aws_instance diff mismatch when tags drift

[jeevanullas]

Hi guys,

Great stuff. We got terraform going on Eucalyptus. Tried to change a plan by changing the EMI (AMI) ID and applying it. Found a problem. Logs at

https://gist.github.com/jeevanullas/e15beaa8c4879acc7e6e

If I apply the plan again now, it does create a new instance with the new EMI ID. Thanks for looking at it.

Cheers,
Deependra

[phinze]

Hi there - great to hear that TF is up and running on Eucalyptus!

Here's the relevant bit:

2015/04/30 12:55:17 [ERROR] aws_instance.example: diffs didn't match
2015/04/30 12:55:17 [ERROR] aws_instance.example: reason: attribute mismatch: tags.#
2015/04/30 12:55:17 [ERROR] aws_instance.example: diff one: *terraform.InstanceDiff{Attributes:map[string]*terraform.ResourceAttrDiff{"public_dns":*terraform.ResourceAttrDiff{Old:"euca-109-104-120-42.eucalyptus.emea.eucalyptus.com", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "subnet_id":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "public_ip":*terraform.ResourceAttrDiff{Old:"109.104.120.42", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "private_dns":*terraform.ResourceAttrDiff{Old:"euca-10-30-2-16.eucalyptus.internal", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "placement_group":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "private_ip":*terraform.ResourceAttrDiff{Old:"10.30.2.16", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "root_block_device.#":*terraform.ResourceAttrDiff{Old:"0", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "vpc_security_group_ids.#":*terraform.ResourceAttrDiff{Old:"0", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "availability_zone":*terraform.ResourceAttrDiff{Old:"emea-az-01", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "ephemeral_block_device.#":*terraform.ResourceAttrDiff{Old:"0", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "key_name":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "tags.euca:node":*terraform.ResourceAttrDiff{Old:"10.30.0.219", New:"", NewComputed:false, NewRemoved:true, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "ami":*terraform.ResourceAttrDiff{Old:"emi-d1a30feb", New:"emi-a702b3b6", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Type:0x0}, "ebs_block_device.#":*terraform.ResourceAttrDiff{Old:"0", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "tenancy":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "instance_type":*terraform.ResourceAttrDiff{Old:"m1.large", New:"m1.large", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "security_groups.#":*terraform.ResourceAttrDiff{Old:"1", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "tags.#":*terraform.ResourceAttrDiff{Old:"1", New:"0", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}}, Destroy:false, DestroyTainted:false}
2015/04/30 12:55:17 [ERROR] aws_instance.example: diff two: *terraform.InstanceDiff{Attributes:map[string]*terraform.ResourceAttrDiff{"ami":*terraform.ResourceAttrDiff{Old:"", New:"emi-a702b3b6", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Type:0x0}, "public_dns":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "private_ip":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Type:0x0}, "root_block_device.#":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "availability_zone":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Type:0x0}, "ebs_block_device.#":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "key_name":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Type:0x0}, "ephemeral_block_device.#":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "public_ip":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "private_dns":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "placement_group":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Type:0x0}, "subnet_id":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Type:0x0}, "vpc_security_group_ids.#":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "security_groups.#":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:false, Type:0x0}, "instance_type":*terraform.ResourceAttrDiff{Old:"", New:"m1.large", NewComputed:false, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Type:0x0}, "tenancy":*terraform.ResourceAttrDiff{Old:"", New:"", NewComputed:true, NewRemoved:false, NewExtra:interface {}(nil), RequiresNew:true, Type:0x0}}, Destroy:false, DestroyTainted:false}

Looks like something to do with tags. Does the config you're using for this instance set any tags? If you change whether it sets tags does that change the problem?

If you can include a config snippet that generates the error that would be helpful.

[jeevanullas]

Thanks for quick response. The config is below:

provider "aws" {
    access_key = ""
    secret_key = ""
    region = "eucalyptus"
}

resource "aws_instance" "example" {
    ami = "emi-a702b3b6"
    instance_type = "m1.large"
}

[phinze]

@jeevanullas I'm curious - if you add tags to the instance declaration - do you get the same error?

Also, are you using 0.4.2 here? Do you have the ability to try out a build from master? https://github.com/hashicorp/terraform/blob/master/CONTRIBUTING.md#setting-up-go-to-work-on-terraform

[jeevanullas]

Hi @phinze apologies for the delay. I tried with a custom tag in my declaration and it worked like a charm. This was my config:

provider "aws" {
    access_key = ""
    secret_key = ""
    region = "eucalyptus"
}

resource "aws_instance" "example" {
    ami = "emi-d1a30feb"
    instance_type = "m1.large"
    tags {
        Name = "myinstance"
    }
}

$ terraform version
Terraform v0.5.0-dev (68df1e6e4dc2bafe8e80c134b3c39c8ee7d116a1+CHANGES)

I saw that in the case of failure I had a tag on the instance , this was the output of terraform show after I modified the config:

tags.#:                   "1" => "0"
tags.euca:node:    "10.30.0.219" => ""

I wonder if this creates problem? Note that on Eucalyptus when you launch an instance the system creates a tag and and assign a value to it. The tag 'euca:node' has a value set to the IP address of the machine running the instance.

In case of the successful the plan was

tags.#:                   "2" => "1"
tags.Name:            "myinstance" => "myinstance"
tags.euca:node:     "10.30.0.215" => ""

Looks like we cannot have tags.# = 0? Please let me know if you have any further questions. Thanks again for all your assistance.

Cheers,
Deependra

[phinze]

Yup this was my hunch - it seems like Eucalyptus creates an implicit tag (euca:node) when you create an instance. I believe we should be able to get this sorted out within the AWS instance provider.

[catsby]

I've reproduced this on AWS as well.
Steps:

1. apply this:

provider "aws" {
  region="us-west-2"
}

resource "aws_instance" "nat" {
  ami = "ami-21f78e11"
  instance_type = "t1.micro"
}

2. Go to https://console.aws.amazon.com , find the instance, and apply a Tag

3. Change config to this:

provider "aws" {
  region="us-west-2"
}

resource "aws_instance" "nat" {
  ami = "ami-dfc39aef"
  instance_type = "t2.micro"
}

4. plan:

$ plan
Refreshing Terraform state prior to plan...

aws_instance.nat: Refreshing state... (ID: i-1dc318ea)

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.

Your plan was also saved to the path below. Call the "apply" subcommand
with this plan file and Terraform will exactly execute this execution
plan.

Path: create.tfplan

-/+ aws_instance.nat
    ami:                      "ami-21f78e11" => "ami-dfc39aef" (forces new resource)
    availability_zone:        "us-west-2b" => "<computed>"
    ebs_block_device.#:       "0" => "<computed>"
    ephemeral_block_device.#: "0" => "<computed>"
    instance_type:            "t1.micro" => "t2.micro" (forces new resource)
    key_name:                 "" => "<computed>"
    placement_group:          "" => "<computed>"
    private_dns:              "ip-172-31-30-19.us-west-2.compute.internal" => "<computed>"
    private_ip:               "172.31.30.19" => "<computed>"
    public_dns:               "ec2-52-24-125-143.us-west-2.compute.amazonaws.com" => "<computed>"
    public_ip:                "52.24.125.143" => "<computed>"
    root_block_device.#:      "1" => "<computed>"
    security_groups.#:        "0" => "<computed>"
    subnet_id:                "subnet-b4b122d1" => "<computed>"
    tags.#:                   "1" => "0"
    tags.nerg:                "dorb" => ""
    tenancy:                  "default" => "<computed>"
    vpc_security_group_ids.#: "1" => "<computed>"

5. `apply:

* 1 error(s) occurred:

* aws_instance.nat: diffs didn't match during apply. This is a bug with Terraform and should be reported.

• Full apply gist here

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