Add support for Azure CLI authentication in addition to Service Principal

[dmytrosklyarov]

Hi team,

While reviewing the image generation process (specifically build-image.ps1 in images.CI/linux-and-win), I noticed that the current implementation relies entirely on explicit Service Principal credentials (client_id, client_secret, tenant_id) for authenticating with Azure.

This is reflected in the Packer templates such as ubuntu-22.04.pkr.hcl, where those values are required.

I’d like to propose adding support for Azure CLI-based authentication (use_azure_cli_auth = true), which Packer supports out of the box. This would allow contributors and CI pipelines that already use az login to avoid managing separate SP credentials.

Key benefits:
• Better local development experience (especially for contributors)
• Simplifies credential management in some CI/CD environments
• Still allows fallback to SP-based auth for full control and automation

Suggestion:
• Add a new optional parameter (e.g. use_cli_auth) in the Packer templates and build-image.ps1 script.
• Based on this flag, switch between client_id/client_secret and use_azure_cli_auth = true.
• Default to current behavior for backward compatibility.

Would appreciate feedback from the maintainers on feasibility and interest in this enhancement.

Thanks!

[subir0071]

Hello @dmytrosklyarov - We are looking into the feasibility of this implementation

[dmytrosklyarov]

Hello @subir0071, thanks for the feedback. Looking forward to have this request prioritized and implemented.