heroku-buildpack-kong

by heroku

GitHub Readme.md

Heroku Buildpack for Kong

Deploy Kong 0.14 Community Edition as a Heroku app.

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

Usage

Deploy the heroku-kong app to get started.

Custom

While it's possible to use this buildpack directly, you'll be giving up quite a few features of the heroku-kong app:

  • Admin API will not be automatically proxied for secure external access
  • Admin Console via heroku run will require manual setup
  • local development is not preconfigured

Create a new git repo and Heroku app:

APP_NAME=my-kong-gateway # name this something unique for your app
mkdir $APP_NAME
cd $APP_NAME
git init
heroku create $APP_NAME
heroku buildpacks:set https://github.com/heroku/heroku-buildpack-kong.git
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

echo '# Kong Proxy' > README.md
git add README.md

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
  • 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

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.

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.

Pre-release script

This buildpack installs a release phase script to automatically run Kong's database migrations for each deployment.

Apps can define a custom pre-release script which will be automatically invoked before the built-in release phase script.

Simply commit your executable script to the app's repo as bin/prerelease, and then that script will be run for every release. The release will fail if the script exits with non-zero status.

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