Terraform conditional block based on environment

问题:

I'm looking at using the new conditionals in Terraform to basically turn a config block on or off depending on the evnironment.

Here's the block that I'd like to make into a conditional, if, for example I have a variable to turn on for production.

access_logs {
    bucket = "my-bucket"
    prefix = "${var.environment_name}-alb"
}

I think I have the logic for checking the environment conditional, but I don't know how to stick the above configuration into the logic.

"${var.environment_name == "production" ? 1 : 0 }"

Is it possible to turn the access_logs block on and off via the environment_name variable? If this is not possible, is there a workaround?

回答1:

In the current terraform, the if statement is only a value and can not be used for the block.

There is a workaround in this case. You can set the enabled attribute of the access_log block to false. Note that this is not a general solution but can only be used with the access_log block.

access_logs {
    bucket  = "my-bucket"
    prefix  = "${var.environment_name}-alb"
    enabled = "${var.environment_name == "production" ? true : false }"
}

See also:

• https://www.terraform.io/docs/providers/aws/r/elb.html#access_logs
• https://www.terraform.io/docs/providers/aws/r/alb.html#access_logs
• https://github.com/hashicorp/terraform/pull/11120

回答2:

Conditionals in terraform are currently only to be used to determine a value, not to be used as an if statement wrapping a block.

And you can also use conditionals to determine a value based on some logic.

https://www.terraform.io/docs/configuration/interpolation.html#conditionals