fix: improve error message for invalid provider credentials

[ddebko]

Summary:

When creating the boundary terraform provider:

provider "boundary" {
  addr                            = "http://127.0.0.1:9200"
  auth_method_id                  = "ampw_1234567890" 
  password_auth_method_login_name = "admin"          
  password_auth_method_password   = "password"       
}

When an error is returned from a failed authentication, we describe the raw api response. Example:

 Error: {"kind":"NotFound", "message":"Resource not found."}
│ 
│   with provider["registry.terraform.io/hashicorp/boundary"],
│   on main.tf line 10, in provider "boundary":
│   10: provider "boundary" {

This error is not really helpful and the true source of the issue is an invalid auth method id.

Solution

Perform an api error casting check from the authentication request. On a 401 return an error describing that the login name or password are invalid. On a 404 return an error describing that the auth method id is invalid. Otherwise just return the error from the response.

Examples:

Bad login name or password:

Error: invalid login name or password: {"kind":"Unauthenticated","message":"Unable to authenticate."}
│ 
│   with provider["localhost/providers/boundary"],
│   on main.tf line 10, in provider "boundary":
│   10: provider "boundary" {

Bad auth method id:

 Error: unknown auth_method_id: {"kind":"NotFound","message":"Resource not found."}
│ 
│   with provider["localhost/providers/boundary"],
│   on main.tf line 10, in provider "boundary":
│   10: provider "boundary" {

Bad url:

│ Error: error performing client request during Authenticate call: Post "http://127.0.0.1:9201/v1/auth-methods/ampw_1234567890:authenticate": EOF
│ 
│   with provider["localhost/providers/boundary"],
│   on main.tf line 10, in provider "boundary":
│   10: provider "boundary" {

[johanbrandhorst]

Great job!