Terraform Flip-Flop Provider

This is a provider that can be helpful in implementing rolling rotations.

Building The Provider

1. Clone the repository
2. Enter the repository directory
3. Build the provider using the Go install command:

$ go install

Using the provider

Example usage to use time_rotating to trigger automatic rotation of a aws_iam_access_key resource:

resource "aws_iam_user" "rotation" {
  name = "some-user"
}

resource "time_rotating" "rotation" {
  rotation_days = 7
}

resource "flipflop" "rotation" {
  value = time_rotating.rotation.id
}

locals {
  rotation_values = [flipflop.rotation.a, flipflop.rotation.b]
}

resource "null_resource" "rotation" {
  count = length(local.rotation_values)
  triggers = {
    user  = aws_iam_user.rotation.name
    value = local.rotation_values[count.index]
  }
}

resource "aws_iam_access_key" "rotation" {
  count = length(local.rotation_values)
  user  = null_resource.rotation[count.index].triggers.user
}

locals {
  rotated_access_key = aws_iam_access_key.rotation[flipflop.rotation.index]
}

While this is quite verbose, the complication comes from needing to get Terraform to only invalidate one leg of the dependency graph at a time.

Developing the Provider

If you wish to work on the provider, you'll first need Go installed on your machine (see Requirements above).

To compile the provider, run go install. This will build the provider and put the provider binary in the $GOPATH/bin directory.

To generate or update documentation, run go generate.

In order to run the full suite of Acceptance tests, run make testacc.

Note: Acceptance tests create real resources, and often cost money to run.

$ make testacc