How to Read & Write Barcode on AWS Lambda

Installation

Cet article utilisera un compartiment S3, donc le package AWSSDK.S3 est requis.

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

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

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

Créer un projet AWS Lambda

Avec Visual Studio, créer un AWS Lambda containerisé est un processus simple :

• Installer le AWS Toolkit pour Visual Studio
• Sélectionnez un 'Projet AWS Lambda (.NET Core - C#)'
• Sélectionnez un modèle '.NET 8 (Image de Conteneur)', puis sélectionnez 'Terminer'.

Ajouter des dépendances de package

La bibliothèque IronBarcode dans .NET 8 fonctionne sur AWS Lambda sans nécessiter de dépendances supplémentaires. Pour l'installer, mettez à jour le fichier Docker du projet comme suit :

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 check out the project's README.md file.
COPY "bin/Release/lambda-publish"  .

Modifier le code de FunctionHandler

Cet exemple génère un code-barres EAN8, le télécharge vers un compartiment S3 et lit le code-barres nouvellement créé. Lors de l'utilisation d'IronBarcode ZIP, il est crucial de configurer le dossier temporaire car la bibliothèque a besoin de permissions d'écriture pour copier le dossier runtime à partir des 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);

    /// <summary>
    /// AWS Lambda Function Handler. It generates a barcode, uploads it to S3, and then reads it.
    /// </summary>
    /// <param name="context">The ILambdaContext that provides methods for logging and describing the Lambda environment.</param>
    public async Task FunctionHandler(ILambdaContext context)
    {
        var awsTmpPath = @"/tmp/";
        IronBarCode.Installation.DeploymentPath = awsTmpPath;

        // Set your IronBarcode license key here
        IronBarCode.License.LicenseKey = "IRONBARCODE-MYLICENSE-KEY-1EF01";

        string filename = Guid.NewGuid().ToString();
        string bucketName = "deploymenttestbucket";
        string objectKey = $"IronBarcodeZip/{filename}.png";

        try
        {
            // Creating a barcode with EAN8 encoding
            var myBarcode = BarcodeWriter.CreateBarcode("1212345", BarcodeWriterEncoding.EAN8);

            context.Logger.LogLine($"Barcode created.");

            // Upload the PNG image of the barcode to the specified S3 bucket
            await UploadPngToS3Async(bucketName, objectKey, myBarcode.ToPngBinaryData());
            context.Logger.LogLine($"Barcode uploaded successfully to {bucketName}/{objectKey}");

            // Read and log the barcode value from the PNG binary data
            var resultFromByte = BarcodeReader.Read(myBarcode.ToPngBinaryData());
            foreach (var item in resultFromByte)
            {
                context.Logger.LogLine($"Barcode value is = {item.Value}");
            }
        }
        catch (Exception e)
        {
            context.Logger.LogLine($"[ERROR] FunctionHandler: {e.Message}");
        }
    }

    /// <summary>
    /// Uploads a PNG byte array to the specified S3 bucket.
    /// </summary>
    /// <param name="bucketName">The name of the S3 bucket.</param>
    /// <param name="objectKey">The object key for the uploaded file in the bucket.</param>
    /// <param name="pdfBytes">Byte array of the PNG to be uploaded.</param>
    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);

    /// <summary>
    /// AWS Lambda Function Handler. It generates a barcode, uploads it to S3, and then reads it.
    /// </summary>
    /// <param name="context">The ILambdaContext that provides methods for logging and describing the Lambda environment.</param>
    public async Task FunctionHandler(ILambdaContext context)
    {
        var awsTmpPath = @"/tmp/";
        IronBarCode.Installation.DeploymentPath = awsTmpPath;

        // Set your IronBarcode license key here
        IronBarCode.License.LicenseKey = "IRONBARCODE-MYLICENSE-KEY-1EF01";

        string filename = Guid.NewGuid().ToString();
        string bucketName = "deploymenttestbucket";
        string objectKey = $"IronBarcodeZip/{filename}.png";

        try
        {
            // Creating a barcode with EAN8 encoding
            var myBarcode = BarcodeWriter.CreateBarcode("1212345", BarcodeWriterEncoding.EAN8);

            context.Logger.LogLine($"Barcode created.");

            // Upload the PNG image of the barcode to the specified S3 bucket
            await UploadPngToS3Async(bucketName, objectKey, myBarcode.ToPngBinaryData());
            context.Logger.LogLine($"Barcode uploaded successfully to {bucketName}/{objectKey}");

            // Read and log the barcode value from the PNG binary data
            var resultFromByte = BarcodeReader.Read(myBarcode.ToPngBinaryData());
            foreach (var item in resultFromByte)
            {
                context.Logger.LogLine($"Barcode value is = {item.Value}");
            }
        }
        catch (Exception e)
        {
            context.Logger.LogLine($"[ERROR] FunctionHandler: {e.Message}");
        }
    }

    /// <summary>
    /// Uploads a PNG byte array to the specified S3 bucket.
    /// </summary>
    /// <param name="bucketName">The name of the S3 bucket.</param>
    /// <param name="objectKey">The object key for the uploaded file in the bucket.</param>
    /// <param name="pdfBytes">Byte array of the PNG to be uploaded.</param>
    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)

		''' <summary>
		''' AWS Lambda Function Handler. It generates a barcode, uploads it to S3, and then reads it.
		''' </summary>
		''' <param name="context">The ILambdaContext that provides methods for logging and describing the Lambda environment.</param>
		Public Async Function FunctionHandler(ByVal context As ILambdaContext) As Task
			Dim awsTmpPath = "/tmp/"
			IronBarCode.Installation.DeploymentPath = awsTmpPath

			' Set your IronBarcode license key here
			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 with EAN8 encoding
				Dim myBarcode = BarcodeWriter.CreateBarcode("1212345", BarcodeWriterEncoding.EAN8)

				context.Logger.LogLine($"Barcode created.")

				' Upload the PNG image of the barcode to the specified S3 bucket
				Await UploadPngToS3Async(bucketName, objectKey, myBarcode.ToPngBinaryData())
				context.Logger.LogLine($"Barcode uploaded successfully to {bucketName}/{objectKey}")

				' Read and log the barcode value from the PNG binary data
				Dim resultFromByte = BarcodeReader.Read(myBarcode.ToPngBinaryData())
				For Each item In resultFromByte
					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

		''' <summary>
		''' Uploads a PNG byte array to the specified S3 bucket.
		''' </summary>
		''' <param name="bucketName">The name of the S3 bucket.</param>
		''' <param name="objectKey">The object key for the uploaded file in the bucket.</param>
		''' <param name="pdfBytes">Byte array of the PNG to be uploaded.</param>
		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

Avant le bloc try, la destination du fichier est définie sur le répertoire IronBarcodeZip, avec un nom généré comme un identifiant unique global (GUID). La méthode CreateBarcode est utilisée pour générer le code-barres. Ensuite, le tableau d'octets PNG est passé à la méthode Read pour lire le code-barres. Cela démontre que la fonction AWS Lambda est capable de lire des codes-barres.

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.

Augmenter la mémoire et le délai d'expiration

La quantité de mémoire allouée dans la fonction Lambda variera en fonction de la taille des documents traités et du nombre de documents traités simultanément. Pour commencer, réglez la mémoire sur 512 Mo et le délai d'expiration sur 300 secondes dans aws-lambda-tools-defaults.json.

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

Lorsque la mémoire est insuffisante, le programme génère l'erreur : 'Runtime exited with error: signal: killed.' Augmenter la taille de la mémoire peut résoudre ce problème. Pour plus de détails, consultez l'article de dépannage : AWS Lambda - Runtime Exited Signal: Killed.

Publier

Pour publier dans Visual Studio, cliquez avec le bouton droit sur le projet et sélectionnez 'Publier sur AWS Lambda...', puis configurez les paramètres nécessaires. Vous pouvez en savoir plus sur la publication d'une Lambda sur le site Web AWS.

Essayez-le!

Vous pouvez activer la fonction Lambda soit via la console Lambda soit via Visual Studio.