How to Read & Write Barcode on AWS Lambda

This how-to article provides a comprehensive guide to setting up an AWS Lambda function using IronBarcode. In this guide, you will learn how to configure IronBarcode to read from and write barcodes to an S3 bucket.

How to Read & Write Barcode on AWS Lambda

Download a C# library to read and write barcode
Create and choose the project template
Modify the FunctionHandler code
Configure and deploy the project
invoke the function and check the results in S3

Installation

This article will use an S3 bucket, so the AWSSDK.S3 package is required.

Using IronBarcode Zip

If you are using IronBarcode ZIP, it is essential to set the temporary folder.

var awsTmpPath = @"/tmp/";
IronBarCode.Installation.DeploymentPath = awsTmpPath;

var awsTmpPath = @"/tmp/";
IronBarCode.Installation.DeploymentPath = awsTmpPath;

Dim awsTmpPath = "/tmp/"
IronBarCode.Installation.DeploymentPath = awsTmpPath

VB C#

The Microsoft.ML.OnnxRuntime package is required for reading barcodes. While writing barcodes works fine without it, the default mode for reading relies on machine learning (ML). If you switch to a reading mode that doesn't use ML, the package is not needed.

Start using IronBarcode in your project today with a free trial.

First Step:

Create an AWS Lambda Project

With Visual Studio, creating a containerized AWS Lambda is an easy process:

Install the AWS Tookit for Visual Studio
Select an 'AWS Lambda Project (.NET Core - C#)'
Select a '.NET 8 (Container Image)' blueprint, then select 'Finish'.

Select container image

Add Package Dependencies

The IronBarcode library in .NET 8 works on AWS Lambda without needing extra dependencies. To set it up, update the project's Dockerfile as follows:

FROM public.ecr.aws/lambda/dotnet:8

# install necessary packages
RUN dnf update -y

WORKDIR /var/task

# This COPY command copies the .NET Lambda project's build artifacts from the host machine into the image. 
# The source of the COPY should match where the .NET Lambda project publishes its build artifacts. If the Lambda function is being built 
# with the AWS .NET Lambda Tooling, the `--docker-host-build-output-dir` switch controls where the .NET Lambda project
# will be built. The .NET Lambda project templates default to having `--docker-host-build-output-dir`
# set in the aws-lambda-tools-defaults.json file to "bin/Release/lambda-publish".
#
# Alternatively Docker multi-stage build could be used to build the .NET Lambda project inside the image.
# For more information on this approach checkout the project's README.md file.
COPY "bin/Release/lambda-publish"  .

Modify the FunctionHandler Code

This example generates an EAN8 barcode, uploads it to an S3 bucket, and reads the newly created barcode. When using IronBarcode ZIP, configuring the temp folder is crucial because the library needs write permissions to copy the runtime folder from the DLLs.

using Amazon.Lambda.Core;
using Amazon.S3;
using Amazon.S3.Model;
using IronBarCode;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace IronBarcodeZipAwsLambda;

public class Function
{
    private static readonly IAmazonS3 _s3Client = new AmazonS3Client(Amazon.RegionEndpoint.APSoutheast1);

    /// <param name="context">The ILambdaContext that provides methods for logging and describing the Lambda environment.</param>
    /// <returns></returns>
    public async Task FunctionHandler(ILambdaContext context)
    {
        var awsTmpPath = @"/tmp/";
        IronBarCode.Installation.DeploymentPath = awsTmpPath;

        IronBarCode.License.LicenseKey = "IRONBARCODE-MYLICENSE-KEY-1EF01";

        string filename = Guid.NewGuid().ToString();

        string bucketName = "deploymenttestbucket";
        string objectKey = $"IronBarcodeZip/{filename}.png";

        try
        {
            // Creating a barcode is as simple as:
            var myBarcode = BarcodeWriter.CreateBarcode("1212345", BarcodeWriterEncoding.EAN8);

            // Use pdfData (byte array) as needed
            context.Logger.LogLine($"Barocde created.");

            // Upload the PDF to S3
            await UploadPngToS3Async(bucketName, objectKey, myBarcode.ToPngBinaryData());

            context.Logger.LogLine($"Barocde uploaded successfully to {bucketName}/{objectKey}");

            var resultFromByte = BarcodeReader.Read(myBarcode.ToPngBinaryData());

            foreach (var item in resultFromByte)
            {
                // Log the read value out
                context.Logger.LogLine($"Barcode value is = {item.Value}");
            }
        }
        catch (Exception e)
        {
            context.Logger.LogLine($"[ERROR] FunctionHandler: {e.Message}");
        }
    }
    // Function to upload the PNG file to S3
    private async Task UploadPngToS3Async(string bucketName, string objectKey, byte[] pdfBytes)
    {
        using (var memoryStream = new MemoryStream(pdfBytes))
        {
            var request = new PutObjectRequest
            {
                BucketName = bucketName,
                Key = objectKey,
                InputStream = memoryStream,
                ContentType = "image/png",
            };

            await _s3Client.PutObjectAsync(request);
        }
    }
}

using Amazon.Lambda.Core;
using Amazon.S3;
using Amazon.S3.Model;
using IronBarCode;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace IronBarcodeZipAwsLambda;

public class Function
{
    private static readonly IAmazonS3 _s3Client = new AmazonS3Client(Amazon.RegionEndpoint.APSoutheast1);

    /// <param name="context">The ILambdaContext that provides methods for logging and describing the Lambda environment.</param>
    /// <returns></returns>
    public async Task FunctionHandler(ILambdaContext context)
    {
        var awsTmpPath = @"/tmp/";
        IronBarCode.Installation.DeploymentPath = awsTmpPath;

        IronBarCode.License.LicenseKey = "IRONBARCODE-MYLICENSE-KEY-1EF01";

        string filename = Guid.NewGuid().ToString();

        string bucketName = "deploymenttestbucket";
        string objectKey = $"IronBarcodeZip/{filename}.png";

        try
        {
            // Creating a barcode is as simple as:
            var myBarcode = BarcodeWriter.CreateBarcode("1212345", BarcodeWriterEncoding.EAN8);

            // Use pdfData (byte array) as needed
            context.Logger.LogLine($"Barocde created.");

            // Upload the PDF to S3
            await UploadPngToS3Async(bucketName, objectKey, myBarcode.ToPngBinaryData());

            context.Logger.LogLine($"Barocde uploaded successfully to {bucketName}/{objectKey}");

            var resultFromByte = BarcodeReader.Read(myBarcode.ToPngBinaryData());

            foreach (var item in resultFromByte)
            {
                // Log the read value out
                context.Logger.LogLine($"Barcode value is = {item.Value}");
            }
        }
        catch (Exception e)
        {
            context.Logger.LogLine($"[ERROR] FunctionHandler: {e.Message}");
        }
    }
    // Function to upload the PNG file to S3
    private async Task UploadPngToS3Async(string bucketName, string objectKey, byte[] pdfBytes)
    {
        using (var memoryStream = new MemoryStream(pdfBytes))
        {
            var request = new PutObjectRequest
            {
                BucketName = bucketName,
                Key = objectKey,
                InputStream = memoryStream,
                ContentType = "image/png",
            };

            await _s3Client.PutObjectAsync(request);
        }
    }
}

Imports Amazon.Lambda.Core
Imports Amazon.S3
Imports Amazon.S3.Model
Imports IronBarCode

' Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
<Assembly: LambdaSerializer(GetType(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))>

Namespace IronBarcodeZipAwsLambda

	Public Class [Function]
		Private Shared ReadOnly _s3Client As IAmazonS3 = New AmazonS3Client(Amazon.RegionEndpoint.APSoutheast1)

		''' <param name="context">The ILambdaContext that provides methods for logging and describing the Lambda environment.</param>
		''' <returns></returns>
		Public Async Function FunctionHandler(ByVal context As ILambdaContext) As Task
			Dim awsTmpPath = "/tmp/"
			IronBarCode.Installation.DeploymentPath = awsTmpPath

			IronBarCode.License.LicenseKey = "IRONBARCODE-MYLICENSE-KEY-1EF01"

			Dim filename As String = Guid.NewGuid().ToString()

			Dim bucketName As String = "deploymenttestbucket"
			Dim objectKey As String = $"IronBarcodeZip/{filename}.png"

			Try
				' Creating a barcode is as simple as:
				Dim myBarcode = BarcodeWriter.CreateBarcode("1212345", BarcodeWriterEncoding.EAN8)

				' Use pdfData (byte array) as needed
				context.Logger.LogLine($"Barocde created.")

				' Upload the PDF to S3
				Await UploadPngToS3Async(bucketName, objectKey, myBarcode.ToPngBinaryData())

				context.Logger.LogLine($"Barocde uploaded successfully to {bucketName}/{objectKey}")

				Dim resultFromByte = BarcodeReader.Read(myBarcode.ToPngBinaryData())

				For Each item In resultFromByte
					' Log the read value out
					context.Logger.LogLine($"Barcode value is = {item.Value}")
				Next item
			Catch e As Exception
				context.Logger.LogLine($"[ERROR] FunctionHandler: {e.Message}")
			End Try
		End Function
		' Function to upload the PNG file to S3
		Private Async Function UploadPngToS3Async(ByVal bucketName As String, ByVal objectKey As String, ByVal pdfBytes() As Byte) As Task
			Using memoryStream As New MemoryStream(pdfBytes)
				Dim request = New PutObjectRequest With {
					.BucketName = bucketName,
					.Key = objectKey,
					.InputStream = memoryStream,
					.ContentType = "image/png"
				}

				Await _s3Client.PutObjectAsync(request)
			End Using
		End Function
	End Class
End Namespace

VB C#

Before the try block, the file destination is set to the IronBarcodeZip directory, with the name generated as a globally unique identifier (GUID). The CreateBarcode method is used to generate the barcode. Afterward, the PNG byte array is passed to the Read method to read the barcode. This demonstrates that the AWS Lambda function is capable of reading barcodes.

The Read method also accepts a BarcodeReaderOptions object, which you can customize to enable features such as reading multiple barcodes, targeting specific areas, using asynchronous and multithreaded processing, applying image correction filters, and much more.

Increase Memory and Timeout

The amount of memory allocated in the Lambda function will vary based on the size of the documents being processed and the number of documents processed simultaneously. As a baseline, set the memory to 512 MB and the timeout to 300 seconds in aws-lambda-tools-defaults.json.

"function-memory-size" : 512,
"function-timeout" : 300

When the memory is insufficient, the program will throw the error: 'Runtime exited with error: signal: killed.' Increasing the memory size can resolve this issue. For more details, refer to the troubleshooting article: AWS Lambda - Runtime Exited Signal: Killed.

Publish

To publish in Visual Studio, right-click on the project and select 'Publish to AWS Lambda...', then configure the necessary settings. You can read more about publishing a Lambda on the AWS website.