Adding a root_block_device forces resource refresh in AWS

[jaxxstorm]

I've added a root block device to an ec2 resource

root_block_device {
    device_name = "/dev/sda"
    volume_type = "standard"
    volume_size = 50
  }

This seems to cause a resource refresh each time:

ami:                                       "ami-55d14d22" => "ami-55d14d22"
    availability_zone:                         "eu-west-1a" => "<computed>"
    block_device.#:                            "1" => "<computed>"
    instance_type:                             "m3.xlarge" => "m3.xlarge"
    private_dns:                               "ip-172-24-1-32.eu-west-1.compute.internal" => "<computed>"
    private_ip:                                "172.24.1.32" => "<computed>"
    public_dns:                                "" => "<computed>"
    public_ip:                                 "" => "<computed>"
    root_block_device.#:                       "0" => "1"
    root_block_device.0.delete_on_termination: "" => "1" (forces new resource)
    root_block_device.0.device_name:           "" => "/dev/sda" (forces new resource)
    root_block_device.0.iops:                  "" => "<computed>"
    root_block_device.0.volume_size:           "" => "50" (forces new resource)
    root_block_device.0.volume_type:           "" => "standard" (forces new resource)
    security_groups.#:                         "1" => "1"
    security_groups.1730728398:                "sg-b1c9b0d4" => "sg-b1c9b0d4"
    subnet_id:                                 "subnet-7eb82a1b" => "subnet-7eb82a1b"
    tenancy:                                   "default" => "<computed>"

[phinze]

Thanks for the report - I'll take a look at this sometime today.

[jaxxstorm]

@phinze any love?

[phinze]

Whoops sorry - dropped the ball on this. I'm doing my best to finish landing the beast that is #1045 which I'll make sure takes care of this issue. 👍

[phinze]

@jaxxstorm actually, looking more closely at your output - the root device is typically /dev/sda1 - if you change the device_name to that, does the persistent refreshing stop?

[jaxxstorm]

@phinze, afraid not :(

* Error launching source instance: logicalType cannot be modified on root device
Error applying plan:

1 error(s) occurred:

* 1 error(s) occurred:

* 1 error(s) occurred:

* 1 error(s) occurred:

* Error launching source instance: logicalType cannot be modified on root device

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.

[phinze]

@jaxxstorm now that #1045 has finally landed - can you give this another shot for me?

[jaxxstorm]

@phinze initial checks seem to have fixed this completely! Thanks a bunch! I'll close this out

[ghost]

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.

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