Remove Grafana provider for EKS (#179)

* Remove Grafana provider for EKS

* Drop provider

* Add provider constraint config

examples/existing-cluster-with-base-and-infra/README.md

@@ -21,7 +21,6 @@ View the full documentation for this example [here](https://aws-observability.gi
 |------|---------|
 | <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 1.1.0 |
 | <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 4.0.0 |
-| <a name="requirement_grafana"></a> [grafana](#requirement\_grafana) | >= 1.25.0 |
 | <a name="requirement_helm"></a> [helm](#requirement\_helm) | >= 2.4.1 |
 | <a name="requirement_kubectl"></a> [kubectl](#requirement\_kubectl) | >= 1.14 |
 | <a name="requirement_kubernetes"></a> [kubernetes](#requirement\_kubernetes) | >= 2.10 |

examples/existing-cluster-with-base-and-infra/main.tf

@@ -50,23 +50,11 @@ module "aws_observability_accelerator" {
   enable_alertmanager = true
 
   # reusing existing Amazon Managed Grafana workspace
-  # This is not needed anymore but kept here for a two step transition into
-  # removing the Terraform Grafana provider
   managed_grafana_workspace_id = var.managed_grafana_workspace_id
-  grafana_api_key              = var.grafana_api_key
 
   tags = local.tags
 }
 
-# https://www.terraform.io/language/modules/develop/providers
-# A module intended to be called by one or more other modules must not contain
-# any provider blocks.
-# This allows forcing dependency between base and workloads module
-provider "grafana" {
-  url  = module.aws_observability_accelerator.managed_grafana_workspace_endpoint
-  auth = var.grafana_api_key
-}
-
 module "eks_monitoring" {
   source = "../../modules/eks-monitoring"
   # source = "github.com/aws-observability/terraform-aws-observability-accelerator//modules/eks-monitoring?ref=v2.0.0"

examples/existing-cluster-with-base-and-infra/versions.tf

@@ -18,10 +18,6 @@ terraform {
       source  = "hashicorp/helm"
       version = ">= 2.4.1"
     }
-    grafana = {
-      source  = "grafana/grafana"
-      version = ">= 1.25.0"
-    }
   }
 
   # ##  Used for end-to-end testing on project; update to suit your needs