aws-lambda-image

An AWS Lambda Function to resize/reduce images automatically. When an image isput on AWS S3 bucket, this package will resize/reduce it and put to S3.

Requirements

• Node.js ( AWS Lambda supports versions of 8.10 or later )

Important Notice

From nodejs10.x, AWS Lambda doesn't bundle ImageMagick and image related libraries.

https://forums.aws.amazon.com/thread.jspa?messageID=906619&tstart=0

Therefore, if you'd deploy with nodejs10.x runtime (but we prefer and default as it), it needs to install AWS Lambda Layer with this function.This project can support it automatically, see LAYERS in detail.

Preparation

Clone this repository and install dependencies:

git clone git@github.com:ysugimoto/aws-lambda-image.git
cd aws-lambda-image
npm install .

When upload to AWS Lambda, the project will bundle only needed files - no devdependencies will be included.

Configuration

Configuration file you will find under the name config.json in project root.It's copy of our example file config.json.sample. More or less it looks like:

{
  "bucket": "your-destination-bucket",
  "backup": {
      "directory": "./original"
  },
  "reduce": {
      "directory": "./reduced",
      "prefix": "reduced-",
      "quality": 90,
      "acl": "public-read",
      "cacheControl": "public, max-age=31536000"
  },
  "resizes": [
    {
      "size": 300,
      "directory": "./resized/small",
      "prefix": "resized-",
      "cacheControl": null
    },
    {
      "size": 450,
      "directory": "./resized/medium",
      "suffix": "_medium"
    },
    {
      "size": "600x600^",
      "gravity": "Center",
      "crop": "600x600",
      "directory": "./resized/cropped-to-square"
    },
    {
      "size": 600,
      "directory": "./resized/600-jpeg",
      "format": "jpg",
      "background": "white"
    },
    {
      "size": 900,
      "directory": "./resized/large",
      "quality": 90
    }
  ]
}

Configuration Parameters

Note that the optmizers option will force override its command arguments, so if you define these configurations, we don't care any more about how optimizer works.

Testing Configuration

If you want to check how your configuration will work, you can use:

npm run test-config

Installation

Setup

To use the automated deployment scripts you will need to haveaws-cli installed and configured.

Deployment scripts are pre-configured to use some default values for the Lambdaconfiguration. I you want to change any of those just use:

npm config set aws-lambda-image:profile default
npm config set aws-lambda-image:region eu-west-1
npm config set aws-lambda-image:memory 1280
npm config set aws-lambda-image:timeout 5
npm config set aws-lambda-image:name lambda-function-name
npm config set aws-lambda-image:role lambda-execution-role

Note that aws-lambda-image:name and aws-lambda-image:role are optional.If you want to change lambda function name or execution role, type above commands before deploy.

And make sure AWS Lambda Layer has installed in your account/region.See LAYERS for instructions.

Deployment

Command below will deploy the Lambda function on AWS, together with setting uproles and policies.

npm run deploy

Notice: Because there are some limitations in Claudia.js support forpolicies, which could lead to issues with Access Denied when processingimages from one bucket and saving them to another, we have decided to introducesupport for custom policies.

Custom policies

Policies which should be installed together with our Lambda function are storedin policies/ directory. We keep there policy that grants access to allbuckets, which is preventing possible errors with Access Denied describedabove. If you have any security-related concerns, feel free to change the:

"Resource": [
    "*"
]

in the policies/s3-bucket-full-access.json to something more restrictive,like:

"Resource": [
    "arn:aws:s3:::destination-bucket-name/*"
]

Just keep in mind, that you need to make those changes before you do thedeployment.

Adding S3 event handlers

To complete installation process you will need to take one more action. It willallow you to install S3 Bucket event handler, which will send information aboutall uploaded images directly to your Lambda function.

npm run add-s3-handler --s3_bucket="your-bucket-name" --s3_prefix="directory/" --s3_suffix=".jpg"

You are able to install multiple handlers per Bucket. So, to add handler for PNGfiles you just need to re-run above command with different suffix, ie:

npm run add-s3-handler --s3_bucket="your-bucket-name" --s3_prefix="directory/" --s3_suffix=".png"

Adding SNS message handlers

As an addition, you can also setup and SNS message handler in case you wouldlike to process S3 events over an SNS topic.

npm run add-sns-handler --sns_topic="arn:of:SNS:topic"

Updating

To update Lambda with you latest code just use command below. Script will buildnew package and automatically publish it on AWS.

npm run update

More

For more scripts look into package.json.

Complete / Failed hooks

You can handle resize/reduce/backup process on success/error result onindex.js. ImageProcessor::run will return Promise object, run youroriginal code:

processor.run(config)
.then(function(proceedImages)) {

    // Success case:
    // proceedImages is list of ImageData instance on you configuration

    /* your code here */

    // notify lambda
    context.succeed("OK, numbers of " + proceedImages.length + " images has proceeded.");
})
.catch(function(messages) {

    // Failed case:
    // messages is list of string on error messages

    /* your code here */

    // notify lambda
    context.fail("Woops, image process failed: " + messages);
});

Image resize

• ImageMagick (installed on AWS Lambda)

Image reduce

• cjpeg
• jpegoptim
• pngquant
• gifsicle

License

MIT License.

Author

Yoshiaki Sugimoto

Image credits

Thanks for testing fixture images:

• pngimg
• pakutaso