Add nil pointer checks to avoid exception for VPC nuke

aws/resources/ec2.go

@@ -14,8 +14,35 @@ import (
 // returns only instance Ids of unprotected ec2 instances
 func (ei *EC2Instances) filterOutProtectedInstances(output *ec2.DescribeInstancesOutput, configObj config.Config) ([]*string, error) {
 	var filteredIds []*string
+	if output == nil {
+		logging.Debugf("DescribeInstancesOutput is nil")
+		return filteredIds, nil
+	}
+
+	if output.Reservations == nil {
+		logging.Debugf("No reservations found in DescribeInstancesOutput")
+		return filteredIds, nil
+	}
+
 	for _, reservation := range output.Reservations {
+		if reservation == nil {
+			logging.Debugf("Encountered a nil reservation")
+			continue
+		}
+		if reservation.Instances == nil {
+			logging.Debugf("No instances found in reservation")
+			continue
+		}
+
 		for _, instance := range reservation.Instances {
+			if instance == nil {
+				logging.Debugf("Encountered a nil instance in reservation")
+				continue
+			}
+			if instance.InstanceId == nil {
+				logging.Debugf("InstanceId is nil for an instance")
+				continue
+			}
 			instanceID := *instance.InstanceId
 
 			attr, err := ei.Client.DescribeInstanceAttributeWithContext(ei.Context, &ec2.DescribeInstanceAttributeInput{
@@ -26,6 +53,11 @@ func (ei *EC2Instances) filterOutProtectedInstances(output *ec2.DescribeInstance
 				return nil, errors.WithStackTrace(err)
 			}
 
+			if attr == nil || attr.DisableApiTermination == nil || attr.DisableApiTermination.Value == nil {
+				logging.Debugf("Missing or nil disableApiTermination attribute for instance: %s", instanceID)
+				continue
+			}
+
 			if shouldIncludeInstanceId(instance, *attr.DisableApiTermination.Value, configObj) {
 				filteredIds = append(filteredIds, &instanceID)
 			}
@@ -63,13 +95,25 @@ func (ei *EC2Instances) getAll(c context.Context, configObj config.Config) ([]*s
 }
 
 func shouldIncludeInstanceId(instance *ec2.Instance, protected bool, configObj config.Config) bool {
+	if instance == nil {
+		logging.Debugf("Encountered a nil instance")
+		return false
+	}
 	if protected {
+		logging.Debugf("Instance is protected: %s", awsgo.StringValue(instance.InstanceId))
 		return false
 	}
 
-	// If Name is unset, GetEC2ResourceNameTagValue returns error and zero value string
-	// Ignore this error and pass empty string to config.ShouldInclude
-	instanceName := util.GetEC2ResourceNameTagValue(instance.Tags)
+	var instanceName *string
+	if instance.Tags != nil {
+		instanceName = util.GetEC2ResourceNameTagValue(instance.Tags)
+		if instanceName == nil {
+			logging.Debugf("Name tag is nil for instance %s", awsgo.StringValue(instance.InstanceId))
+		}
+	} else {
+		logging.Debugf("Instance %s has no tags", awsgo.StringValue(instance.InstanceId))
+	}
+
 	return configObj.EC2.ShouldInclude(config.ResourceValue{
 		Name: instanceName,
 		Time: instance.LaunchTime,
@@ -78,10 +122,18 @@ func shouldIncludeInstanceId(instance *ec2.Instance, protected bool, configObj c
 }
 
 func (ei *EC2Instances) releaseEIPs(instanceIds []*string) error {
+	if instanceIds == nil {
+		logging.Debugf("InstanceIds is nil")
+		return nil
+	}
+
 	logging.Debugf("Releasing Elastic IP address(s) associated on instances")
 	for _, instanceID := range instanceIds {
+		if instanceID == nil {
+			logging.Debugf("Encountered a nil instance ID while releasing EIPs")
+			continue
+		}
 
-		// get the elastic ip's associated with the EC2's
 		output, err := ei.Client.DescribeAddressesWithContext(ei.Context, &ec2.DescribeAddressesInput{
 			Filters: []*ec2.Filter{
 				{
@@ -96,13 +148,21 @@ func (ei *EC2Instances) releaseEIPs(instanceIds []*string) error {
 			return err
 		}
 
+		if output == nil || output.Addresses == nil {
+			logging.Debugf("No addresses found for instance: %s", *instanceID)
+			continue
+		}
 		for _, address := range output.Addresses {
+			if address == nil || address.AllocationId == nil {
+				logging.Debugf("Encountered a nil address or AllocationId for instance: %s", *instanceID)
+				continue
+			}
 			_, err := ei.Client.ReleaseAddressWithContext(ei.Context, &ec2.ReleaseAddressInput{
 				AllocationId: address.AllocationId,
 			})
 
 			if err != nil {
-				logging.Debugf("An error happened while releasing the elastic ip address %s, error %v", *address.AllocationId, err)
+				logging.Debugf("Error releasing Elastic IP address %s: %v", *address.AllocationId, err)
 				continue
 			}
 			logging.Debugf("Released Elastic IP address %s from instance %s", *address.AllocationId, *instanceID)
@@ -112,15 +172,13 @@ func (ei *EC2Instances) releaseEIPs(instanceIds []*string) error {
 	return nil
 }
 
-// Deletes all non protected EC2 instances
+// Deletes all non-protected EC2 instances
 func (ei *EC2Instances) nukeAll(instanceIds []*string) error {
 	if len(instanceIds) == 0 {
 		logging.Debugf("No EC2 instances to nuke in region %s", ei.Region)
 		return nil
 	}
 
-	// release the attached elastic ip's
-	// Note: This should be done before terminating the EC2 instances
 	err := ei.releaseEIPs(instanceIds)
 	if err != nil {
 		logging.Debugf("[Failed EIP release] %s", err)
@@ -147,15 +205,19 @@ func (ei *EC2Instances) nukeAll(instanceIds []*string) error {
 			},
 		},
 	})
-	for _, instanceID := range instanceIds {
-		logging.Debugf("Terminated EC2 Instance: %s", *instanceID)
-	}
-
 	if err != nil {
 		logging.Debugf("[Failed] %s", err)
 		return errors.WithStackTrace(err)
 	}
 
+	for _, instanceID := range instanceIds {
+		if instanceID != nil {
+			logging.Debugf("Terminated EC2 Instance: %s", *instanceID)
+		} else {
+			logging.Debugf("Encountered a nil instance ID in the list of terminated instances")
+		}
+	}
+
 	logging.Debugf("[OK] %d instance(s) terminated in %s", len(instanceIds), ei.Region)
 	return nil
 }