Not all messages are in JSON format when running `terraform init -json`

[SarahFrench]

Terraform Version

Terraform 1.15.0-dev

Terraform Configuration Files

terraform {
  required_providers {
    aws = {
      source = "hashicorp/aws"
    }
  }
  backend "local" {}
}

Debug Output

N/A

Expected Behavior

When running terraform init -json using the config above in an empty working directory, all of the command's output should be in JSON format.

Actual Behavior

One of the messages logged to the terminal isn't in JSON format:

{"@level":"info","@message":"Terraform 1.15.0-dev","@module":"terraform.ui","@timestamp":"2025-11-17T17:17:58.540604Z","terraform":"1.15.0-dev","type":"version","ui":"1.2"}
{"@level":"info","@message":"Initializing provider plugins found in the configuration...","@module":"terraform.ui","@timestamp":"2025-11-17T17:18:04.314Z","message_code":"initializing_provider_plugin_from_config_message","type":"init_output"}
{"@level":"info","@message":"hashicorp/aws: Finding latest version...","@module":"terraform.ui","@timestamp":"2025-11-17T17:18:04.314594Z","type":"log"}
{"@level":"info","@message":"Installing provider version: hashicorp/aws v6.21.0...","@module":"terraform.ui","@timestamp":"2025-11-17T17:18:04.784659Z","type":"log"}
{"@level":"info","@message":"Installed provider version: hashicorp/aws v6.21.0 (signed by HashiCorp)","@module":"terraform.ui","@timestamp":"2025-11-17T17:18:26.345919Z","type":"log"}
{"@level":"info","@message":"Initializing the backend...","@module":"terraform.ui","@timestamp":"2025-11-17T17:18:52.256Z","message_code":"initializing_backend_message","type":"init_output"}

Successfully configured the backend "local"! Terraform will automatically
use this backend unless the backend configuration changes.
{"@level":"info","@message":"Terraform has created a lock file .terraform.lock.hcl to record the provider\nselections it made above. Include this file in your version control repository\nso that Terraform can guarantee to make the same selections by default when\nyou run \"terraform init\" in the future.","@module":"terraform.ui","@timestamp":"2025-11-17T17:19:06.698Z","message_code":"lock_info","type":"init_output"}
{"@level":"info","@message":"Terraform has been successfully initialized!","@module":"terraform.ui","@timestamp":"2025-11-17T17:19:09.915Z","message_code":"output_init_success_message","type":"init_output"}
{"@level":"info","@message":"You may now begin working with Terraform. Try running \"terraform plan\" to see\nany changes that are required for your infrastructure. All Terraform commands\nshould now work.\n\nIf you ever set or change modules or backend configuration for Terraform,\nrerun this command to reinitialize your working directory. If you forget, other\ncommands will detect it and remind you to do so if necessary.","@module":"terraform.ui","@timestamp":"2025-11-17T17:19:10.553Z","message_code":"output_init_success_cli_message","type":"init_output"}

Successfully configured the backend "local"! Terraform will automatically
use this backend unless the backend configuration changes.

Steps to Reproduce

1. terraform init -json

Additional Context

The non-JSON message originates from:

terraform/internal/command/meta_backend.go

Lines 1355 to 1357 in 1dd8e60

	m.Ui.Output(m.Colorize().Color(fmt.Sprintf(
	"[reset][green]\n"+strings.TrimSpace(successBackendSet), s.Backend.Type)))
	}

I think that all parts of init-related code that use the Ui abstraction are unable to output logs in JSON format, as the View abstraction is needed for that.

This means running init in other situations (e.g. migrating when unsetting backend from the config) would have the same issue with JSON output.

References

See also:

• Migrate Terraform commands from cli.Ui to views.View abstractions when rendering output #37439

Generative AI / LLM assisted development?

N/A