Terraform crashed: interface {} is string, not float64

[yeighta]

Terraform Version

1.5.2

Terraform Configuration Files

...terraform config...

Debug Output

!!!!!!!!!!!!!!!!!!!!!!!!!!! TERRAFORM CRASH !!!!!!!!!!!!!!!!!!!!!!!!!!!!

Terraform crashed! This is always indicative of a bug within Terraform.
Please report the crash with Terraform[1] so that we can fix this.

When reporting bugs, please include your terraform version, the stack trace
shown below, and any additional information which may help replicate the issue.

[1]: https://github.com/hashicorp/terraform/issues

!!!!!!!!!!!!!!!!!!!!!!!!!!! TERRAFORM CRASH !!!!!!!!!!!!!!!!!!!!!!!!!!!!


Apply complete! Resources: 0 added, 0 changed, 0 destroyed.
interface conversion: interface {} is string, not float64
goroutine 37 [running]:
runtime/debug.Stack()
        /Users/runner/hostedtoolcache/go/1.20.0/x64/src/runtime/debug/stack.go:24 +0x65
runtime/debug.PrintStack()
        /Users/runner/hostedtoolcache/go/1.20.0/x64/src/runtime/debug/stack.go:16 +0x19
github.com/hashicorp/terraform/internal/logging.PanicHandler()
        /Users/runner/work/terraform/terraform/internal/logging/panic.go:58 +0x153
panic({0x304bf80, 0xc002452d80})
        /Users/runner/hostedtoolcache/go/1.20.0/x64/src/runtime/panic.go:884 +0x213
github.com/hashicorp/terraform/internal/command/jsonformat/structured/attribute_path.(*PathMatcher).GetChildWithIndex(0xc00013be60, 0x0)
        /Users/runner/work/terraform/terraform/internal/command/jsonformat/structured/attribute_path/matcher.go:176 +0x2cb
github.com/hashicorp/terraform/internal/command/jsonformat/structured.ChangeSlice.GetChild({{0xc002bd69e0, 0x1, 0x1}, {0xc002bd6da0, 0x1, 0x1}, {0x0, 0x0, 0x0}, {0xc002bd6f30, ...}, ...}, ...)
        /Users/runner/work/terraform/terraform/internal/command/jsonformat/structured/slice.go:75 +0x252
github.com/hashicorp/terraform/internal/command/jsonformat/differ.processNestedList({0x1, 0x1, {0x2ed0720, 0xc0019cb980}, {0x2ed0720, 0xc0019cbb60}, {0x0, 0x0}, {0x2ed0720, 0xc0019cbd58}, ...}, ...)
        /Users/runner/work/terraform/terraform/internal/command/jsonformat/differ/list.go:83 +0x13b
github.com/hashicorp/terraform/internal/command/jsonformat/differ.computeBlockDiffsAsList({0x1, 0x1, {0x2ed0720, 0xc0019cb980}, {0x2ed0720, 0xc0019cbb60}, {0x0, 0x0}, {0x2ed0720, 0xc0019cbd58}, ...}, ...)
        /Users/runner/work/terraform/terraform/internal/command/jsonformat/differ/list.go:72 +0x145
github.com/hashicorp/terraform/internal/command/jsonformat/differ.ComputeDiffForBlock({0x0, 0x0, {0x3007cc0, 0xc0022e2c90}, {0x3007cc0, 0xc0022e2f00}, {0x3007cc0, 0xc0022e3140}, {0x3007cc0, 0xc0022e3170}, ...}, ...)
        /Users/runner/work/terraform/terraform/internal/command/jsonformat/differ/block.go:92 +0xf98
github.com/hashicorp/terraform/internal/command/jsonformat.precomputeDiffs({{0x33dc6ed, 0x3}, 0xc001bf5fb0, {0xc0006cf000, 0x13, 0x22}, {0xc0012fc800, 0xa, 0x11}, {0xc0019fd680, ...}, ...}, ...)
        /Users/runner/work/terraform/terraform/internal/command/jsonformat/diff.go:52 +0x3b8
github.com/hashicorp/terraform/internal/command/jsonformat.Plan.renderHuman({{0x33dc6ed, 0x3}, 0xc001bf5fb0, {0xc0006cf000, 0x13, 0x22}, {0xc0012fc800, 0xa, 0x11}, {0xc0019fd680, ...}, ...}, ...)
        /Users/runner/work/terraform/terraform/internal/command/jsonformat/plan.go:64 +0xa5
github.com/hashicorp/terraform/internal/command/jsonformat.Renderer.RenderHumanPlan({0xc000120d68?, 0xc0002a6cc0?, 0x17?}, {{0x33dc6ed, 0x3}, 0xc001bf5fb0, {0xc0006cf000, 0x13, 0x22}, {0xc0012fc800, ...}, ...}, ...)
        /Users/runner/work/terraform/terraform/internal/command/jsonformat/renderer.go:92 +0x1ef
github.com/hashicorp/terraform/internal/command/views.(*OperationHuman).Plan(0xc000ac0790, 0xc0010983c0, 0x0?)
        /Users/runner/work/terraform/terraform/internal/command/views/operation.go:126 +0x31c
github.com/hashicorp/terraform/internal/backend/local.(*Local).opApply(0x0?, {0x39deb38, 0xc0008343c0}, {0x39deb38, 0xc000834410}, 0xc000aba5a0, 0xc000aaed00)
        /Users/runner/work/terraform/terraform/internal/backend/local/backend_apply.go:117 +0x996
github.com/hashicorp/terraform/internal/backend/local.(*Local).Operation.func1()
        /Users/runner/work/terraform/terraform/internal/backend/local/backend.go:326 +0xc3
created by github.com/hashicorp/terraform/internal/backend/local.(*Local).Operation
        /Users/runner/work/terraform/terraform/internal/backend/local/backend.go:319 +0x44a
make: *** [apply] Error 11

Expected Behavior

I expected terraform apply successfully

Actual Behavior

terraform crashed

Steps to Reproduce

1. terraform init
2. terraform apply

Additional Context

No response

References

No response

[liamcervante]

Hi @baeyear, thanks for filing this!

Are you able to share your configuration, so I can debug and reproduce locally?

Alternatively, if you run the following:

• terraform plan -out planfile
• terraform show -json planfile

That should print out a JSONified version of the plan, which I can also use to reproduce locally.

Thanks!

[yeighta]

Hi, @liamcervante .

Hello, thank you for your response.

I apologize, but I am unable to execute the above command since I have closed the billing account and destroyed the project on GCP.

Instead, I will detail the part of the code where the issue was reproduced.

I encountered a terraform crash when I specified the google_datastream_connection_profile.postgresql_profile.hostname as follows:

resource "google_datastream_connection_profile" "alloydb" {
  display_name          = "AlloyDB Connection profile"
  location              = var.default_region
  connection_profile_id = "alloydb-connection-profile"
  project               = var.project_id

  postgresql_profile {
    hostname = google_compute_instance.main.network_interface["0"].network_ip
    port     = "5432"
    username = sensitive(var.alloydb_datastream.username)
    password = sensitive(var.alloydb_datastream.password)
    database = "postgres"
  }

  private_connectivity {
    private_connection = google_datastream_private_connection.main.id
  }
}

However, when I changed the syntax to the following, the crash did not occur.

resource "google_datastream_connection_profile" "alloydb" {
  display_name          = "AlloyDB Connection profile"
  location              = var.default_region
  connection_profile_id = "alloydb-connection-profile"
  project               = var.project_id

  postgresql_profile {
    hostname = google_compute_instance.main.network_interface.0.network_ip
    port     = "5432"
    username = sensitive(var.alloydb_datastream.username)
    password = sensitive(var.alloydb_datastream.password)
    database = "postgres"
  }

  private_connectivity {
    private_connection = google_datastream_private_connection.main.id
  }
}

I hope this information is useful. Thank you for your understanding.

[liamcervante]

Thanks for that, it's very helpful.

So I think the crash is being caused by this line: google_compute_instance.main.network_interface["0"].network_ip

The renderer is expecting that 0 to be an int not a string, as you spotted in your updated config. But Terraform definitely shouldn't crash in this case, so I will put together a fix so it interprets the string as a number where possible and handles the error properly otherwise.

Thnaks!