fix: load the file content instead of base64 encoded payload for uploading the zipfile in resource_alicloud_fc_layer_version.go

[NIZ-elsevier]

What's the problem?

With the current version, a FC layer can be created with a local zipfile, but the plugin is unable to do any follow-up terraform plan or terraform apply. In my testing ,my custom layer was only 1.2 MB, but still exceeding the grpc maximum input limit. I think it's because the provider plugin is trying to compare the encoded base64 contents. For a zipfile, it's payload can be incredibly large...

Error message:

Planning failed. Terraform encountered an error while generating this plan.

╷
│ Error: Plugin error
│
│   with module.ami-manager.alicloud_fc_layer_version.ecs_layer,
│   on ../../../core-alicloud-ami-manager/function.tf line 25, in resource "alicloud_fc_layer_version" "ecs_layer":
│   25: resource "alicloud_fc_layer_version" "ecs_layer" {
│
│ The plugin returned an unexpected error from plugin.(*GRPCProvider).PlanResourceChange: rpc error: code = ResourceExhausted desc = grpc: received message
│ larger than max (4706981 vs. 4194304)

How to reproduce the problem?

Create a resource as follows:

resource "alicloud_fc_layer_version" "ecs_layer" {
  layer_name         = "ecs_layer"
  description        = "A layer for python module alibabacloud_ecs20140526"
  compatible_runtime = ["python3.10"]
  zip_file           = filebase64("${path.module}/function_compute/alibabacloud_ecs20140526.zip")
}

My changes

As following the code block in the resource_alicloud_fc_function.go, I think it would be wise to use the same approach to load the content, rather than loading the raw payload of a zipfile. ref: https://github.com/aliyun/terraform-provider-alicloud/blob/master/alicloud/resource_alicloud_fc_function.go#L448-L453

Please verify my changes, or let me know how shall I test them properly. I can submit another change regarding the similar code block in resource resource_alicloud_fcv3_layer_version.go too if this is deemed good enough. Thanks.