adding orphan instance files

orphan-instance/main.go

@@ -0,0 +1,158 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"strconv"
+	"time"
+
+	"github.com/aws/aws-lambda-go/lambda"
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/ec2"
+	"github.com/aws/aws-sdk-go/service/ssm"
+	log "github.com/cihub/seelog"
+)
+
+type MyEvent struct {
+	Version string `json:"version"`
+	Id      string `json:"id"`
+	Detail  Detail `json:"detail"`
+}
+
+type Detail struct {
+	InstanceId string `json:"EC2InstanceId"`
+	StatusCode string `json:"StatusCode"`
+}
+
+// type Detail struct {
+// 	InstanceId string `json:"instance-id"`
+// }
+
+func HandleRequest(ctx context.Context, event *MyEvent) (*string, error) {
+	var exitCode int64
+	if event == nil {
+		return nil, fmt.Errorf("received nil event")
+	}
+	data, err := json.Marshal(event)
+	if err != nil {
+		return nil, err
+	}
+	log.Infof("Event received: %s", string(data))
+
+	documentName := "test-orphan-stack-ECSOrphanInstanceSSMDocument-OLO04TqElqbe"
+
+	session, err := session.NewSession()
+	if err != nil {
+		return nil, err
+	}
+
+	svc := ec2.New(session)
+
+	// Waiting for instance to be in running state
+	for {
+		time.Sleep(1 * time.Second)
+		describeInput := &ec2.DescribeInstanceStatusInput{
+			InstanceIds: aws.StringSlice([]string{event.Detail.InstanceId}),
+		}
+		describeOutput, err := svc.DescribeInstanceStatus(describeInput)
+		if err != nil {
+			return nil, err
+		}
+		// Breaking out of the loop since the instance has reached running state
+		if *describeOutput.InstanceStatuses[0].InstanceState.Name == "running" {
+			log.Infof("Instance %s has reached running state", event.Detail.InstanceId)
+			break
+		}
+	}
+
+	ssmClient := ssm.New(session)
+	ssmInput := &ssm.SendCommandInput{
+		DocumentName:    aws.String(documentName),
+		DocumentVersion: aws.String("$LATEST"),
+		CloudWatchOutputConfig: &ssm.CloudWatchOutputConfig{
+			CloudWatchOutputEnabled: aws.Bool(true),
+			CloudWatchLogGroupName:  aws.String("orphan-instance-log-group"),
+		},
+		Targets: []*ssm.Target{
+			{
+				Key:    aws.String("InstanceIds"),
+				Values: aws.StringSlice([]string{event.Detail.InstanceId}),
+			},
+		},
+	}
+
+	// Sleeping to give ECS time to start up and attempt to register
+	sleepTime, err := strconv.Atoi(os.Getenv("WAIT_TIME"))
+	if err != nil {
+		return nil, err
+	}
+	log.Infof("Sleeping for %d seconds to give ECS time to start up.", sleepTime)
+	time.Sleep(time.Duration(sleepTime) * time.Second)
+
+	// Invoking SSM RunCommand
+	ssmOutput, err := ssmClient.SendCommand(ssmInput)
+	if err != nil {
+		return nil, err
+	}
+	commandId := *ssmOutput.Command.CommandId
+	message := fmt.Sprintf("Executed SSM document wtih command ID: %s", commandId)
+	log.Infof("Command ID: %s", commandId)
+
+	for {
+		time.Sleep(1 * time.Second)
+		getCommandInput := &ssm.GetCommandInvocationInput{
+			CommandId:  ssmOutput.Command.CommandId,
+			InstanceId: aws.String(event.Detail.InstanceId),
+		}
+
+		getCommandOutput, err := ssmClient.GetCommandInvocation(getCommandInput)
+		if err != nil {
+			continue
+		}
+
+		if *getCommandOutput.Status != "InProgress" {
+			exitCode = *getCommandOutput.ResponseCode
+			break
+		}
+	}
+	log.Info("SSM script has finished executing.")
+
+	shouldTerminate := os.Getenv("TERMINATE_INSTANCE")
+	if exitCode == 8 && shouldTerminate == "true" {
+		log.Infof("RegisterContainerInstance failure detected. Terminating instance...")
+
+		ec2Input := &ec2.TerminateInstancesInput{
+			InstanceIds: []*string{
+				aws.String(event.Detail.InstanceId),
+			},
+		}
+		_, err := svc.TerminateInstances(ec2Input)
+		if err != nil {
+			return nil, err
+		}
+
+		for {
+			time.Sleep(1 * time.Second)
+			describeInput := &ec2.DescribeInstanceStatusInput{
+				InstanceIds: aws.StringSlice([]string{event.Detail.InstanceId}),
+			}
+			describeOutput, err := svc.DescribeInstanceStatus(describeInput)
+			if err != nil {
+				return nil, err
+			}
+			// Breaking out of the loop since the instance has successfully terminated
+			if len(describeOutput.InstanceStatuses) == 0 || *describeOutput.InstanceStatuses[0].InstanceState.Name == "terminated" {
+				break
+			}
+		}
+		log.Infof("Instance with ID: %s, has successfully been terminated", event.Detail.InstanceId)
+	}
+	return &message, nil
+}
+
+func main() {
+	lambda.Start(HandleRequest)
+}