bytescale / aws-lambda-image-magick-resize-example

AWS Lambda image resize example (using ImageMagick to perform the image processing).

AWS Lambda Image Resize Example (with ImageMagick)

This repository deploys an AWS Lambda Function that resizes images using ImageMagick.

Blog post: https://www.bytescale.com/blog/aws-lambda-image-resize/

Quick Start

Important:

• Replace my-lambda-function-code and my-images with unique S3 bucket names!

Deploying the Lambda Function

1. Checkout the repository:

   git clone [e-mail]:bytescale/aws-lambda-image-magick-resize-example.git
   
   cd aws-lambda-image-magick-resize-example

2. Install NPM dependencies:

   npm install

3. Create the S3 bucket stack (remember: change the bucket names in ParameterValue below):

   aws cloudformation create-stack \
     --stack-name my-bucket-stack \
     --parameters ParameterKey=LambdaCodeBucketName,ParameterValue=my-lambda-function-code \
                  ParameterKey=ImageBucketName,ParameterValue=my-images \
     --template-body file://buckets-cloudformation.yml

4. Update function.js > imageBucketName to your image bucket's name.

5. Upload the Lambda Function's code:

   zip -ry function-dist.zip .
   aws s3 cp function-dist.zip s3://my-lambda-function-code/AwsLambdaImageResizeExample.zip

6. Deploy the Lambda Function (remember: change the bucket names in ParameterValue below):

   aws cloudformation create-stack \
     --stack-name my-image-resize-lambda \
     --parameters ParameterKey=LambdaCodeBucketName,ParameterValue=my-lambda-function-code \
                  ParameterKey=ImageBucketName,ParameterValue=my-images \
     --template-body file://function-cloudformation.yml \
     --capabilities CAPABILITY_NAMED_IAM

7. Wait for the Lambda Function's stack to complete:

   aws cloudformation describe-stack-events \
     --stack-name my-image-resize-lambda

   Note: the latest event should read "ResourceStatus": "CREATE_COMPLETE".

Invoking the function

1. Upload the image to resize:

   aws s3 cp test-image.jpg s3://my-images/original-image.jpg

2. Invoke the function:

   aws lambda invoke \
     --function-name AwsLambdaImageResizeExample \
     function-result.json

3. "See" the result:

   cat function-result.json

   Outputs:

   {
     "isBase64Encoded": true,
     "statusCode": 200,
     "headers": {
       "content-type": "image/jpg"
     },
     "body": "/9j/4AAQSkZJRg...9k="
   }

   Note: AWS Lambda only supports JSON responses. body contains the resized image as a base64-encoded string: to return the raw image, you'll need to put API Gateway in front of the Lambda function.