func findUnusedSecurityGroups()

in vpc-utils/awsutils.go [117:152]
30 lines of code
6 McCabe index (conditional complexity)

func findUnusedSecurityGroups(ctx context.Context, ec2Client *ec2.Client, sgIds []string) ([]string, error) {

	allNetworkInterfaces := []types.NetworkInterface{}
	securityGroupsInNetworkInterfaces := []string{}
	maxInterfaceResults := int32(100)

	firstNetworkInterfaces, err := ec2Client.DescribeNetworkInterfaces(ctx, &ec2.DescribeNetworkInterfacesInput{
		MaxResults: &maxInterfaceResults,
	})
	if err != nil {
		return nil, err
	}

	allNetworkInterfaces = append(allNetworkInterfaces, firstNetworkInterfaces.NetworkInterfaces...)

	var nextToken = firstNetworkInterfaces.NextToken
	for nextToken != nil {
		networkInterfaces, err := ec2Client.DescribeNetworkInterfaces(ctx, &ec2.DescribeNetworkInterfacesInput{
			MaxResults: &maxInterfaceResults,
			NextToken:  nextToken,
		})
		if err != nil {
			return nil, err
		}
		allNetworkInterfaces = append(allNetworkInterfaces, networkInterfaces.NetworkInterfaces...)
		nextToken = networkInterfaces.NextToken
	}

	for _, networkInterface := range allNetworkInterfaces {
		for _, group := range networkInterface.Groups {
			securityGroupsInNetworkInterfaces = append(securityGroupsInNetworkInterfaces, *group.GroupId)
		}
	}

	return common.Complement(sgIds, securityGroupsInNetworkInterfaces), nil
}