Add support for azure cloud in trivy

[AkhtarAmir]

Today we support aws cloud scanning in trivy. The intention is to support scanning for Azure cloud as well.

[simar7]

Thanks for starting the discussion @AkhtarAmir. Can you please describe what the user experience would look like? I assume the following:

$ trivy azure

Would scan everything in your azure cloud?

Similar options would work for azure as they do today, for example: --services=<service-name> would target just that particular service?

Feel free to add more details here.

[simar7]

AFAIK with aws, this precedence order is already set and usable via the AWS SDK. So users of the AWS SDK don't have to implement this. I assume it should be the case with Azure SDK as well but this behaviour should be verified.

[AkhtarAmir]

So Azure SDK does not save creds locally, instead it creates access_token and refresh_token so we can't replicate AWS behaviour. I was thinking taking config.json as azure flag and parse creds from it

[simar7]

As discussed offline, @AkhtarAmir will investigate further into how Azure SDK handles auth.

[knqyf263]

I'm unsure if it helps, but we recently did something around Azure auth.
#4489

[AkhtarAmir]

It is helpful. Thanks