[Enhancement] Allow for custom network config YAML file

[zanewgray]

For new VM deployments that require a more customized network configuration, could the provisioning script be modified to accept a flag like "-CustomNetAutoconfigYamlFile" so that the NetAutoconfig is not automatically generated?

Use case examples:

• NGINX reverse proxy that requires multiple, static IP addresses on a single interface
• Setting custom MTU for low-bandwidth remote sites or high bandwidth datacenters
• Setting IPv6-only network configurations

Options tried: When attempting to use the "-CustomUserDataYamlFile" with a write_files section for editing /etc/netplan/50-cloud-init.yaml, I found that the script overwrites this with the data generated by the NetAutoconfig portion of the script.

There may already be a means of accomplishing the above through the use of one or more of the flags. If so, then this issue may simply be a request for documentation.

Thanks for your amazing work!

[samstagern]

I would like if the code to generate the cloud-init yaml would be in a separate script and function.

[schtritoff]

@zanewgray You can provide your own cloud-init file with your custom variables that ignores NetAutoconfig part and completely different networking configuration.

This is the line where you replace cloud-init yaml with a custom one;

hyperv-vm-provisioning/New-HyperVCloudImageVM.ps1

Line 741 in 4751393

$userdata = $ExecutionContext.InvokeCommand.ExpandString( $(Get-Content $CustomUserDataYamlFile -Raw) ) # parse variables

[zanewgray]

Thanks @schtritoff. I have been using the -CustomUserDataYamlFile option for most of my VM deployments on Hyper-V. In fact, it is the main selling point for my using your deployment script.

My generic userdata.yaml file is pretty large. So, for testing, I created a custom net-test.yaml that only does a few things:

• sets a password for the ubuntu user
• writes a /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg file (to disable the automatic network config)
• writes a /etc/netplan/50-cloud-init.yaml file that sets a static IP, default route, and name servers

I then used the -CustomUserDataYamlFile "net-test.yaml" option with the VM creation script, and found that the 50-cloud-init.yaml file had the expected, static IP values.

My next step is to dive into my original userdata.yaml file and see what operation is causing the /etc/netplan/50-cloud-init.yaml file to either not be written, or to be overwritten on reboot (almost as if my netplan apply in my runcmd section is not doing its job).

Regardless, thank-you for verifying that the NetAutoconfig can be superseded by cloud-init entries!

You can close this issue as resolved.