Implement better error message when the AWS region or AWS default reg…

…ion is missing (closes #506) (#507)

v2/internal/providers/aws.go

@@ -10,6 +10,7 @@ import (
 	smithyhttp "github.com/aws/smithy-go/transport/http"
 	"github.com/google/uuid"
 	"log"
+	"os"
 )
 
 type AWSProvider struct {
@@ -34,7 +35,17 @@ func (m *AWSProvider) IsAuthenticatedAgainstAWS() bool {
 	// instead of sts:GetCallerIdentity, to ensure an AWS region was properly set
 	ec2Client := ec2.NewFromConfig(m.GetConnection())
 	_, err := ec2Client.DescribeAccountAttributes(context.Background(), &ec2.DescribeAccountAttributesInput{})
-	return err == nil
+	if err != nil {
+		return false
+	}
+
+	// Note: Explicitly setting AWS_REGION/AWS_DEFAULT_REGION is not strictly required for the AWS SDK to work, but it is necessary for Terraform
+	// If it's not set, we get a user-unfriendly error such as the one describe at https://github.com/DataDog/stratus-red-team/issues/506
+	if os.Getenv("AWS_REGION") == "" && os.Getenv("AWS_DEFAULT_REGION") == "" {
+		return false
+	}
+
+	return true
 }
 
 // Functions below are related to customization of the user-agent header

v2/pkg/stratus/providers.go

@@ -57,9 +57,10 @@ func EnsureAuthenticated(platform Platform) error {
 	switch platform {
 	case AWS:
 		if !providerFactory.AWS().IsAuthenticatedAgainstAWS() {
-			return errors.New("you are not authenticated against AWS, or you have not set your region. " +
-				"Make sure you are authenticated against AWS, and you have a default region set in your AWS config " +
-				"or environment (export AWS_DEFAULT_REGION=us-east-1)")
+			return errors.New("you are not authenticated against AWS, *or* you have not set your region. \n\n" +
+				"Troubleshooting:\n" +
+				"1. Are you authenticated against AWS?\n" +
+				"2. Do you have a region or default region set (whether in your AWS configuration file or in your environment)? If not, run 'export AWS_REGION=xxx'")
 		}
 	case Azure:
 		if !providerFactory.Azure().IsAuthenticatedAgainstAzure() {