:
| OS | Default Username |
|---|---|
| RHEL 7/8 | cloud-user |
| CentOS 7 | centos |
| Oracle Linux 8/9 | cloud-user |
| VMware ESXi | root |