Pure Nginx Image Resize/Crop Microservice

Image cropping with gravity, resize and compress on the fly with nginx image_filter module. A tiny docker container to build your own Cloudinary-like service.

Nginx module - https://github.com/niiknow/docker-nginx-image-proxy/blob/master/build/src/ngx_http_image_filter_module.c

Features:

image crop offset, credit: https://github.com/bobrik/nginx_image_filter
/healthcheck endpoint
empty gif on other errors: 403, 404, 415, 500, 502, 503, 504
convert/force output to another format, support formats: bmp, jpg, png, gif, webp, and tiff
use custom ssl and saved config when you mount '/app' volume. nginx logs has also been redirect so you can backup, such as aws s3 sync. Just delete the default redirect to stdout/access.log and stderr/error.log files.
support international characters in URL
automatically follow redirect at origin

What does this solve?

You have a huge repository of images that need dynamic resize and cropping. Cloudinary can be expensive and redundant if you run your own CDN in front of this microservice.

And what it doesn't?

Unlike other libraries, this does not try to do every image transformation and/or caching.

For more advanced features such as: animated gif, face detection, auto image optimization, and others; we recommend using Cloudinary or similar service.
Outside of disk cache, there is no plan for other Caching methods. We recommend putting a CDN in front, such as (MaxCDN/StackPath/KeyCDN), to provide caching and easy SSL. We love StackPath/MaxCDN EdgeRules™.
If you want thumbnail caching to s3, just write a lambda function and use this server to generate your thumbnail. Upload the result to s3 with the same function.

build

docker build -t nginx-image-proxy .

run

docker run -d --restart=always -p 80:80 niiknow/nginx-image-proxy --env SERVER_CONF='https://gist.githubusercontent.com/...'

web

Example: http://imageproxy.yourdomain.com/rx/url-options/http://remote-host.com/image-path/image.jpg

or http as protocol default: http://imageproxy.yourdomain.com/rx/url-options/remote-host.com/image-path/image.jpg

Option Keys:

code: name - valid values - default
  q: quality - 1..100 - 96 (default to best in case it's previously optimized) 
  w: width - uint - null
  h: height - uint - null
  c: crop - null, 1 - null
  rz: resize - null, 1 - 1
  g: gravity - NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast *case-sensitive* - NorthWest
  e: sharpen - 1..100 - 0
  r: rotate - 0, 90, 180, 270 - 0
  ofmt: bmp, jpg, jpeg, png, gif, webp - force output format

Options Usages:

Options are a subset of Cloudinary. It's also very flexible and customizable.

Like Cloudinary with underscore (_) as separator: OptionKey_OptionValue - g_Center, w_100, h_100
Or without any separator: OptionKeyOptionValue - gCenter, w100, h100
Or in a QueryString: ?g=Center&w=100&h=100

And if that doesn't work, you can always use your custom nginx config by passing the config url into docker environment variable: SERVER_CONF