by Dsyko


Meteor Buildpack Horse


A heroku buildpack for Meteor v1+, designed to be as simple and readable as possible.

To use this with your meteor app and heroku:

  1. Set up your app to deploy to heroku with git.

  2. Set this repository as the buildpack URL:

     heroku buildpacks:set

3.a) Add the MongoLab addon:

    heroku addons:create mongolab


3.b) Add the URL of our mongo instance on INT

	heroku config:set MONGOHQ_URL=mongodb://DBIntURL
  1. Set the ROOT_URL environment variable. This is required for bundling and running the app. Either define it explicitly, or enable the Dyno Metadata labs addon to default to https://<appname>

     heroku config:set ROOT_URL="https://<appname>" # or other URL

Once that's done, you can deploy your app using this build pack any time by pushing to heroku:

git push heroku master


The following are some important environment variables for bundling and running your meteor app on heroku. Depending on your settings, you may need to override these on heroku. See heroku's documentation for how to set these.

  • ROOT_URL: The root URL for your app, needed for bundling as well as running. If you enable the Dyno Metadata labs addon and ROOT_URL is undefined, it will default to https://<appname>
  • MONGO_URL: The URL to mongodb. It not defined, it will default the value of MONGODB_URI, MONGOLAB_URI, or MONGOHQ_URL (in order). If you don't use mongolab as a regular addon (and none of the fallbacks are defined), you'll need to set this.
  • METEOR_APP_DIR: The relative path to the root of your meteor app within your git repository (i.e. the path to the directory that contains .meteor/). The buildpack will look in the root of your repository and app/ subdirectory; if you put your app anywhere else (like src/), define this variable to tell the buildpack where to look.
  • BUILDPACK_PRELAUNCH_METEOR: If your app uses packages that need to compile their assets on first run, you may need meteor to launch prior to bundling. If this applies for you, define BUILDPACK_PRELAUNCH_METEOR=1. Reference issue.
  • BUILDPACK_VERBOSE: Set BUILDPACK_VERBOSE=1 to enable verbose bash debugging during slug compilation. Only takes effect after the environment variables have been loaded.
  • BUILDPACK_CLEAR_CACHE: This buildpack stores the meteor installation in the CACHE_DIR to speed up subsequent builds. Set BUILDPACK_CLEAR_CACHE=1 to clear this cache on startup and after build is done.
  • BUILD_OPTIONS: Set to any additional options you'd like to add to the invocation of meteor build, for example --debug or --allow-incompatible-update.
  • NODEJS_PARAMS: additional parameters for running node binary. This can be used eg. for adjusting garbage collector settings by putting --optimize_for_size --max_old_space_size=460 --gc_interval=100 here


The basic buildpack should function correctly for any normal-ish meteor app, with or without npm-container. For extra steps needed for your particular build, just add shell scripts to the extra folder and they will get sourced into the build.

Extras included in this branch:

  • If MONGO_URL is empty, set it to the value of MONGODB_URI, MONGOLAB_URI, or MONGOHQ_URL (in order).
  • If ROOT_URL is empty and HEROKU_APP_NAME is available, set ROOT_URL to https://$

Where things go

This buildpack creates a directory .meteor/heroku_build ($COMPILE_DIR) inside the app checkout, and puts all the binaries and the built app in there. So it ends up having the usual unixy bin/, lib/, share etc subdirectories. Those directories are added to $PATH and $LD_LIBRARY_PATH appropriately.

So $COMPILE_DIR/bin etc are great places to put any extra binaries or stuff if you need to in custom extras.

Tips & Tricks

Please help us add tips and tricks to the wiki for further help, like usage with Dokku or other environments.

Why horse?

There are a gazillian forks and branches of various buildpacks remixing the words "heroku", "buildpack", and "meteor", many of which are abandoned or outdated or broken, and it's really hard to keep them straight.

So this one is the horse one.

README image credit: wikicommons contributor Arsdelicata