Merge pull request #262 from vmercierfr/hotfix-x2g

Fix for x2g RDS instance family

Author: vmercierfr

internal/app/ec2/ec2.go

@@ -75,7 +75,7 @@ func (e *EC2Fetcher) GetDBInstanceTypeInformation(instanceTypes []string) (Metri
 		// Remove "db." prefix from instance types
 		instanceTypesToFetch := make([]aws_ec2_types.InstanceType, len(instances))
 		for i, instance := range instances {
-			instanceTypesToFetch[i] = (aws_ec2_types.InstanceType)(removeDBPrefix(instance))
+			instanceTypesToFetch[i] = (aws_ec2_types.InstanceType)(overrideInvalidInstanceTypes(removeDBPrefix(instance)))
 		}
 
 		input := &aws_ec2.DescribeInstanceTypesInput{InstanceTypes: instanceTypesToFetch}

internal/app/ec2/helper.go

@@ -19,3 +19,15 @@ func addDBPrefix(instance string) string {
 func removeDBPrefix(instance string) string {
 	return strings.Trim(instance, "db.")
 }
+
+// overrideInvalidInstanceTypes normalizes EC2 instance type names to handle
+// inconsistencies between RDS and EC2 services.
+// x2g RDS instances which are memory-optimized instance classes with AWS Graviton2 processors
+// are referenced as x2gd in EC2 API
+// See: https://github.com/qonto/prometheus-rds-exporter/issues/258
+func overrideInvalidInstanceTypes(instanceType string) string {
+	if strings.HasPrefix(instanceType, "x2g.") {
+		return strings.Replace(instanceType, "x2g.", "x2gd.", 1)
+	}
+	return instanceType
+}