Redis support for sentry-ruby

Patches a Redis client to capture breadcrumb and span data when calls
are made to Redis.

sentry-ruby/Gemfile

@@ -9,6 +9,7 @@ gem "rake", "~> 12.0"
 gem "rspec", "~> 3.0"
 gem "rspec-retry"
 gem "webmock"
+gem "fakeredis"
 gem "timecop"
 gem 'simplecov'
 gem "simplecov-cobertura", "~> 1.4"

sentry-ruby/lib/sentry-ruby.rb

@@ -344,3 +344,4 @@ def utc_now
 
 # patches
 require "sentry/net/http"
+require "sentry/redis/client"

sentry-ruby/lib/sentry/redis/client.rb

@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+module Sentry
+  # @api private
+  module Redis
+    module Client
+      OP_NAME = "redis"
+
+      def logging(commands, &block)
+        start_sentry_span.then do |sentry_span|
+          super.tap do
+            record_sentry_breadcrumb(commands)
+            record_sentry_span(commands, sentry_span)
+          end
+        end
+      end
+
+      private
+
+      def start_sentry_span
+        return unless Sentry.initialized? && transaction = Sentry.get_current_scope.get_transaction
+        return if transaction.sampled == false
+
+        transaction.start_child(op: OP_NAME, start_timestamp: Sentry.utc_now.to_f)
+      end
+
+      def record_sentry_breadcrumb(description)
+        return unless Sentry.initialized? && Sentry.configuration.breadcrumbs_logger.include?(:redis_logger)
+
+        Sentry.add_breadcrumb(
+          Sentry::Breadcrumb.new(
+            level: :info,
+            category: OP_NAME,
+            type: :info,
+            data: {
+              command: commands.first.first,
+              key: commands.first.second
+            }
+          )
+        )
+      end
+
+      def record_sentry_span(commands, sentry_span)
+        return unless Sentry.initialized? && sentry_span
+
+        sentry_span.set_description(generate_description(commands))
+        sentry_span.set_data(:server, server_description)
+        sentry_span.set_timestamp(Sentry.utc_now.to_f)
+      end
+
+      def generate_description(commands)
+        commands.first.take(2).join(" ")
+      end
+
+      def server_description
+        "#{host}:#{port}/#{db}"
+      end
+    end
+  end
+end
+
+Sentry.register_patch do
+  patch = Sentry::Redis
+  Redis::Client.prepend(Sentry::Redis::Client) unless Redis::Client.ancestors.include?(patch)
+end

sentry-ruby/spec/sentry/redis/client_spec.rb

@@ -0,0 +1,45 @@
+require "spec_helper"
+require "fakeredis"
+
+RSpec.describe Sentry::Redis::Client do
+  let(:string_io) { StringIO.new }
+  let(:logger) do
+    ::Logger.new(string_io)
+  end
+  let(:redis) do
+    Redis.new
+  end
+
+  context "with tracing enabled" do
+    before do
+      perform_basic_setup do |config|
+        config.traces_sample_rate = 1.0
+        config.transport.transport_class = Sentry::HTTPTransport
+        config.logger = logger
+        # the dsn needs to have a real host so we can make a real connection before sending a failed request
+        config.dsn = 'http://foobarbaz@o447951.ingest.sentry.io/5434472'
+      end
+    end
+
+    context "with config.send_default_pii = true" do
+      before do
+        Sentry.configuration.send_default_pii = true
+      end
+
+      it "records the request's span with query string" do
+        transaction = Sentry.start_transaction
+        Sentry.get_current_scope.set_span(transaction)
+
+        redis.set("key", "value")
+
+        request_span = transaction.span_recorder.spans.last
+        expect(request_span.op).to eq("redis")
+        expect(request_span.start_timestamp).not_to be_nil
+        expect(request_span.timestamp).not_to be_nil
+        expect(request_span.start_timestamp).not_to eq(request_span.timestamp)
+        expect(request_span.description).to eq("set key")
+        expect(request_span.data).to eq({ server: "127.0.0.1:6379/0" })
+      end
+    end
+  end
+end