aws_route_table bug with ignore_changes - "diffs didn't match during apply"

[carlsverre]

All output summarized here: https://gist.github.com/carlsverre/f50395eaee55952d95ed

Here is the repro (also in the gist):

provider "aws" {
    region = "us-east-1"
}

resource "aws_vpc" "default" {
    cidr_block = "172.17.0.0/24"
}

resource "aws_subnet" "default" {
    vpc_id = "${aws_vpc.default.id}"
    cidr_block = "172.17.0.0/24"
}

resource "aws_internet_gateway" "default" {
    vpc_id = "${aws_vpc.default.id}"
}

resource "aws_route_table" "default" {
    vpc_id = "${aws_vpc.default.id}"

    route {
        cidr_block = "0.0.0.0/0"
        gateway_id = "${aws_internet_gateway.default.id}"
    }
    lifecycle {
        ignore_changes = ["route"]
    }
}

If you comment the ignore_changes line it applies fine.

[carlsverre]

• Note: I originally had create_before_destroy specified as well, this was unneeded and doesn't affect the repo so I removed it for clarity.

[dverbeek84]

I have the same issue. Only on initial run and destroy.

[hanninen]

Same here, diff's didn't match during apply error is shown on each terraform apply, when ignore_changes is on for the aws_route_table resource.

[mgoodness]

This directive is a requirement for the way I'm provisioning a Kubernetes cluster with AWS cloud provider support. Kubernetes adjusts the route table at startup to suit its needs. Without ignore_changes, TF resets those changes.

[phinze]

Hi folks, some causes for diffs didn't apply on ignore_changes were fixed up in #4965. Others will be tackled in #5627 by me. Head to #5627 if you're still having issues on v0.6.12.

[carlsverre]

Awesome - thanks phinze! Since original report I ended up going a different direction that didn't require ignore_changes. Will loop back if I encounter any more issues with it.

[ghost]

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