image-proxy

Image proxy that can rasterize and resize images on-the-fly.

https://aaf.engineering/the-alliance-image-proxy/

API

The origin URL is specified by removing the protocol and appending it to the image proxy's host. For example:

https://image-proxy.example.com/files.example.com/image.svg

Options can be specified via query parameters:

• rasterize - If the source image is a vector image, the proxy will rasterize it.
• fit=[WIDTH]x[HEIGHT] - Scales down the source image to fit entirely within the given bounds.
• fill=[WIDTH]x[HEIGHT] - Scales down the source image to entirely fill the given bounds.
  • In addition to the fill parameter, crop can be specified to return an image of the exact width and height, cropped by the parameter. Options are:
    • crop=center
    • crop=left
    • crop=right
    • crop=top_left
    • crop=top
    • crop=top_right
    • crop=bottom_left
    • crop=bottom
    • crop=bottom_right
• format=jpg - Converts raster images to JPEG. Vector images may still be retreived unless rasterize is also specified.
  • quality=[QUALITY] can be used to control the quality of the JPEG encoding, where [QUALITY] is a number ranging from 1 to 100 (inclusive).

Configuration

You can specify a whitelist for allowed hosts via environment variable:

IMAGE_PROXY_ALLOWED_HOSTS=foo.example.com,bar.example.com,*.baz.example.com

Development

• Install librsvg. On macOS, you can brew install librsvg.

• Add librsvg include and lib paths to CGO_CFLAGS and CGO_LDFLAGS if necessary. For example, on macOS:

  export PKG_CONFIG_PATH=$(brew --prefix librsvg)
  export CGO_CFLAGS=$(pkg-config --cflags librsvg-2.0)
  export CGO_LDFLAGS=$(pkg-config --libs librsvg-2.0)
  

• Test and run via standard Go commands: dep ensure, go test ./..., go run main.go, etc.

Deployment

The easiest way to deploy is via the AWS Serverless Application Model (SAM). You can deploy the proxy with a click or two from the AWS Serverless Application Repository:

https://serverlessrepo.aws.amazon.com/applications/arn:aws:serverlessrepo:us-east-1:712375302725:applications~image-proxy

Alternatively, see the aws-sam directory for the do-it-yourself deployment.