Merge pull request LeanerCloud#79 from cristim/improve_replacement_logic

Improve replacement logic

core/autoscaling.go

@@ -516,7 +516,7 @@ func (a *autoScalingGroup) launchCheapestSpotInstance(azToLaunchIn *string) {
 	}
 
 	logger.Println("Trying to launch spot instance in", *azToLaunchIn,
-		"\nfirst finding an on-demand instance to use as a template")
+		"first finding an on-demand instance to use as a template")
 
 	baseInstance := a.findOndemandInstanceInAZ(azToLaunchIn)
 
@@ -528,7 +528,7 @@ func (a *autoScalingGroup) launchCheapestSpotInstance(azToLaunchIn *string) {
 
 	newInstanceType, err := baseInstance.getCheapestCompatibleSpotInstanceType()
 
-	if newInstanceType == nil {
+	if err != nil {
 		logger.Println("No cheaper compatible instance type was found, "+
 			"nothing to do here...", err)
 		return
@@ -537,20 +537,19 @@ func (a *autoScalingGroup) launchCheapestSpotInstance(azToLaunchIn *string) {
 	baseOnDemandPrice := baseInstance.price
 
 	currentSpotPrice := a.region.
-		instanceTypeInformation[*newInstanceType].pricing.spot[*azToLaunchIn]
+		instanceTypeInformation[newInstanceType].pricing.spot[*azToLaunchIn]
 
-	logger.Println("Finished searching for best spot instance in ",
-		*azToLaunchIn,
-		"\nreplacing an on-demand", *baseInstance.InstanceType,
-		"instance having the ondemand price", baseOnDemandPrice,
-		"\nLaunching best compatible instance:", *newInstanceType,
+	logger.Println("Finished searching for best spot instance in ", *azToLaunchIn)
+	logger.Println("Replacing an on-demand", *baseInstance.InstanceType,
+		"instance having the ondemand price", baseOnDemandPrice)
+	logger.Println("Launching best compatible instance:", newInstanceType,
 		"with current spot price:", currentSpotPrice)
 
 	lc := a.getLaunchConfiguration()
 
 	spotLS := lc.convertLaunchConfigurationToSpotSpecification(
 		baseInstance,
-		*newInstanceType,
+		newInstanceType,
 		*azToLaunchIn)
 
 	logger.Println("Bidding for spot instance for ", a.name)

core/autoscaling_test.go

@@ -6,7 +6,6 @@ import (
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/autoscaling"
 	"github.com/aws/aws-sdk-go/service/ec2"
-	"github.com/aws/aws-sdk-go/service/ec2/ec2iface"
 )
 
 func TestGetTagValue(t *testing.T) {
@@ -965,14 +964,6 @@ func TestAlreadyRunningInstanceCount(t *testing.T) {
 	}
 }
 
-type mockEC2Client struct {
-	ec2iface.EC2API
-}
-
-func (m *mockEC2Client) TerminateInstances(*ec2.TerminateInstancesInput) (*ec2.TerminateInstancesOutput, error) {
-	return nil, nil
-}
-
 func TestNeedReplaceOnDemandInstances(t *testing.T) {
 	tests := []struct {
 		name            string
@@ -1052,7 +1043,7 @@ func TestNeedReplaceOnDemandInstances(t *testing.T) {
 						region: &region{
 							name: "test-region",
 							services: connections{
-								ec2: &mockEC2Client{},
+								ec2: &mock{},
 							},
 						},
 					},