squasher

Squash

Simple HTTP endpoint to squash images - designed to run as a Docker container, but can run standalone

Installation

Since the module is not yet available on npm, you must install this manually using git, for instance:

$ npm install abstractvector/squasher

Squash exposes an HTTP server on port 3000.

Usage

The HTTP endpoint exists at the root / and expects to be POSTed an image file. You should ensure that the Content-Type header is correct.

For a very simple usage, you can use curl:

$ curl -v \
       -H 'Content-Type: image/jpeg' \
       -H 'Accept: image/webp,image/apng,image/*,*/*;q=0.8' \
       --data-binary @/path/to/my/image.jpg \
       http://localhost:3000 1>/dev/null

Image Formats

Squasher will use the Accept header to decide what image type to return - it will return the smallest file size of the available image type: JPEG, PNG or WebP.

Because many browsers specify image/* in their Accept header but don't actually support image/webp, Squasher does a strict check looking for image/webp to be explicitly stated. If image/webp is not explicitly stated then it is assumed that the client does not support WebP. JPEG and PNG support are still allowed by image/* however.

Operations

Operations are available to manipulate the image before it is returned. These are specified on the URL and you can chain multiple together.

Size

Format: /size=<width>x<height>

Example	Action
/size=300x200	Resizes the image to a maximum of 300x200, cropping if it exceeds this
/size=300	Resizes the width to 300px whilst retaining the aspect ratio
/size=x200	Resizes the height to 200px whilst retaining the aspect ratio

To Do

• Add unit tests
• Document crop feature
• Add more image manipulation features
• Improve error handling
• Allow configuration, especially for compression
• Support restrictions for allowed operations
• Add caching