Provide a default for the autoscaling min/max resource

[tobio]

Description

This fixes an issue when specifying an autoscaling min/max when there is no corresponding min/max defined in the deployment template.

We're unable to specify a default in the Terraform schema since the resource attributes are Computed. Instead we define a default in code.

Related Issues

Fixes #401

Motivation and Context

How Has This Been Tested?

Unit tests

Manually with:

resource "ec_deployment" "staging" {
  region                 = "eu-west-1"
  deployment_template_id = "aws-storage-optimized"
  version = "7.17.3"

  elasticsearch {
    topology {
      id         = "hot_content"
      size       = "2g"
      zone_count = 3

      autoscaling {
        max_size = "8g"
      }
    }

    topology {
      id         = "warm"
      size       = "2g"
      zone_count = 2

      autoscaling {
        max_size = "15g"
        min_size = "4g"
      }
    }
  }
}

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (improves code quality but has no user-facing effect)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation

Readiness Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed

[mieciu]

I think it might be worth placing a short comment on why we need this method

[mieciu]

Minor nit about the comment, but that's definitely good to go as it is 👍