by EATechnologies

GitHub Readme.md


A generic builpack to deploy libraries on Heroku

This buildpack is built to be used through heroku-buildpack-multi. In your app you need to:

heroku config:set BUILDPACK_URL=https://github.com/ddollar/heroku-buildpack-multi

Then, create a .buildpacks file inside your app:


See the documentation of heroku-build-multi for a detailed explanation how to use it.

Decrease the slug size

It is possible to make some corrections to the original heroku buildpack. In particular, add check for a .buildpack-ignore and remove files not needed, decreasing the slug size. This is useful in particular fro removing temporary or test directories from Ruby Gems.

Build on Vulcan

Scripts to build on Vulcan is available under the /support folder. it is necessary to create beforehands a vulcan build server.

gem install vulcan
vulcan create _your_vulcan_server_

The binaries are available at the moment are:

  1. Tesseract-OCR (3.02)

  2. OpenCV (2.4.5)

  3. CMake (2.8.11)

  4. ImageMagick (6.8.5-8)


A file called .buildpacks_bin_download need to be added containing the full path of the tar.gz file with the binaries compiled with Vulcan, and options if necessary (options specified below).

binary binary_path binary_options

binary is the name of the binary/library to install, binary_path is the path were the executables/libraries are stored,. Example: https://s3.amazonaws.com/_your_builded_bins.tar.gz

It is possible to access the binaries compiled with Vulcan and hosted on Heroku Vulcan server, with a similar configuration. As path it is necessary to specify the result of the vulcan build process, a path similar to http://_your_vulcan_server_.herokuapp.com/output/_compiled_hash

Build on the fly

A file called .buildpacks_bin_build need to be added containing the name of the binaries to be compiled, and options if necessary (options specified below).

binary binary_options

Note that the on the fly compile might take long time.

Special config for the binaries


It is necessary to specify an additional version number (necessary for getting the training datas) An optional comma-separated string can be added for download additional languages than English

tesseract-ocr https://s3.amazonaws.com/tesseract-ocr/heroku/tesseract-ocr-3.02.02.tar.gz 3.02 eng,jpn


A patch is made to correctly export the pkgconfig file for production enviroments. It is possible to build OpenCV with a pre-build version of CMake as follows:

vulcanBuild opencv --cmake cmake_prebuilt_lib

For using OpenCV with Nodejs, a dedicated buildpack-multi is available here.

In your app you need to set the buildpack to the customized buildpack:

heroku config:set BUILDPACK_URL=https://github.com/marcolinux/heroku-buildpack-multi

Then, create a .buildpacks file inside your app:


The order is important, the library need to be installed before calling the Nodejs buildpack Finally, a file called .buildpacks_bin_download need to be added containing the full path of the tar.gz file with the libraries compile with Vulcan

opencv _vulcan_or_amazon_s3_path


MIT License. Copyright 2013 Marco Azimonti.