imgflo-server

imgflo-server is an image-processing server with HTTP built using the imgflo dataflow runtime.

Changelog

See ./CHANGES.md

License

MIT

Note: GEGL itself is under LGPLv3.

About

The imgflo server provides a HTTP API for processing images:

GET /graphs/mygraph?input=http://example.com/input-image.png&attr1=value1&....

When the server gets the request, it will:

1. Download the specified input image over HTTP(s)
2. Find and load the graph mygraph
3. Set attribute,value pairs as IIPs to the exported ports of the graph
4. Processes the graph using a runtime*
5. Stores the output image to disk
6. Serve the output image over HTTP

Note: In step 4, currently a new runtime is spawned for each request, and communication done through stdin. In the future, the runtime will be a long-running worker, and communication done using the FBP runtime protocol.

*In addition to supporting the native imgflo runtime, the server can also execute graphs built with NoFlo w/ noflo-canvas.

API usage

JavaScript helpers

1. Forming valid imgflo urls: imgflo-url
2. Creating responsive images using media-query: rig

Creating new image processing graphs

imgflo-server can easily be extended with new image processing pipelines, either using a text-based DSL or Flowhub node-based visual IDE.

See Adding Graphs

Hosted public instance

Currently our deployed instance is only for The Grid. If you are interested in access to hosted version, send us an email: support@thegrid.io

Deploying to Heroku

Server

Register/log-in with Heroku, and create a new app. First one is free.

After creating the app, login at Heroku:

heroku login

Clone imgflo-server:

git clone https://github.com/jonnor/imgflo-server.git
cd imgflo-server

Add YOURAPP as remote:

heroku git:remote -a YOURAPP

Specify the multi buildpack with build-env support, either at app creation time, in Heroku webui or using

heroku config:set BUILDPACK_URL=https://github.com/mojodna/heroku-buildpack-multi.git#build-env

Configure some environment variables (hostname, port and local image cache):

heroku config:set HOSTNAME=YOURAPP.herokuapp.com
heroku config:set PORT=80

Deploy, will take ~1 minute

git push heroku master

You should now see the imgflo server running at http://YOURAPP.herokuapp.com

If everything is OK you should be able to see a generative image at http://YOURAPP.herokuapp.com/graph/delaunay_triangles?seed=foobar&height=800&width=600

Developing and running locally

Note: imgflo has only been tested on GNU/Linux systems. Root is not needed for any of the build.

Pre-requisites

imgflo requires git master of GEGL and BABL, as well as a custom version of libsoup. It is recommended to let make setup this for you, but you can use existing checkouts by customizing PREFIX. You only need to install the dependencies once, or when they have changed.

git submodule update --init
make dependencies

If you are on an older distribution, you may also need a newer glib version

# make glib # only for older distros, where GEGL fails to build due to too old glib

Install node.js dependencies

npm install

Build

Now you can build & install imgflo itself

make install

To verify that things are working, run the test suite

make check

Running server

node index.js

You should see your server running at http://localhost:8080