[Bug]: some smaller instance types can be provisioned only with resources, not with instance_types

[greaber]

Steps to reproduce

Try to apply a configuration with the specification

instance_types:
  - t2.small

Actual behaviour

It doesn't work (no offers are shown)

Expected behaviour

It would work. This seems like a bug because you can provision t2.small instances by removing the instance_types constraint and using

resources:
  memory: 2GB
  cpu: 1

dstack version

0.18.29

Server logs

No response

Additional information

No response

[r4victor]

@greaber, thanks for reporting. We'll look into it.

Possibly related to #2067.

[r4victor]

The issue takes place because the default resources are cpu: 2.. and memory: 8GB.., and the resources are taken into account even if instance_types is specified. To get the behavior expected by @greaber, resources have to be ignored if instance_types is specified. This makes sense, but we need to ensure there is no important case when users specify both resources and instance_types.

Another solution would be to ignore only default resources when users specify instance_types, and if users specify resources explicitly, then take them into account as well.