Lift and shift a web app to serverlessStorage migration2 min

In the original application, when a new product is created, a new image is uploaded to the Node.js/Express server. However, now the application resides in a Lambda function. The code (and files) that are part of that function cannot change, unless the function is redeployed. Consequently, you must separate the user storage from the server code.

For doing this, there are a couple of solutions: using Amazon Elastic File System (EFS) or Amazon S3. EFS is a file storage, and you can use that to have a dynamic storage where you upload the new images. Using EFS won’t change much of the code, as the original implementation is using a directory inside the server as EFS provides. However, using EFS adds more complexity to the application, as functions that use EFS must be inside an Amazon Virtual Private Cloud (Amazon VPC).

Using S3 to upload your images to the application is simpler, as it only requires that an S3 bucket exists. For doing this, you must refactor the application, from uploading the image to the application API to use the AWS Amplify library that uploads and gets images from S3.

export function uploadImage(file) {
    const fileName = `uploads/${file.name}`;

    const request = Storage.put(fileName, file).then((result) => {
        return {
            image: fileName,
            success: true,
        };
    });

    return {
        type: IMAGE_UPLOAD,
        payload: request,
    };
}

An important benefit of using S3 is that you can also use Amazon CloudFront to accelerate the retrieval of the images from the cloud.

In this way, you can speed up the loading time of your page. You can see how this is implemented step by step in this video.


Created by:

Marcia Villalba
Marcia VillalbaMarcia hosts the FooBar Serverless YouTube channel where she publishes content every week related to serverless and the cloud. She has been designing and developing software professionally for 15 years and worked in all the different stages of building scaling and performant software.