Change detected on any plan when we have PLATFORM_DEFAULT value for cloud_dns in google_container_cluster

[clementhemidy]

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Terraform Version & Provider Version(s)

Terraform v1.9.8
on darwin_amd64

• provider registry.terraform.io/hashicorp/google v6.26.0

Affected Resource(s)

• google_container_cluster

Terraform Configuration

No response

Debug Output

No response

Expected Behavior

There should be no difference in the plans if the value of cloud_dns is set to PLATFORM_DEFAULT and the cluster is already on the default value.

Actual Behavior

If the dns_config block is added with PLATFORM_DEFAULT as the value for cloud_dns, the provider detects a difference in every plan.

Steps to reproduce

1. create a cluster without dns_config
2. add a dns_config with PLATFORM_DEFAULT as dns_config.cluster_dns value

Important Factoids

No response

References

No response

[ggtisc]

Hi @clementhemidy

This time this is considered a normal behavior since you are working with terraform and it works internally with all changes in the tfstate file then if you are adding a new code block to your resources even if there are no chenges in cloud, terraform consider this as changes because they are impacting on the tfstate file

[clementhemidy]

@ggtisc Yes, but it’s not normal if an initial apply was done and on the next apply, the modification still appears to be applied (and this goes on infinitely).

[ggtisc]

after many executions of terraform apply command i can't get a permadiff issue. Could you please try basic troubleshooting like restarting your environment, re-authenticate, etc and make a new try?

[stevenbales]

We are seeing a similar issue in our clusters.

When passing in the default explicitly, eg:

dns_config {
    cluster_dns = "PROVIDER_UNSPECIFIED"
}

or when passing in nothing, eg:

dns_config {}

We get a permadiff.

When we pass in this, however:

dns_config {
    cluster_dns = "PLATFORM_DEFAULT"
}

We don't get any drift.

Another bug was fixed in 6.25.0 and is very similar, but affected cluster_dns_scope instead

[ggtisc]

Hi @stevenbales

Could you please share with us your full code to see what is happening? because at the moment it is not possible to get a permadiff