Desired state image building and publishing

Create a VM image and publish it to a image gallery from a single file

 _______________________________
< Desired state managed images! >
 -------------------------------
        \   ^__^
         \  (oo)\_______
            (__)\       )\/\
                ||----w |
                ||     ||

Architecture

Features

• Bootstrap packer and ansible from a single desired state
• Automated building of images and publishing
• Supports Windows and Ubuntu images
• Data as Config driven (DaC)

Tooling

Developed with the following tool versions

• Ansible version 2.9.97
• Packer version 1.8.0
• Python version 3.10.0

Create VMSS

After an image has been published to the compute gallery you can create an VMSS from it. Make sure that the following settings are used

• Add VMSS to the correct VNET/subnet
• Autoscaling settings must be set to "manual" if you want to use VMSS as a self-hosted DevOps agent

How does it work?

1. Everything from the desired_state.yaml file
2. This file is converted by templater.py to Hasicorp Packer HCL templates for IaC image provisioning + Ansible playbook for OS level Config-as-Code
3. CI pipeline runs everything in sequence

How to use

Manually

1. Update desired_settings.yaml
2. Run templater.py (this will create 3 files; scripts/pre-processor-img.sh, build_config/playbook.yaml & builds/azure-vmss.pkr.hcl)
3. Execute scripts/pre-processor-img.sh with bash (this will create an image definition in the compute gallery specified in desired_settings.yaml )
4. Run the builds/azure-vmss.pkr.hcl file with packer

From CI

1. Create a pipeline from the ci/azure-pipelines.yaml file
2. Change the service_connection variable value to an existing service connection
3. Update Update desired_settings.yaml
4. e voilà

TODO

• Create reference docs for desired_state.yaml

Important links

1. Creating VMSS based self hosted Azure DevOps agents: https://docs.microsoft.com/en-us/azure/devops/pipelines/agents/scale-set-agents?view=azure-devops