Grape

AppSignal for RubyThis feature requires version 1.1 or higher.

Installation

A Grape application requires a few manual steps to get working.

  1. Create a config/appsignal.yml configuration file or configure it with environment variables. For more information see the Ruby configuration page.
  • Make sure AppSignal is required, require "appsignal".
  • Require the Grape integration, require "appsignal/integrations/grape".
  • Start AppSignal, Appsignal.start.

A Grape config.ru file looks something like this:

ruby
# config.ru require File.expand_path("../config/environment", __FILE__) require_relative "./api.rb" Appsignal.config = Appsignal::Config.new( File.expand_path("../", __FILE__), # The root of your app ENV["RACK_ENV"] # The environment of your app (development/production) ) Appsignal.start_logger Appsignal.start run Acme::App

An example of a Grape api.rb file:

ruby
# api.rb # require these two files require "appsignal" require "appsignal/integrations/grape" module Acme class API < Grape::API insert_before Grape::Middleware::Error, Appsignal::Grape::Middleware # Include this middleware prefix "api" format :json get "/" do { :message => "Hello world!" } end end end

insert_before was introduced in Grape 0.19. If you use an earlier version use this approach:

ruby
use Appsignal::Grape::Middleware

After these steps, start your Grape application and wait for data to arrive in AppSignal.

Grape on Rails

Grape is often used in combination with Ruby on Rails as a mounted application. To make sure performance and error metrics from both Grape and Rails are captured we recommend the following configuration:

  1. Install AppSignal for Rails as described in the documentation.
  2. Add the Appsignal::Grape::Middleware to each grape-root file for every API, for example app/controllers/api/v1/root.rb.
ruby
# root.rb require "appsignal/integrations/grape" module Acme class API < Grape::API use Appsignal::Grape::Middleware # Include this middleware prefix "api" format :json get "/" do { :message => "Hello world!" } end end end

Ignoring errors

Note: Ignoring errors from Grape apps this way is supported since AppSignal Ruby gem version 2.10.5.

To ignore a specific Grape error set the grape.skip_appsignal_error flag in the request environment. This will tell AppSignal to ignore the error that occurs during the request. This allows you to stop reporting of errors to AppSignal.

Only ignore errors like this if you need to ignore errors from a Grape app using code. See the ignore_errors option to ignore it for the entire app. If you don't want to be notified about an error, see our notification settings.

ruby
get "/" do env["grape.skip_appsignal_error"] = true # Add this line to an endpoint or callback raise "uh oh" # Example error, don't copy this end

Note that if an error is rescued in the app itself using rescue_from AppSignal will not receive and track the error. The error will need to be manually set on the AppSignal transaction.

ruby
class Api < ::Grape::API insert_before Grape::Middleware::Error, Appsignal::Grape::Middleware format :json base.rescue_from :all do |error| Appsignal.set_error(error) error!({ :foo => "bar" }.to_json, 500) end end

Example app

We have an example application in our examples repository on GitHub. The example shows how to set up AppSignal with Grape.