How to Read & Write Barcode on AWS Lambda

Installation

Für diesen Artikel wird ein S3-Bucket verwendet. Daher ist das AWSSDK.S3-Paket erforderlich.

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

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

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

Erstellen Sie ein AWS Lambda-Projekt

Mit Visual Studio ist die Erstellung eines containerisierten AWS Lambda ein einfacher Prozess:

• Installieren Sie das AWS Toolkit für Visual Studio
• Wählen Sie ein 'AWS Lambda Project (.NET Core - C#)'
• Wählen Sie eine '.NET 8 (Container Image)' Blaupause aus und wählen dann 'Fertigstellen'.

Abhängigkeitspakete hinzufügen

Die IronBarcode-Bibliothek in .NET 8 funktioniert auf AWS Lambda ohne zusätzliche Abhängigkeiten. Um es einzurichten, aktualisieren Sie die Docker-Datei des Projekts wie folgt:

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"  .

Ändern Sie den FunctionHandler-Code

Dieses Beispiel generiert einen EAN8-Barcode, lädt ihn in einen S3-Bucket hoch und liest den neu erstellten Barcode. Beim Verwenden von IronBarcode ZIP ist die Konfiguration des temporären Ordners entscheidend, da die Bibliothek Schreibberechtigungen benötigt, um den Laufzeitordner von den DLLs zu kopieren.

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

Vor dem try-Block wird das Dateiziel auf das IronBarcodeZip-Verzeichnis gesetzt, wobei der Name als global eindeutiger Bezeichner (GUID) generiert wird. Methode CreateBarcode wird zur Generierung des Barcodes verwendet. Danach wird das PNG-Byte-Array an die Read-Methode übergeben, um den Barcode zu lesen. Dies zeigt, dass die AWS Lambda-Funktion in der Lage ist, Barcodes zu lesen.

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.

Erhöhen Sie Speicher und Timeout

Die Menge des in der Lambda-Funktion zugewiesenen Speichers hängt von der Größe der zu verarbeitenden Dokumente und der Anzahl der gleichzeitig verarbeiteten Dokumente ab. Als Ausgangspunkt stellen Sie den Speicher auf 512 MB und das Timeout auf 300 Sekunden in aws-lambda-tools-defaults.json ein.

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

Wenn der Speicher nicht ausreicht, wirft das Programm den Fehler: 'Runtime exited with error: signal: killed.' Eine Erhöhung der Speichergröße kann dieses Problem lösen. Weitere Details finden Sie im Artikel zur Fehlerbehebung: AWS Lambda - Runtime Exited Signal: Killed.

Veröffentlichen

Um in Visual Studio zu veröffentlichen, klicken Sie mit der rechten Maustaste auf das Projekt und wählen 'Publish to AWS Lambda...', dann die erforderlichen Einstellungen konfigurieren. Weitere Informationen zum Veröffentlichen von Lambda finden Sie auf der AWS-Website.

Probieren Sie es aus!

Sie können die Lambda-Funktion entweder über die Lambda-Konsole oder über Visual Studio aktivieren.