HACK: support custom error handlers for grape instrumentation (ruby-g…

…rape/grape#1496)

Gemfile.lock

@@ -8,13 +8,13 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    activemodel (5.0.1)
-      activesupport (= 5.0.1)
-    activerecord (5.0.1)
-      activemodel (= 5.0.1)
-      activesupport (= 5.0.1)
+    activemodel (5.0.2)
+      activesupport (= 5.0.2)
+    activerecord (5.0.2)
+      activemodel (= 5.0.2)
+      activesupport (= 5.0.2)
       arel (~> 7.0)
-    activesupport (5.0.1)
+    activesupport (5.0.2)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (~> 0.7)
       minitest (~> 5.1)
@@ -24,16 +24,16 @@ GEM
       descendants_tracker (~> 0.0.4)
       ice_nine (~> 0.11.0)
       thread_safe (~> 0.3, >= 0.3.1)
-    builder (3.2.2)
+    builder (3.2.3)
     coercible (1.0.0)
       descendants_tracker (~> 0.0.1)
-    concurrent-ruby (1.0.4)
+    concurrent-ruby (1.0.5)
     descendants_tracker (0.0.4)
       thread_safe (~> 0.3, >= 0.3.1)
-    diff-lcs (1.2.5)
+    diff-lcs (1.3)
     dogstatsd-ruby (2.0.0)
     equalizer (0.0.11)
-    grape (0.19.0)
+    grape (0.19.1)
       activesupport
       builder
       hashie (>= 2.1.0)
@@ -43,8 +43,8 @@ GEM
       rack (>= 1.3.0)
       rack-accept
       virtus (>= 1.0.0)
-    hashie (3.4.6)
-    i18n (0.7.0)
+    hashie (3.5.5)
+    i18n (0.8.1)
     ice_nine (0.11.2)
     minitest (5.10.1)
     multi_json (1.12.1)
@@ -72,8 +72,8 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.5.0)
     rspec-support (3.5.0)
-    sqlite3 (1.3.12)
-    thread_safe (0.3.5)
+    sqlite3 (1.3.13)
+    thread_safe (0.3.6)
     tool (0.2.3)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
@@ -97,4 +97,4 @@ DEPENDENCIES
   sqlite3
 
 BUNDLED WITH
-   1.11.2
+   1.14.5

lib/datadog/notifications/plugins/grape.rb

@@ -1,15 +1,17 @@
 module Datadog::Notifications::Plugins
   class Grape < Base
 
-    attr_reader :metric_name
+    attr_reader :metric_name, :exception_handler
 
     # Options:
     #
     # *<tt>:metric_name</tt> - the metric name, defaults to "grape.request"
+    # *<tt>:exception_handler</tt> - a custom exception handler proc which accepts an exception object and returns a status
     # *<tt>:tags</tt> - additional tags
     def initialize(opts = {})
       super
       @metric_name = opts[:metric_name] || "grape.request"
+      @exception_handler = opts[:exception_handler] || ->_ { 500 }
 
       Datadog::Notifications.subscribe 'endpoint_run.grape' do |reporter, event|
         record reporter, event
@@ -24,14 +26,19 @@ def record(reporter, event)
       route    = endpoint.route
       version  = route.version
       method   = route.request_method
+      status   = endpoint.status
+
+      if payload[:exception_object]
+        status = exception_handler.call(payload[:exception_object])
+      end
 
       path = route.pattern.path.dup
       path.sub!(/\(\.\:format\)$/, '')
       path.sub!(":version/", "") if version
       path.gsub!(/:(\w+)/) {|m| m[1..-1].upcase }
       path.gsub!(/[^\w\/\-]+/, '_')
 
-      tags = self.tags + %W|method:#{method} path:#{path} status:#{endpoint.status}|
+      tags = self.tags + %W|method:#{method} path:#{path} status:#{status}|
       tags.push "version:#{version}" if version
 
       reporter.batch do

lib/datadog/notifications/version.rb

@@ -1,5 +1,5 @@
 module Datadog
   class Notifications
-    VERSION = "0.4.4"
+    VERSION = "0.4.5"
   end
 end

spec/datadog/notifications/plugins/grape_spec.rb

@@ -4,6 +4,8 @@
   include Rack::Test::Methods
 
   let(:app) do
+    unauthorized = Class.new(RuntimeError)
+
     sub_api = Class.new(Grape::API) do
       version 'v1'
       prefix  'api'
@@ -12,10 +14,19 @@
     end
 
     Class.new(Grape::API) do
+
+      rescue_from unauthorized do |e|
+        error!({ message: "unauthorized", error: '401 Unauthorized' }, 401)
+      end
+
       get 'echo/:key1/:key2' do
         "#{params['key1']} #{params['key2']}"
       end
 
+      get '/rescued' do
+        raise unauthorized.new("unauthorized")
+      end
+
       namespace :sub do
         mount sub_api
 
@@ -59,4 +70,21 @@
     ])
   end
 
+  it 'should handle rescued errors' do
+    get '/rescued'
+    expect(last_response.status).to eq(401)
+
+    expect(buffered).to eq([
+      "api.request:1|c|#custom:tag,env:test,host:test.host,more:tags,method:GET,path:/rescued,status:401",
+      "api.request.time:333|ms|#custom:tag,env:test,host:test.host,more:tags,method:GET,path:/rescued,status:401",
+    ])
+  end
+
+  it 'should not report paths on 404s' do
+    get '/sub/missing'
+    expect(last_response.status).to eq(404)
+
+    expect(buffered).to eq([])
+  end
+
 end

spec/spec_helper.rb

@@ -62,5 +62,8 @@ def buffered
   c.tags     = ["custom:tag"]
 
   c.use Datadog::Notifications::Plugins::ActiveRecord
-  c.use Datadog::Notifications::Plugins::Grape, tags: ["more:tags"], metric_name: "api.request"
+  c.use Datadog::Notifications::Plugins::Grape,
+    tags: ["more:tags"],
+    metric_name: "api.request",
+    exception_handler: ->e { e.message.include?("unauthorized") ? 401 : 500 }
 end