heroku-buildpack-kong

by brandoshmando

GitHub Readme.md

Heroku Buildpack for Kong

Deploy Kong 0.11 Community Edition as a Heroku app.

🌈 This buildpack now deploys genuine Mashape Kong, built from source on Github; patches are no longer required for compatibility with Heroku.

🔬👩‍💻 This software is a community proof-of-concept: MIT license

Usage

Example

Deploy the heroku-kong app to get started.

Custom

Create a new git repo and Heroku app:

mkdir my-kong-app
cd my-kong-app
git init
heroku create $APP_NAME
heroku buildpacks:set https://github.com/heroku/heroku-buildpack-kong
heroku addons:create heroku-postgresql:hobby-dev

Create the file config/kong.conf.etlua based on the sample config file. This is a config template which generates config/kong.conf at runtime.

git add config/kong.conf.etlua
git commit -m '🐒'
git push heroku master

🚀 Check heroku logs and heroku open to verify Kong launches.

Plugins & other Lua source

  • Kong plugins
  • Lua rocks
    • specify in the app's Rockfile
    • each line is {NAME} {VERSION}
  • Other Lua source modules
    • lib/{NAME}.lua or
    • lib/{NAME}/init.lua

Environment variables

  • PORT exposed on the app/dyno

    • set automatically by the Heroku dyno manager
  • <CUSTOM>_PORT if you'd like to specify a custom port per process type for the instance to listen on, (useful for exposing to private spaces network) then you can set an env var the the name of the process prepended to _PORT like so:

    Procfile
    --------
    web: bin/heroku-buildpack-web
    private: bin/heroku-buildpack-web
    
    Env var
    -------
    PRIVATE_PORT=<desired port number here>
    
  • KONG_GIT_URL git repo URL for Kong source

    • example https://github.com/Mashape/kong.git
  • KONG_GIT_COMMITISH git branch/tag/commit for Kong source

    • example master
  • DATABASE_URL

  • KONG_EXPOSE allows you to choose which listener is exposed to the specified port

    • proxy (default), admin, adminssl, proxyssl
  • <CUSTOM>_KONG_EXPOSE allows you to choose which listener is exposed to the specified port per process.

    • If you don't specify this value, the value from KONG_EXPOSE will be used
    • Using the Procfile example above, the env var would look something like:
    Env var
    -------
    PRIVATE_KONG_EXPOSE=<desired value>
    

Using Environment Variables in Plugins

To use env vars within your own code.

  1. Whitelist the variable name for use within Nginx
    • In a custom Nginx config file add env MY_VARIABLE;
    • See: Nginx config (below)
  2. Access the variable in Lua plugins
    • Use os.getenv('MY_VARIABLE') to retrieve the value.

Kong config

To customize your kong.conf, create config/kong.conf.etlua based on the sample config file in your project. By default, this buildpack will use this file as a template for the final kong.conf file. If you need to specify a separate template per process type, simply create config/<process name>-kong.conf.etlua where process name is that of the corresponding process in the Procfile. The latter use case is mostly for private space users.

Nginx config

Kong is an Nginx-based application. To customize the underlying Nginx configuration, commit the file config/nginx.template with contents based on the docs or this included sample.

Testing

This buildpack supports Heroku CI to automate test runs and integrate with deployment workflow.

Tests should follow the Kong plugin testing guide.

App requirements:

  • spec/kong_tests.conf must contain the Kong configuration for running tests

See: sample Heroku Kong app which contains a complete test suite.

Background

The first time this buildpack builds an app, the build time will be significantly longer as Kong and its dependencies are compiled from source. The compiled artifacts are cached to speed up subsequent builds.

We vendor the sources for Lua, LuaRocks, & OpenResty/Nginx and compile them with a writable /app/.heroku prefix. Attempts to bootstrap Kong on Heroku using existing Lua & apt buildpacks failed due to their compile-time prefixes of /usr/local which is read-only in a dyno.

OpenSSL 1.0.2 (required by OpenResty) is also compiled from source.

Modification

This buildpack caches its compilation artifacts from the sources in vendor/. Changes to the sources in vendor/ will be detected and the cache ignored.

If you need to trigger a full rebuild without changing the source, use the Heroku Repo CLI plugin to purge the cache:

heroku repo:purge_cache