Fix custom_labels in SidekiqProcessCollector

Author: mbarany

lib/prometheus_exporter/server/sidekiq_process_collector.rb

@@ -24,9 +24,9 @@ def metrics
       SIDEKIQ_PROCESS_GAUGES.each_key { |name| gauges[name]&.reset! }
 
       sidekiq_metrics.map do |metric|
-        labels = metric.fetch("labels", {})
+        labels = metric.fetch("custom_labels", {}).merge(metric["process"]["labels"])
         SIDEKIQ_PROCESS_GAUGES.map do |name, help|
-          if (value = metric[name])
+          if (value = metric["process"][name])
             gauge =
               gauges[name] ||= PrometheusExporter::Metric::Gauge.new(
                 "sidekiq_process_#{name}",
@@ -41,7 +41,7 @@ def metrics
     end
 
     def collect(object)
-      @sidekiq_metrics << object["process"]
+      @sidekiq_metrics << object
     end
   end
 end

test/server/sidekiq_process_collector_test.rb

@@ -77,4 +77,55 @@ def test_only_fresh_metrics_are_collected
       assert_equal expected, metrics.map(&:metric_text)
     end
   end
+
+  def test_collecting_metrics_with_custom_labels
+    collector.collect(
+      "custom_labels" => { "service" => "payments", "env" => "prod" },
+      "process" => {
+        "busy" => 3,
+        "concurrency" => 10,
+        "labels" => {
+          "labels" => "lab_a",
+          "queues" => "critical,default",
+          "quiet" => "false",
+          "tag" => "main",
+          "hostname" => "sidekiq-host",
+          "identity" => "sidekiq-host:1",
+        },
+      },
+    )
+
+    metrics = collector.metrics
+    expected = [
+      'sidekiq_process_busy{service="payments",env="prod",labels="lab_a",queues="critical,default",quiet="false",tag="main",hostname="sidekiq-host",identity="sidekiq-host:1"} 3',
+      'sidekiq_process_concurrency{service="payments",env="prod",labels="lab_a",queues="critical,default",quiet="false",tag="main",hostname="sidekiq-host",identity="sidekiq-host:1"} 10',
+    ]
+    assert_equal expected, metrics.map(&:metric_text)
+  end
+
+  def test_custom_labels_overridden_by_process_labels
+    collector.collect(
+      "custom_labels" => { "service" => "billing", "tag" => "override" },
+      "process" => {
+        "busy" => 4,
+        "concurrency" => 8,
+        "labels" => {
+          "labels" => "lab_x",
+          "queues" => "default",
+          "quiet" => "true",
+          "tag" => "real_tag",
+          "hostname" => "host-1",
+          "identity" => "host-1:2",
+        },
+      },
+    )
+
+    # tag should be from process labels (real_tag) not custom_labels (override)
+    metrics = collector.metrics
+    expected = [
+      'sidekiq_process_busy{service="billing",tag="real_tag",labels="lab_x",queues="default",quiet="true",hostname="host-1",identity="host-1:2"} 4',
+      'sidekiq_process_concurrency{service="billing",tag="real_tag",labels="lab_x",queues="default",quiet="true",hostname="host-1",identity="host-1:2"} 8',
+    ]
+    assert_equal expected, metrics.map(&:metric_text)
+  end
 end