Forcing nginx into submission (aka running nginx using dynamically compiled config files)

run.rb

require 'rubygems'
require 'erb'

# Nginx needs its config files to contain absolute paths, so
# we need to compile them to set the correct paths.
def expand(filename)
  full_path = File.expand_path(File.dirname(__FILE__))  # "~/Users/david/poetry/sslqsquire/canary"

  File.join(full_path, filename)
end

def compile(filename)
  unless filename.start_with? "/"
    filename = expand(filename)
  end

  contents = File.read(filename)
  ERB.new(contents).result(binding)
end

def indent(content)
  content.split("\n").map{|s| "  #{s}"}.join("\n")
end

def block(name)
  stdout = $stdout
  $stdout = StringIO.new
  output = ""

  begin
    output << yield.to_s
  ensure
    output = $stdout.string + output
    $stdout = stdout
  end

  "#{name} {\n" +
  "#{indent(output)}\n" +
  "}\n"
end


def render_site(path)
  block "http" do
    block "server" do
      puts "root " + expand('nginx/webroot') + ";"

      compile(path)
    end
  end
end

config_file = expand("tmp/nginx.conf")

# Generate config file
File.open config_file, "w" do |conf|
  conf.puts "# Generated at #{Time.now}"

  # Compile the main config file
  conf << compile("nginx/nginx.conf.erb")

  # Compile the different sites
  Dir.glob(expand("sites") + "/*.erb") do |erb_file|
    conf << "# #{erb_file}\n"
    conf << render_site(erb_file)
    conf << "\n\n"
  end
end

`nginx -c #{config_file}`