aws-lambda-image

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

Requirements

• node.js ( AWS Lambda working version is 4.3.2 )
• make

Installation

Clone this repository and install dependencies:

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

Packaging

AWS Lambda accepts zip archived package. To create it, run make lambda task simply.

$ make lambda

It will create aws-lambda-image.zip at project root. You can upload it.

Configuration

This works with config.json put on project root. There is config.json.sample as example. You can copy to use it.

$ cp config.json.sample config.json

Configuration is simple, see below:

{
  "bucket": "your-destination-bucket",
  "backup": {
      "directory": "./original",
  },
  "reduce": {
      "directory": "./reduced",
      "prefix": "reduced-",
      "quality": 90
  },
  "resizes": [
    {
      "size": 300,
      "directory": "./resized/small",
      "prefix": "resized-",
    },
    {
      "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

name	field	type	description
bucket	-	String	Destination bucket name at S3 to put processed image. If not supplied, it will use same bucket of event source.
backup	-	Object	Backup original file setting.
	directory	String	Image directory path. When starts with ./ relative to the source, otherwise creates a new tree.
	bucket	String	Destination bucket to override. If not supplied, it will use bucket setting.
reduce	-	Object	Reduce setting following fields.
	directory	String	Image directory path. When starts with ./ relative to the source, otherwise creates a new tree.
	prefix	String	Append filename prefix if supplied.
	quality	Number	Determine reduced image quality ( enables only JPG ).
	bucket	String	Destination bucket to override. If not supplied, it will use bucket setting.
resize	-	Array	Resize setting list of following fields.
	background	String	Background color to use for transparent pixels when destination image doesn't support transparency.
	bucket	String	Destination bucket to override. If not supplied, it will use bucket setting.
	crop	String	Dimensions to crop the image. See ImageMagick crop documentation.
	directory	String	Image directory path. When starts with ./ relative to the source, otherwise creates a new tree.
	prefix	String	Append filename prefix if supplied.
	format	String	Image format override. If not supplied, it will leave the image in original format.
	gravity	String	Changes how size and crop. See ImageMagick gravity documentation.
	quality	Number	Determine reduced image quality ( enables only JPG ).
	size	String	Image dimensions. See ImageMagick geometry documentation.
	orientation	Boolean	Auto orientation if value is true.

If you want to check how this works with your configuration, you can use configtest:

$ make configtest

Complete / Failed hooks

You can handle resize/reduce/backup process on success/error result on index.js. ImageProcessor::run will return Promise object, run your original 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
• pngquant
• pngout

License

MIT License.

Author

Yoshiaki Sugimoto

Image credits

Thanks for testing fixture images:

• http://pngimg.com/
• https://www.pakutaso.com/