Render notification_topic_arn when exporting ElastiCache clusters

[mozamimy]

I think it's good to render notification_topic_arn on .tf file and .tfstate file. Because I'm using terraforming with Terraform CLI tool with import subcommand.

In that situation, I work according to the below instructions.

• Execute terraforming ecc
• Cut and paste (or process the output by a script) a target cluster TF configuration to a new .tf file.
• Run terraform import module.elasticache_redis.aws_elasticache_cluster.foo foo to import the actual resource into tfstate file.
• I confirm that there are no diffs by run terraform plan command.

If the actual resource has a notification configuration, then the terrafrom plan generates the following output.

An execution plan has been generated and is shown below.
Resource actions are indicated with the following symbols:
  ~ update in-place

Terraform will perform the following actions:

  ~ module.elasticache_redis.aws_elasticache_cluster.foo
      notification_topic_arn: "arn:aws:sns:ap-northeast-1:123456789012:bar" => ""


Plan: 0 to add, 1 to change, 0 to destroy.

I’d like the output of terraforming to eliminate diffs after run terraform import. What do you think about this?

I'm using terraforming with the following environment.

• macOS
• ruby 2.5.3p105
• Terraform v0.11.10 with provider.aws v1.39.0

[coveralls]

Coverage remained the same at 100.0% when pulling 92f101d on mozamimy:elasticache-cluster-notify into 1ba96b9 on dtan4:master.

[dtan4]

Sorry for the late review 🙇

I’d like the output of terraforming to eliminate diffs after run terraform import. What do you think about this?

I agree with this 👍

[dtan4]

LGTM 👍 It works with the current master (44b4bdd)

[mozamimy]

Thank you!