nested-builder

Usage

Resource deployment

In a Codespace, deploy the builder VM with nested virtualization enabled. Examples are provided for Bicep and Terraform.

# Login for codespaces
az login --use-device-code

# [Option 1] Deploy the builder VM (Bicep)
az deployment sub create -l westus3 -f ./builder/bicep/main.bicep

# [Option 2] Deploy the builder VM (Terraform)
pushd builder/terraform
terraform init
terraform apply
popd

Builder VM configuration

Run configuration scripts to enable the Hyper-V role and configure networking to build nested VMs

az vm run-command invoke --command-id RunPowerShellScript -g builder -n builder --scripts @builder/Configure-Roles.ps1
az vm run-command invoke --command-id RunPowerShellScript -g builder -n builder --scripts @builder/Configure-VM.ps1

Build a VHD image via Packer

RDP to the builder VM and open PowerShell as Administrator. Clone this repo, then use Packer to automate installing Linux from an ISO, configuring it for Azure, and exporting it to a VHD

# Ensure that LF doesn't get converted to CRLF on clone
git config --global core.autocrlf input

# Clone the repo
git clone https://github.com/noelbundick-msft/nested-builder

# Build a CentOS 6.3 image
cd nested-builder/centos63
packer build centos63.pkr.hcl

# Use Managed Identity for azcopy
azcopy login --identity

# Upload the VHD to blob storage
azcopy copy '.\output-centos63\Virtual Hard Disks\packer-centos63.vhd' https://builder34n3pk.blob.core.windows.net/images/centos63.vhd

Create the image in Azure

In your codespace, create an image from the exported VHD

az image create -g images -n centos63 --os-type Linux --source https://builder34n3pk.blob.core.windows.net/images/centos63.vhd

Validate the image

In your codespace, create a VM from the image

IMAGE_ID=$(az image show -g images -n centos63 --query id -o tsv)
az group create -n test1 -l westus3
az vm create -n test1 -g test1 --image $IMAGE_ID

Customize a child image

In your codespace, use Packer to further customize the image. This will create a new VM in Azure, run a customization script, then capture the disk entirely in Azure without the need to use the Hyper-V nested builder

cd centos63-custom/
packer build ./centos63-custom.pkr.hcl

Overview

• /builder - stands up a builder VM with
  • Nested virtualization
  • Just-in-time RDP access
  • Auto-shutdown
  • Configure-Roles.ps1
    • Install Hyper-V and DHCP
  • Configure-VM.ps1
    • Configure a network / NAT
    • Setup DHCP
    • Install chocolatey + latest versions of:
      • Packer
      • azcopy
      • git
• /centos63 - configuration to create a CentOS 6.3 image via Packer
  • centos63.pkr.hcl - the Packer configuration with
    • Pull/cache an ISO
    • Export to legacy VHD format for Azure
    • Serve a directory via HTTP
    • Automate pressing the OK button for unsupported hardware
    • ks.cfg - RHEL/CentOS OS installation
      • Set input/locale
      • Use cdrom (ISO) sources
      • Install Linux Integration Services (needed for Packer SSH)
    • postinstall.sh - install script run by Packer
      • Customize kernel params
      • Update repos to point to archive.org for CentOS 6.3
      • Add OpenLogic repo
      • Configure networking
      • Deprovision to prepare for Azure
• /centos63-custom - sample to create a further customized image using the Azure ARM builder from the CentOS 6.3 base