scaler(aws_ec2_asg): limit desired capacity between Max and Min size (#…

…27)

* Update aws_ec2_asg.go

* cap desiredCount between Max Min size

* use simple if case

internal/scaler/awsec2asg/aws_ec2_asg.go

@@ -318,25 +318,36 @@ func (s *Scaler) Register(ctx context.Context) error {
 			asg := asgOutput.AutoScalingGroups[0]
 
 			var updateAsg *autoscaling.UpdateAutoScalingGroupInput
+
+			desiredCapacity := inputData.DesiredCount
+
 			if *asg.DesiredCapacity < inputData.DesiredCount {
 				// scale-out
 				if s.DisableScaleOut != nil && *s.DisableScaleOut {
 					return
 				}
 
+				if desiredCapacity > *asg.MaxSize {
+					desiredCapacity = *asg.MaxSize
+				}
+
 				updateAsg = &autoscaling.UpdateAutoScalingGroupInput{
 					AutoScalingGroupName: &inputData.ASGName,
-					DesiredCapacity:      &inputData.DesiredCount,
+					DesiredCapacity:      &desiredCapacity,
 				}
 			} else if *asg.DesiredCapacity > inputData.DesiredCount {
 				// scale-in
 				if s.DisableScaleIn != nil && *s.DisableScaleIn {
 					return
 				}
 
+				if desiredCapacity < *asg.MinSize {
+					desiredCapacity = *asg.MinSize
+				}
+
 				updateAsg = &autoscaling.UpdateAutoScalingGroupInput{
 					AutoScalingGroupName: &inputData.ASGName,
-					DesiredCapacity:      &inputData.DesiredCount,
+					DesiredCapacity:      &desiredCapacity,
 				}
 			}