Terraform 0.13.5 crash when creating GCS bucket

[ghost]

This issue was originally opened by @syedrakib as hashicorp/terraform#26771. It was migrated here as a result of the provider split. The original body of the issue is below.

---

Terraform Version

Terraform v0.13.5
+ provider registry.terraform.io/hashicorp/google v3.45.0
+ provider registry.terraform.io/hashicorp/google-beta v3.45.0
+ provider registry.terraform.io/hashicorp/null v3.0.0
+ provider registry.terraform.io/hashicorp/random v2.3.0

Terraform Plan

All other resources and modules have been created and refreshing successfully. Only this 1 resource is left to create:

  # module.prd_infra.module.gcs_bucket.google_storage_bucket.gcs_bucket will be created
  + resource "google_storage_bucket" "gcs_bucket" {
      + bucket_policy_only          = (known after apply)
      + force_destroy               = false
      + id                          = (known after apply)
      + labels                      = {}
      + location                    = "ASIA-SOUTHEAST1"
      + name                        = "my-bucket-tfprd-unicorn"
      + project                     = (known after apply)
      + self_link                   = (known after apply)
      + storage_class               = "STANDARD"
      + uniform_bucket_level_access = false
      + url                         = (known after apply)
      + cors {}
      + versioning {
          + enabled = false
        }
      + website {
          + main_page_suffix = "index.html"
          + not_found_page   = "404.html"
        }
    }

Crash Output

https://gist.github.com/syedrakib/0e0338ac106f37ca4ec3849a0d0eb431

Expected Behavior

The GCS bucket should just create. Or should fail with a proper error message.

Actual Behavior

Crashing with this crash.log

Additional Context

The crash log and error message are unclear

[syedrakib]

Ok. After troubleshooting the GCS module that i used, turns out the cors {} line in it was the bad player. Removing that line helped. The bucket created successfully.

However, TF should produce a more reasonable error message than the crash.log that it produced. Is it something that can be addressed?

[venkykuberan]

Added the fix for crash/panic situation, however its advised not to use the empty (cors) block in the config, as API may not return any data for that object in the response. In that case TF stores nothing on your state file for the cors and the subsequent plan finds difference (perma diff) between your config & state.
I would recommend either use the cors block with attributes or don't use it, as its an optional.

[syedrakib]

Hey @venkykuberan . Yes you are right. It was certainly a bug from our side. We shouldn't have added empty cors block to begin with.

However, the error experience made it difficult for us to find out our mistake. Thanks for arranging the fix :)

[syedrakib]

BTW, is there any PR or merge that you can refer to for this fix?

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. If you feel I made an error 🤖 🙉 , please reach out to my human friends 👉 hashibot-feedback@hashicorp.com. Thanks!