azure bootstrap failure on certain regions due to incorrect instance type being used

This still seems to be a problem on a lot of regions, and not limited to bootstrapping

Deploying to e.g. azure/ukwest works fine -

   juju bootstrap azure/ukwest cdk1
   Creating Juju controller "cdk1" on azure/ukwest
   Looking for packaged Juju agent version 2.7.4 for amd64
   Launching controller instance(s) on azure/ukwest...
    - machine-0 (arch=amd64 mem=3.5G cores=1)
   Installing Juju agent on bootstrap instance
   Fetching Juju GUI 2.15.0
   Waiting for address
   Attempting to connect to 192.168.16.4:22
   Attempting to connect to 51.11.120.37:22
   Connected to 51.11.120.37
   Running machine configuration script...
   Bootstrap agent now started
   Contacting Juju controller at 192.168.16.4 to verify accessibility...

   Bootstrap complete, controller "cdk1" is now available
   Controller machines are in the "controller" model
   Initial model "default" added

N.B. This deploys a 'Standard_D1_v2" instance type

Trying the same on the default region (centralus) yields errors:

juju bootstrap azure cdk2

Creating Juju controller "cdk2" on azure/centralus
Looking for packaged Juju agent version 2.7.4 for amd64
Launching controller instance(s) on azure/centralus...
ERROR creating instance failed, destroying: creating deployment "machine-0": resources.DeploymentsClient#CreateOrUpdate: Failure sending request: StatusCode=400 -- Original Error: Code="InvalidTemplateDeployment" Message="The template deployment failed with error: 'The resource with id: '/subscriptions/bf4b9325-b972-4693-b28d-17b3226ab202/resourceGroups/juju-controller-model-4545acce-5105-4207-8566-07258b146404/providers/Microsoft.Compute/virtualMachines/machine-0' failed validation with message: 'The requested size for resource '/subscriptions/bf4b9325-b972-4693-b28d-17b3226ab202/resourceGroups/juju-controller-model-4545acce-5105-4207-8566-07258b146404/providers/Microsoft.Compute/virtualMachines/machine-0' is currently not available in location 'centralus' zones '' for subscription 'bf4b9325-b972-4693-b28d-17b3226ab202'. Please try another size or deploy to a different location or zones. See https://aka.ms/azureskunotavailable for details.'.'."
ERROR bootstrap failed, destroying model: cannot start bootstrap instance: creating virtual machine "machine-0": creating deployment "machine-0": resources.DeploymentsClient#CreateOrUpdate: Failure sending request: StatusCode=400 -- Original Error: Code="InvalidTemplateDeployment" Message="The template deployment failed with error: 'The resource with id: '/subscriptions/bf4b9325-b972-4693-b28d-17b3226ab202/resourceGroups/juju-controller-model-4545acce-5105-4207-8566-07258b146404/providers/Microsoft.Compute/virtualMachines/machine-0' failed validation with message: 'The requested size for resource '/subscriptions/bf4b9325-b972-4693-b28d-17b3226ab202/resourceGroups/juju-controller-model-4545acce-5105-4207-8566-07258b146404/providers/Microsoft.Compute/virtualMachines/machine-0' is currently not available in location 'centralus' zones '' for subscription 'bf4b9325-b972-4693-b28d-17b3226ab202'. Please try another size or deploy to a different location or zones. See https://aka.ms/azureskunotavailable for details.'.'."
^[[A^[[BERRO...

Looks like the valid SKUs are subscription specific sadly.
So unlike other clouds where there's a known list of instances types for regions, this will need to be dynamically determined each time for the given credential in use.

Ah, thanks for that. I think I can document around the specific issues we have by recommending specifying instance types in an overlay, but yes, in general it sucks.

This bug has not been updated in 2 years, so we're marking it Low importance. If you believe this is incorrect, please update the importance.