cb-heroku-buildpack

by fylfot

GitHub Readme.md

Heroku Buildpack: Chicagoboss

Repo contains a modernized Heroku buildpack for Erlang, specifically for chicagoboo. It's a mixture of Erlang Buildpack and ChicagoBoss Buildpack.

Why another Buildpack?... And specifically for chicagoboss

If you, dear developer, investigate Heroku's original buildpack for Erlang, you will see it's nearly 4 years old. This new iteration, version 20.1, is for use with the ChicagoBoss framework and complies with all modern Heroku requirements. So... basically everything should work, but please read requirements before using!

Requirements

  1. For the buildpack to work correctly, your repo with ChicagoBoss config should be flat with no subdirectories containing app code, located directly in root.

  2. You need to create Procfile in your repo (example in this repo). This Procfile will not use ChicagoBoss default integrated script, using instead init.sh, because it must be customzied slight to work on Heroku by adding:

  • -noinput - that will prevent app crash after deploy/restart on heroku (Heroku doesn't have stdin source, so if erl will ask for that, you will get segfault).

  • -simple_bridge port $PORT - here we are forcing port number from ENV from heroku, so app will be visible from network.

  1. In boss.config please check APPLICATION CONFIGURATIONS section, here is {path, ...} tuple, that should be {path, "/app"}, because it's default folder where heroku code lives.

  2. And regarding to step 3. check other path's to be configured correctly.

Procfile example:

web: erl -pa ./deps/aleppo/ebin -pa ./deps/binpp/ebin -pa ./deps/boss/ebin -pa ./deps/boss_db/ebin -pa ./deps/boss_test/ebin -pa ./deps/color/ebin -pa ./deps/cowboy/ebin -pa ./deps/cowlib/ebin -pa ./deps/ddb/ebin -pa ./deps/dh_date/ebin -pa ./deps/dynamic_compile/ebin -pa ./deps/epgsql/ebin -pa ./deps/eredis/ebin -pa ./deps/erlando/ebin -pa ./deps/erlmc/ebin -pa ./deps/erlydtl/ebin -pa ./deps/ets_cache/ebin -pa ./deps/gen_smtp/ebin -pa ./deps/goldrush/ebin -pa ./deps/ibrowse/ebin -pa ./deps/iso8601/ebin -pa ./deps/jaderl/ebin -pa ./deps/jsx/ebin -pa ./deps/lager/ebin -pa ./deps/medici/ebin -pa ./deps/mimetypes/ebin -pa ./deps/mochiweb/ebin -pa ./deps/mysql/ebin -pa ./deps/pmod_transform/ebin -pa ./deps/poolboy/ebin -pa ./deps/proper/ebin -pa ./deps/ranch/ebin -pa ./deps/redo/ebin -pa ./deps/simple_bridge/ebin -pa ./deps/tiny_pq/ebin -pa ./deps/tinymq/ebin -pa ./deps/uuid/ebin -pa /app/ebin -pa deps/aleppo/ebin -pa deps/binpp/ebin -pa deps/boss/ebin -pa deps/boss_db/ebin -pa deps/boss_test/ebin -pa deps/color/ebin -pa deps/cowboy/ebin -pa deps/cowlib/ebin -pa deps/ddb/ebin -pa deps/dh_date/ebin -pa deps/dynamic_compile/ebin -pa deps/epgsql/ebin -pa deps/eredis/ebin -pa deps/erlando/ebin -pa deps/erlmc/ebin -pa deps/erlydtl/ebin -pa deps/ets_cache/ebin -pa deps/gen_smtp/ebin -pa deps/goldrush/ebin -pa deps/ibrowse/ebin -pa deps/iso8601/ebin -pa deps/jaderl/ebin -pa deps/jsx/ebin -pa deps/lager/ebin -pa deps/medici/ebin -pa deps/mimetypes/ebin -pa deps/mochiweb/ebin -pa deps/mysql/ebin -pa deps/pmod_transform/ebin -pa deps/poolboy/ebin -pa deps/proper/ebin -pa deps/ranch/ebin -pa deps/redo/ebin -pa deps/simple_bridge/ebin -pa deps/tiny_pq/ebin -pa deps/tinymq/ebin -pa deps/uuid/ebin -boss developing_app erwish -boot start_sasl -config boss  -s reloader -s lager -s boss -sname erwish -noinput -simple_bridge port $PORT

This shell can actually be generatd by calling ./rebar boss c=start_dev_cmd or ./rebar boss c=start_cmd, but actual difference is existance of -detached flag. AND remember to replace -sname erwish with your own application name.

Finally, keep in mind, each time you update rebar with some dependencies, you must update Procfile.