gistfile1.txt

:tf-testing (master)$ terraform show terraform.tfstate
aws_instance.example:
  id = i-5a8e9471
  ami = ami-408c7f28
  availability_zone = us-east-1c
  instance_type = t1.micro
  key_name =
  private_dns = ip-172-31-23-101.ec2.internal
  private_ip = 172.31.23.101
  public_dns = ec2-54-210-135-203.compute-1.amazonaws.com
  public_ip = 54.210.135.203
  security_groups.# = 1
  security_groups.0 = default
  subnet_id = subnet-c3e8f1b7
:tf-testing (master)$ terraform plan
Refreshing Terraform state prior to plan...

aws_instance.example: Refreshing state... (ID: i-5a8e9471)

The Terraform execution plan has been generated and is shown below.
Resources are shown in alphabetical order for quick scanning. Green resources
will be created (or destroyed and then created if an existing resource
exists), yellow resources are being changed in-place, and red resources
will be destroyed.

Note: You didn't specify an "-out" parameter to save this plan, so when
"apply" is called, Terraform can't guarantee this is what will execute.

-/+ aws_instance.example
    ami:               "ami-408c7f28" => "ami-aa7ab6c2" (forces new resource)
    availability_zone: "us-east-1c" => "<computed>"
    key_name:          "" => "<computed>"
    private_dns:       "ip-172-31-23-101.ec2.internal" => "<computed>"
    private_ip:        "172.31.23.101" => "<computed>"
    public_dns:        "ec2-54-210-135-203.compute-1.amazonaws.com" => "<computed>"
    public_ip:         "54.210.135.203" => "<computed>"
    security_groups:   "" => "<computed>"
    subnet_id:         "subnet-c3e8f1b7" => "<computed>"


:tf-testing (master)$ terraform apply
aws_instance.example: Refreshing state... (ID: i-5a8e9471)
aws_instance.example: Destroying...
aws_instance.example: Destruction complete
aws_instance.example: Modifying...
  ami: "ami-408c7f28" => "ami-aa7ab6c2"
aws_instance.example: Error: Error launching source instance: The parameter groupName cannot be used with the parameter subnet (InvalidParameterCombination)
Error applying plan:

1 error(s) occurred:

* Error launching source instance: The parameter groupName cannot be used with the parameter subnet (InvalidParameterCombination)

Terraform does not automatically rollback in the face of errors.
Instead, your Terraform state file has been partially updated with
any resources that successfully completed. Please address the error
above and apply again to incrementally change your infrastructure.