add instance refresh preferences

[scott-doyland-burrows]

what

Adds skip_matching and auto_rollback to the instance refresh preferences.

Allows the instance refresh preferences to be optional. If the values are not set in the calling module, then the default values are used as per:

https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_group#instance_refresh

why

Previously it was not possible to set the skip_matching and auto_rollback.

It was also not possible to omit preferences from the calling module and just use the defaults instead.

With this change we can now set preferences and/or omit preferences that we wish to use the defaults for.

The change should not cause any diffs in current infrastructure.

references

https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/autoscaling_group#instance_refresh

examples

It is now possible to use something such as this to use defaults:

  instance_refresh = ({
    strategy = "Rolling"
  })

or this to override certain defaults:

  instance_refresh = ({
    strategy = "Rolling"
    preferences = ({
      min_healthy_percentage = 50
      skip_matching          = true
    })
    triggers = ["tags"]
  })

[goruha]

@scott-doyland-burrows How about making preferences also optional?

[Gowiem]

@scott-doyland-burrows this looks good and we'd be happy to get it merged. Can you please do the following and push the changes?

make init
make readme

Thanks!

[scott-doyland-burrows]

I have run make init and make readme from the root of the repo and pushed the chanes.

[Gowiem]

/terratest

[Gowiem]

Ah @scott-doyland-burrows -- can you update https://github.com/cloudposse/terraform-aws-ec2-autoscale-group/blob/main/versions.tf#L2 to require 1.3+? Otherwise someone could have 1.0 or 1.1 pinned, try to use this module, and then it'll break on optional.

[scott-doyland-burrows]

Ah @scott-doyland-burrows -- can you update https://github.com/cloudposse/terraform-aws-ec2-autoscale-group/blob/main/versions.tf#L2 to require 1.3+? Otherwise someone could have 1.0 or 1.1 pinned, try to use this module, and then it'll break on optional.

I have made the change.

[Gowiem]

/terratest

[Gowiem]

Ah apologies @scott-doyland-burrows -- Can you run the make readme again and commit / push the results? The change to the required TF version causes changes in our README.

[scott-doyland-burrows]

Ah apologies @scott-doyland-burrows -- Can you run the make readme again and commit / push the results? The change to the required TF version causes changes in our README.

I have run:
make init and make readme

[Gowiem]

/terratest

Changes have been addressed