removing liveness_probe declaration from google_cloud_run_v2_service does not remove the probe from the service

[breathe]

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Terraform Version

• Latest terraform as installed by hashicorp/setup-terraform@v3 github action
• using hashicorp/google v5.18.0

Affected Resource(s)

google_cloud_run_v2_service

Terraform Configuration

resource "google_cloud_run_v2_service" "service" {
  name     = local.SERVICE
  location = var.GOOGLE_CLOUD_REGION

  template {

    max_instance_request_concurrency = 250

    scaling {
      max_instance_count = 1
    }
    containers {

      resources {
        cpu_idle = false
      }

      image = var.IMAGE

      startup_probe {
        failure_threshold     = 3
        initial_delay_seconds = 10
        timeout_seconds       = 5
        period_seconds        = 5

        tcp_socket {
          port = 8080
        }
      }

      # NOTE: due to a terraform bug, removing the liveness_probe configuration doesn't actually unconfigure the liveness probe ...
      # liveness_probe {
      #   failure_threshold = 7
      #   timeout_seconds   = 10
      #   period_seconds    = 10

      #   http_get {
      #     path = "/"
      #   }
      # }
}

Debug Output

No response

Expected Behavior

No response

Actual Behavior

No response

Steps to reproduce

1. Create a cloud run v2 service with a liveness_probe declaration: terraform apply
2. Modify configuration to remove the liveness_probe config
3. re-run terraform plan/apply and you'll notice that it doesn't actually remove the liveness_probe related configuration from the newly deployed cloud_run revision

Important Factoids

No response

References

No response

b/328077381

[rileykarson]

This field was marked as Optional+Computed (default_from_api in our code generator) which preserves the existing value when a field is removed from config (specifically is null, but that's how most users will null a field). If it were just Optional, nulling the field would indicate removal rather than preservation.

This means the behaviour is correct as written, but could very well be wrong- it was marked as such in GoogleCloudPlatform/magic-modules#6987. That's an unusual change, and I can't tell if it was intended or not, as it doesn't seem to have been discussed in review.

If there's any situation that Cloud Run will provide a liveness_probe value when one wasn't sent, marking it this way was correct and the surprise behaviour you're seeing is a side effect. However if it isn't, we should remove Computed: true in a major release so that removing the block no longer preserves the value.

[breathe]

If there's any situation that Cloud Run will provide a liveness_probe value when one wasn't sent, marking it this way was correct and the surprise behaviour you're seeing is a side effect. However if it isn't, we should remove Computed: true in a major release so that removing the block no longer preserves the value.

I believe that cloud_run does provide a default value when one is not supplied for the startup_probe (there must be a startup_probe defined).

I'm not completely sure what the behavior is with respect to liveness_probe -- if there is one enabled by default its operation doesn't produce any visible gcloud logs -- and while google explicitly documents the default behavior of the startup_probe I don't find similar language anywhere for the liveness_probe ...

When I remove the liveness_probe configuration parameter via the ui -- nothing about it is visible in the ui any longer ...

[AndreaGiardini]

@breathe @rileykarson I think this issue can be closed?

Could you please double-check if #20753 is the same problem on a different field? Happy to open a PR if that's the case