Merge branch 'emilyring-master-patch-66980' into 'master'

Documented EKS form changes

See merge request gitlab-org/gitlab!45907

doc/user/project/clusters/add_eks_clusters.md

@@ -139,6 +139,7 @@ To create and add a new Kubernetes cluster to your project, group, or instance:
    1. Enter a role name and optional description into the fields provided.
    1. Click **Create role**, the new role name will appear at the top. Click on its name and copy the `Role ARN` from the newly created role.
 1. In GitLab, enter the copied role ARN into the `Role ARN` field.
+1. In the **Cluster Region** field, enter the [region](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html) you plan to use for your new cluster. GitLab will authenticate you have access to this region when authenticating your role. 
 1. Click **Authenticate with AWS**.
 1. Choose your cluster's settings:
    - **Kubernetes cluster name** - The name you wish to give the cluster.
@@ -152,9 +153,6 @@ To create and add a new Kubernetes cluster to your project, group, or instance:
      the one you created much earlier by following the
      [Amazon EKS cluster IAM role](https://docs.aws.amazon.com/eks/latest/userguide/service_IAM_role.html)
      guide.
-
-   - **Region** - The [region](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html)
-     in which the cluster will be created.
    - **Key pair name** - Select the [key pair](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html)
      that you can use to connect to your worker nodes if required.
    - **VPC** - Select a [VPC](https://docs.aws.amazon.com/vpc/latest/userguide/what-is-amazon-vpc.html)
@@ -184,9 +182,10 @@ The following errors are commonly encountered when creating a new cluster.
 #### Error: Request failed with status code 422
 
 When submitting the initial authentication form, GitLab returns a status code 422
-error when it can't determine the role you've provided. Make sure you've
+error when it can't determine the role or region you've provided. Make sure you've
 correctly configured your role with the **Account ID** and **External ID**
-provided by GitLab. In GitLab, make sure to enter the correct **Role ARN**.
+provided by GitLab. In GitLab, make sure to enter the correct **Role ARN**. 
+Make sure you also have access to the chosen region.
 
 #### Could not load Security Groups for this VPC