Support multiple Key Vaults in one instance of AcmeBot

[gummigroda]

We'ed like support for multiple Key Vaults from one instance of AcmeBot, as we have the need to put certificates in different KV's and don't want to install one AcmeBot environment for each KV.

The idea would be:

1. As the Managed Identity (UAMI or System) assigned to AcmeBot, query ARG for Key Vaults:

resources
| where type =~ 'microsoft.keyvault/vaults'
| project name,resourceGroup, id

2. Iterate through the received dataset and "manage/monitor" the certificates as current implementation.

• This would allow for distributed certificate management without the downside of "role assignment spree" or "scripted certificate replication automation".

• The ARG dataset returned is dependent on the permissions given to the MI assigned to AcmeBot, which makes it easy to add and remove Key Vaults that AcmeBot should handle.

• (The same approach could be used for the subscription ID's needed for the Azure handled DNS Zones, as some might not store them in the same subscription. Replaces Acmebot__AzureDns__SubscriptionId environment variable)

[greatlook2048]

I also desire this feature, and ideally we could set what KV the certificate is sent to when we go through the Issue Certificate dialog Advanced Options.

[gummigroda]

@shibayan, would this be possible or is it a "large" redesign?