OpenResty for Heroku

This is a Lua rock containing binaries for running OpenResty on Heroku. It's designed to be used in conjunction with the Lua buildpack.

What it does

In addition to a pre compiled openresty, some scripts to start nginx are included. nginx doesn't support passing in port through argument or reading from environment variable so we preprocess the config file.

Anything matching ${{NAME}} is replaced with the environment variable NAME inside of your nginx configuration config. (note: doesn't apply to included files)

The start_nginx.sh script will read in nginx.conf, compile it to nginx.conf.compiled then start nginx. It takes two optional arguments, an alternative path for the config as the first and and an alternative root directory to run the server from. The config must be specified relative to the root.

The daemon off; directive must be added to the config for the entire thing to work.

How to use

Installing the rock

Create a new app with the Lua buildpack.

$ heroku create --buildpack http://github.com/leafo/heroku-buildpack-lua.git

Add to your rockspec dependencies:

dependencies = {
  "https://raw.github.com/leafo/heroku-openresty/master/heroku-openresty-1.2.8.6-1.rockspec"
}

Running Nginx

These directions are for manually running Nginx, if you prefer to use a framework then I recommend checking out: http://leafo.net/lapis.

Create a basic nginx.conf, this is the one from the OpenResty guide (with the addition of daemon off and ${{PORT}}):

worker_processes  1;
error_log logs/error.log;
daemon off;
events {
    worker_connections 1024;
}
http {
    server {
        listen ${{PORT}};
        location / {
            default_type text/html;
            content_by_lua '
                ngx.say("<p>hello, world</p>")
            ';
        }
    }
}

Create a Procfile:

web: start_nginx.sh

Commit everything and push to deploy. Run heroku scale web=1 if nginx doesn't start automatically.

Using PostgreSQL

This build includes the Postgres nginx module, all you need to do is pass in your database configuration.

First add a database if you haven't added one already:

heroku addons:add heroku-postgresql:dev

This will set an environment variable inside of your application that looks something like this:

HEROKU_POSTGRESQL_ROSE_URL="postgres://user:[email protected]/databasename"

The nginx config expects a slightly different format, but no worries the config preprocessor has a filter to convert to the correct format.

Add the database to your config like so: (notice the prefix pg)

http {
    upstream database {
      postgres_server ${{pg HEROKU_POSTGRESQL_ROSE_URL}};
    }
}

That's it, your application can now talk to Postgres through the database upstream.

Version

• OpenResty 1.5.11.1 --with-http_postgres_module