Issue with plan if not capacity reservation provided

[savroman]

Description

Running terraform plan cased the issue

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⚠️ Note

Before you submit an issue, please perform the following first:

1. Remove the local .terraform directory (! ONLY if state is stored remotely, which hopefully you are following that best practice!): rm -rf .terraform/
2. Re-initialize the project root to pull down modules: terraform init
3. Re-attempt your terraform plan or apply and check if the issue still persists

Done! But not helps.

Versions

• Module version: 4.1.3
• Terraform version: 1.2.6
• Provider version(s): 4.23.0

Reproduction Code [Required]

module "ec2_data" {
  # https://registry.terraform.io/modules/terraform-aws-modules/ec2-instance/aws/latest
  source  = "terraform-aws-modules/ec2-instance/aws"
  version = "~> 4.0"
  # insert the 10 required variables here
  create = true

  name                        = "${local.pre-fix}"
  ami                         = data.aws_ssm_parameter.ubuntu_latest_ami_arm64.value
  instance_type               = "t4g.micro"
  cpu_credits                 = "unlimited"
  subnet_id                   = module.vpc.public_subnets[0]
  vpc_security_group_ids      = [aws_security_group.ssh.id]
  associate_public_ip_address = true
  ebs_optimized               = true
  iam_instance_profile        = aws_iam_instance_profile.ec2.name
  key_name                    = aws_key_pair.ec2.key_name
  user_data                   = null
  disable_api_termination     = true
  monitoring                  = false
  root_block_device = [
    {
      volume_type = "gp2"
      volume_size = 50
    }
  ]
  
}

Steps to reproduce the behavior:
terraform init
terraform plan

Expected behavior

plan output

Actual behavior

 Error: Invalid combination of arguments
│ 
│   with module.ec2_data.aws_instance.this[0],
│   on .terraform/modules/ec2_data/main.tf line 7, in resource "aws_instance" "this":
│    7: resource "aws_instance" "this" {
│ 
│ "capacity_reservation_specification.0.capacity_reservation_target": one of
│ `capacity_reservation_specification.0.capacity_reservation_preference,capacity_reservation_specification.0.capacity_reservation_target`
│ must be specified

Terminal Output Screenshot(s)

Additional context

Downgrade to 4.1.2 fixes the issue

[schniber]

I was able to reproduce.

In fact the default value of the capacity_reservation_specification should remain null instead of {}

@bryantbiggs : I can revert this back to what it was originally

[bryantbiggs]

let me take a deeper look locally

[vsem-cw]

ran into the same error today and confirmed @savroman's note with downgrading to 4.1.2 worked for me as well.

[qxmips]

looks like the module testing should be improved.

[bryantbiggs]

looks like the module testing should be improved.

sponsorships are always welcomed so we can dedicate more time

[antonbabenko]

This issue has been resolved in version 4.1.4 🎉

[github-actions]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues. If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.