RequestHeaderLogger

RequestHeaderLogger Allows you to tag logs with RequestHeader flags

In micro-service architecture it is very important to be able to corroborate logs from different services for a specific request. The correlation must include both services connected synchronously or asynchronously.

For this issue the X-Request-Id HTTP header was introduced. In Rails the ActionDispatch::RequestId middleware helps create a unique ID for each request if not already defined by the X-Request-Id header. In addition, RequestHeaderMiddleware will allow you to share the same 'X-Request-Id' for multiple requests and multiple services.

Unfortunately, Using RequestHeaderMiddleware and ActionDispatch::RequestId do not solve the Issues completely. RequestHeaderMiddleware will share the X-Request-Id only with synchronous requests.

The gem can be used to share RequestHeader store items the asynchronous services (Delayed Jobs). The default is the while listed item is X-Request-Id. However, It is possible to extend the whilelist with more items.

So how does it work with Rails.

Add this line to your application's Gemfile after the delayed job and message_queue gems:

gem 'request_headers_logger'

And then execute:

$ bundle

That's it now Delayed job logs should show the X-Request-Id from the http request.

RequestHeadersLogger.configure do |config|
  config[:logger_format] = 'json'         # Options [text json] default: text
  config[:tag_format] = 'key_val'         # Options: [val key_val] default: val
end

Per default the delayed job plug in applies a whitelist to only filter X-Request-Id header from the store. To white list new flags, you can do the following.

 RequestHeadersLogger.whitelist << "customer-id".to_sym