terraform output variablesで複数の値を返すtips

俺です。

terraformのoutput variablesの戻り値はsingle valueです。
aws_instanceリソース内でEC2を複数台起動して、それぞれのパラメータをoutputで返す場合は、
count数分のoutputを記述しないといけません。

間違い

• ec2.tf

resource "aws_instance" "fueruwakame" {
  ami = "${lookup(var.fueruwakame, "ami")}"
  ..省略..
  private_ip = "172.16.10.${count.index+21}"
  root_block_device {
      volume_type = "${lookup(var.fueruwakame,"root_block_device")}"
      volume_size = "${lookup(var.fueruwakame,"root_block_device_size")}"
  }
  count = "9"
  tags {
    Name  = "fueruwakame${count.index + 1}-${aws_subnet.private-1c-subnet.availability_zone}"
    Role = "db"
    Service = "fueruwakame"
  }
}

output "fueruwakame_private_ips" {
    value = "${aws_instance.fueruwakame.*.private_ip}"
}

orenomac$ terraform plan

Errors:

  * 1 error(s) occurred:

* module root: 1 error(s) occurred:

* output 'fueruwakame_private_ips': multi-variable must be in a slice

汚いけど一つのoutput variableで複数の値を返す方法

あんま綺麗じゃないけどjoin()を使ってしまえばOKです。

• ec2.tf

resource "aws_instance" "fueruwakame" {
  ami = "${lookup(var.fueruwakame, "ami")}"
  ..省略..
  private_ip = "172.16.10.${count.index+21}"
  root_block_device {
      volume_type = "${lookup(var.fueruwakame,"root_block_device")}"
      volume_size = "${lookup(var.fueruwakame,"root_block_device_size")}"
  }
  count = "9"
  tags {
    Name  = "fueruwakame${count.index + 1}-${aws_subnet.private-1c-subnet.availability_zone}"
    Role = "db"
    Service = "fueruwakame"
  }
}

output "fueruwakame_private_ips" {
  value = "${join(",",aws_instance.fueruwakame.*.private_ip)}"
}

• apply

orenomac$ terraform apply
Outputs:

  fueruwakame_private_ips   = 172.16.10.21,172.16.10.22,172.16.10.23,172.16.10.24,172.16.10.25,172.16.10.26,172.16.10.27,172.16.10.28,172.16.10.29

多分他にも方法あるはずー。

おわり。