```ruby
$stdout.sync = true
$stderr.sync = true

require 'rack'
use Rack::Deflater, if: ->(_, _, _, body) { body.any? && body[0].length > 512 }

unless ENV['NO_PROMETHEUS']
  require 'prometheus/middleware/collector'
  require 'prometheus/middleware/exporter'
  use(Prometheus::Middleware::Collector, { metrics_prefix:'runner'})
  use(Prometheus::Middleware::Exporter)
end

require_relative 'src/externals'
require_relative 'src/rack_dispatcher'
require_relative 'src/runner'
externals = Externals.new
runner = Runner.new(externals)
dispatcher = RackDispatcher.new(runner)
run dispatcher
```

Drop Prometheus metrics_prefix; using label app=runner in PromQL is simpler
user
```ruby
$stdout.sync = true
$stderr.sync = true

require 'rack'
use Rack::Deflater, if: ->(_, _, _, body) { body.any? && body[0].length > 512 }

unless ENV['NO_PROMETHEUS']
  require 'prometheus/middleware/collector'
  require 'prometheus/middleware/exporter'
  use Prometheus::Middleware::Collector
  use Prometheus::Middleware::Exporter
end

require_relative 'src/externals'
require_relative 'src/rack_dispatcher'
require_relative 'src/runner'
externals = Externals.new
runner = Runner.new(externals)
dispatcher = RackDispatcher.new(runner)
run dispatcher
```
assistant