func destroyECSLaunchConfiguration()

in tools/workflow/clean_aws_resources.go [184:275]
53 lines of code
12 McCabe index (conditional complexity)

func destroyECSLaunchConfiguration() {
	//Set up aws go sdk ec2 client
	testSession, err := session.NewSession()

	if err != nil {
		log.Fatalf("Error creating session %v", err)
	}

	ec2client := ec2.New(testSession)
	autoscalingclient := autoscaling.New(testSession)

	//Allow to load all the launch configurations since the default respond is paginated launch configurations.
	//Look into the documentations and read the starting-token for more details
	//Documentation: https://docs.aws.amazon.com/cli/latest/reference/autoscaling/describe-launch-configurations.html#options
	var nextToken *string

	for {
		//Launch Configuration Go SDK currently does not support filter tag or filter wildcard. Only supports with matching name
		//Documentation: https://github.com/aws/aws-sdk-go/blob/02266ed24221ac21bb37d6ac614d1ced95407556/service/autoscaling/api.go#L9577-L9593
		describeLaunchConfigurationInputs := &autoscaling.DescribeLaunchConfigurationsInput{NextToken: nextToken}
		describeLaunchConfigurationOutputs, err := autoscalingclient.DescribeLaunchConfigurations(describeLaunchConfigurationInputs)

		if err != nil {
			log.Fatalf("Failed to get metadata from launch configuration because of %v", err)
		}

		for _, lc := range describeLaunchConfigurationOutputs.LaunchConfigurations {

			//Skipping lc that does not contain cluster-aoc-testing string (relating to aws-otel-test-framework)
			if filterLcNameResult := strings.Contains(*lc.LaunchConfigurationName, containLcName); !filterLcNameResult {
				continue
			}

			//Skipping lc that does not older than 5 days
			if !time.Now().UTC().Add(pastDayDeleteCalculation).After(*lc.CreatedTime) {
				continue
			}

			//Split the instance profile to get the testing ID associate with the testing framework
			splitLcIamInstanceProfile := strings.Split(*lc.IamInstanceProfile, "-")

			if len(splitLcIamInstanceProfile) != requiredIAMInstanceProfileLength {
				continue
			}

			//Check if the ec2 instance which is created by ecs is still exist with this launch configuration
			//In order to confirm if these load configurations are still being used

			var testingId string = splitLcIamInstanceProfile[5]
			var ec2InstanceName string = "cluster-worker-aoc-testing-" + testingId

			//State filter
			instanceStateFilter := ec2.Filter{Name: aws.String("instance-state-name"), Values: []*string{aws.String("running")}}
			//Tag filter
			instanceTagFilter := ec2.Filter{Name: aws.String("tag:Name"), Values: []*string{aws.String(ec2InstanceName)}}

			describeInstancesInput := ec2.DescribeInstancesInput{Filters: []*ec2.Filter{&instanceStateFilter, &instanceTagFilter}, NextToken: nextToken}
			describeInstancesOutput, err := ec2client.DescribeInstances(&describeInstancesInput)

			if err != nil {
				log.Fatalf("Failed to get metadata from EC2 instance because of %v", err)
			}

			//Confirm whether the ec2 associaed with the ecs is still exist or not
			if len(describeInstancesOutput.Reservations) != 0 {
				continue
			}

			log.Printf("Trying to delete lc %s with launch-date %v", *lc.LaunchConfigurationName, lc.CreatedTime)

			deleteLaunchConfigurationInput := &autoscaling.DeleteLaunchConfigurationInput{
				LaunchConfigurationName: lc.LaunchConfigurationName,
			}

			_, err = autoscalingclient.DeleteLaunchConfiguration(deleteLaunchConfigurationInput)

			if err != nil {
				log.Fatalf("Failed to delete lc %s because of %v", *lc.LaunchConfigurationName, err)
			}

			log.Printf("Delete lc %s successfully", *lc.LaunchConfigurationName)

		}

		if describeLaunchConfigurationOutputs.NextToken == nil {
			break
		}

		nextToken = describeLaunchConfigurationOutputs.NextToken
	}

}