by dsablic

GitHub Readme.md

Heroku Buildpack: Run

Run custom commands during the build process.


This buildpack allows to execute arbitrary commands on the build dyno during the build process by running one or more user-supplied Bash scripts.

Basic Usage

Add the buildpack to your app:

heroku buildpacks:add https://github.com/weibeld/heroku-buildpack-run

Create the file buildpack-run.sh in the root directory of your app. For example:

# This is buildpack-run.sh
echo "Hello World"

Now push your app to Heroku as usual. The buildpack-run.sh script will be run by Bash during the build.

Note that it is not required to add a #!/bin/bash to your script (but if it's there, it doesn't do any harm).

Usage with Another Filename

If you want to use a script with a different name than buildpack-run.sh, then you can specify this file in the Heroku app config variable BUILDPACK_RUN.

For example, if your script is called script.sh:

heroku config:set BUILDPACK_RUN=script.sh

The specified value must be a filename relative to the root directory of your app, so it could also be something like bin/script.sh or ./script.sh.

Note that the BUILDPACK_RUN config variable takes precedence over the default buildpack-run.sh file. So, if you have both, a BUILDPACK_RUN variable and a buildpack-run.sh file, then only the file in BUILDPACK_RUN will be executed.

Usage with Multiple Files

You can specify multiple files in BUILDPACK_RUN by separating them with colons:

heroku config:set BUILDPACK_RUN=script1.sh:script2.sh:script3.sh

The scripts will be executed sequentially in the specified order.

Usage with Arguments

You can specify arguments to your scripts, just as you would on the command line.

For, example, you can do something like this:

heroku config:set BUILDPACK_RUN="script1.sh 1 2 3:script2.sh hey 'hello world'"

And this will execute bash script1.sh 1 2 3 and then bash script2.sh hey 'hello world'.

Build Environment Variables

The following variables holding information about the Heroku build environment are accessible to your scripts:

  • BUILD_DIR: absolute path of your app's root directory on the build dyno
  • CACHE_DIR: directory on the build dyno that persists between builds
  • ENV_DIR: directory containing files for the app's Heroku config variables

The working directory for your scripts is BUILD_DIR, which is the root directory of your app.


Licensed under the MIT License. See LICENSE.md file.