Merge d2aab1a into 8b20201

lib/prometheus/middleware/collector.rb

@@ -91,6 +91,7 @@ def strip_ids_from_path(path)
         path
           .gsub(%r{/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}(/|$)}, '/:uuid\\1')
           .gsub(%r{/\d+(/|$)}, '/:id\\1')
+          .gsub(%r{/\w+--[0-9a-f]+(/|$)}, '/:signed_id\\1')
       end
     end
   end

spec/prometheus/middleware/collector_spec.rb

@@ -95,6 +95,20 @@
     expect(registry.get(metric).get(labels: labels)).to include("0.1" => 0, "0.5" => 1)
   end
 
+  it 'normalizes paths containing signed_ids by default' do
+    expect(Benchmark).to receive(:realtime).and_yield.and_return(0.3)
+
+    get '/foo/eyJfcmFpbHMiOnsibWVzc2FnZSI6--a419915169c2dc3419/bars'
+
+    metric = :http_server_requests_total
+    labels = { method: 'get', path: '/foo/:signed_id/bars', code: '200' }
+    expect(registry.get(metric).get(labels: labels)).to eql(1.0)
+
+    metric = :http_server_request_duration_seconds
+    labels = { method: 'get', path: '/foo/:signed_id/bars' }
+    expect(registry.get(metric).get(labels: labels)).to include("0.1" => 0, "0.5" => 1)
+  end
+
   context 'when the app raises an exception' do
     let(:original_app) do
       lambda do |env|