By using a set for the availability zones, you can use things like
`availability_zones = ["${aws_instance.web.*.availability_zone}"]`
where is very likely multiple of the same zones will be added to the
set. If you use a list here, the list will say it’s changed (even if
you add the same zone) which will force a new resource.
The resource is build so it can attach and detach the Internet Gateway
from a VPC, but as the schema has `Required` and `ForceNew` both set
to `true` for the vpc_id field it will never use these capabilities.
This is a refactored solution for PR #616. Functionally this is still
the same change, but it’s implemented a lot cleaner with less code and
less changes to existing parts of TF.
Running the tests without these changes results in this error first:
```
--- FAIL: TestAccAWSNetworkAclsOnlyIngressRulesChange (24.92 seconds)
testing.go:121: Step 0 error: Check failed: Invalid number of ingress
entries found; count = %!s(int=3)
FAIL
exit status 1
FAIL github.com/hashicorp/terraform/builtin/providers/aws 24.974s
```
And after fixing that one you also get a few unexpected values due to
an expected order mismatch between the items in the set versus the
items in the config.
Those are also fixed, so the test is passing now.
Otherwise it is impossible to get simple configurations with the
"default" routing table, which is only the "local" route.
The following contents of main.tf expose the bug, and boots an instance
fine after this patch is applied:
variable aws_access_key {}
variable aws_secret_key {}
variable aws_ubuntu_ami {}
provider "aws" {
access_key = "${var.aws_access_key}"
secret_key = "${var.aws_secret_key}"
region = "us-east-1"
}
resource "aws_vpc" "default" {
cidr_block = "10.0.0.0/20"
}
resource "aws_route_table" "private" {
vpc_id = "${aws_vpc.default.id}"
# Note the lack of "route" sub-key here.
}
resource "aws_subnet" "private" {
vpc_id = "${aws_vpc.default.id}"
cidr_block = "10.0.1.0/24"
}
resource "aws_route_table_association" "private" {
subnet_id = "${aws_subnet.private.id}"
route_table_id = "${aws_route_table.private.id}"
}
# Demonstrate an instance can be booted fine in this fashion.
resource "aws_instance" "sample" {
ami = "${var.aws_ubuntu_ami}"
instance_type = "t2.micro"
subnet_id = "${aws_subnet.private.id}"
}
terraform.tfvars for completeness:
aws_access_key = "..."
aws_secret_key = "..."
# A public Trusty AMI
aws_ubuntu_ami = "ami-9aaa1cf2"
Sander van Harmelen