fix: changes validation of empty provider credentials from Error to Warning

[AgustinBettati]

Description

Jira ticket: INTMDB-1127
GH issue: #1483

Type of change:

• Bug fix (non-breaking change which fixes an issue). Please, add the "bug" label to the PR.
• New feature (non-breaking change which adds functionality). Please, add the "enhancement" label to the PR.
• Breaking change (fix or feature that would cause existing functionality to not work as expected). Please, add the "breaking change" label to the PR.
• This change requires a documentation update
• Documentation fix/enhancement

Required Checklist:

• I have signed the MongoDB CLA
• I have read the contribution guidelines
• I have added tests that prove my fix is effective or that my feature works per HashiCorp requirements
• I have added any necessary documentation (if appropriate)
• I have run make fmt and formatted my code
• If changes include deprecations or removals, I defined an isolated PR with a relevant title as it will be used in the auto-generated changelog.

Further comments

Found limitations when trying to define an acceptance test to verify warning is correctly returned:

• terraform-plugin-testing currently does not support asserting warning results Ability to test whether warnings are raised during test steps hashicorp/terraform-plugin-testing#69

Manual testing verification

TF config with no environment variables defined:

provider "mongodbatlas" {
  base_url = "https://cloud-dev.mongodb.com/"
}

resource "mongodbatlas_project" "test" {
  name  			 = "some-name"
  org_id 			 = "<ORG-ID>"
}

terraform plan

Plan: 1 to add, 0 to change, 0 to destroy.
╷
│ Warning: either Atlas Programmatic API Keys or AWS Secrets Manager attributes must be set
│ 
│   with provider["registry.terraform.io/mongodb/mongodbatlas"],
│   on main.tf line 11, in provider "mongodbatlas":
│   11: provider "mongodbatlas" {
│ 
│ (and one more similar warning elsewhere)
╵
╷
│ Warning: error in configuring the provider.
│ 
│   with provider["registry.terraform.io/mongodb/mongodbatlas"],
│   on main.tf line 11, in provider "mongodbatlas":
│   11: provider "mongodbatlas" {
│ 
│ either Atlas Programmatic API Keys or AWS Secrets Manager attributes must be set

terraform apply

mongodbatlas_project.test: Creating...
╷
│ Warning: either Atlas Programmatic API Keys or AWS Secrets Manager attributes must be set
│ 
│   with provider["registry.terraform.io/mongodb/mongodbatlas"],
│   on main.tf line 11, in provider "mongodbatlas":
│   11: provider "mongodbatlas" {
│ 
│ (and one more similar warning elsewhere)
╵
╷
│ Warning: error in configuring the provider.
│ 
│   with provider["registry.terraform.io/mongodb/mongodbatlas"],
│   on main.tf line 11, in provider "mongodbatlas":
│   11: provider "mongodbatlas" {
│ 
│ either Atlas Programmatic API Keys or AWS Secrets Manager attributes must be set
╵
╷
│ Error: error creating Project: %s
│ 
│   with mongodbatlas_project.test,
│   on main.tf line 15, in resource "mongodbatlas_project" "test":
│   15: resource "mongodbatlas_project" "test" {
│ 
│ POST https://cloud-dev.mongodb.com/api/atlas/v1.0/groups: 401 (request "") You are not authorized for this resource.

[github-actions]

Package	Line Rate	Health
github.com/mongodb/terraform-provider-mongodbatlas/mongodbatlas	2%	❌
github.com/mongodb/terraform-provider-mongodbatlas/mongodbatlas/framework/validator	68%	➖
github.com/mongodb/terraform-provider-mongodbatlas/mongodbatlas/util	20%	❌
Summary	3% (279 / 10575)	❌

[andreaangiolillo]

LGTM