Merge pull request #62 from erikvanoosten/fix-prometheus-format

Remove trailing comma from labels in prometheus encoding
zio · Jan 10, 2024 · 5396527 · 5396527
2 parents f6adf5e + 794b3f9
commit 5396527
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Showing 2 changed files with 9 additions and 8 deletions.
diff --git a/prometheus/src/main/scala/zio/metrics/connectors/prometheus/PrometheusEncoder.scala b/prometheus/src/main/scala/zio/metrics/connectors/prometheus/PrometheusEncoder.scala
@@ -43,7 +43,8 @@ case object PrometheusEncoder {
         else
           allLabels
             .foldLeft(new StringBuilder(256).append("{")) { case (sb, l) =>
-              sb.append(l.key).append("=\"").append(l.value).append("\",")
+              if (sb.size > 1) sb.append(",")
+              sb.append(l.key).append("=\"").append(l.value).append("\"")
             }
             .append("}")
       ).result()

diff --git a/prometheus/src/test/scala/zio/metrics/connectors/prometheus/PrometheusEncoderSpec.scala b/prometheus/src/test/scala/zio/metrics/connectors/prometheus/PrometheusEncoderSpec.scala
@@ -25,20 +25,20 @@ object PrometheusEncoderSpec extends ZIOSpecDefault with Generators {
         Chunk(
           "# TYPE jvm_memory_pool_collection_max_bytes gauge",
           "#HELP jvm_memory_pool_collection_max_bytes",
-          "jvm_memory_pool_collection_max_bytes{pool=\"Metaspace\",} 0.0 1681853772729",
+          "jvm_memory_pool_collection_max_bytes{pool=\"Metaspace\"} 0.0 1681853772729",
         ),
         Chunk(
           "# TYPE jvm_memory_pool_collection_max_bytes gauge",
           "#HELP jvm_memory_pool_collection_max_bytes",
-          "jvm_memory_pool_collection_max_bytes{pool=\"G1 Eden Space\",} -1.0 1681853772729",
+          "jvm_memory_pool_collection_max_bytes{pool=\"G1 Eden Space\"} -1.0 1681853772729",
         ),
       )
       val groupedMetric = Chunk(
         Chunk(
           "# TYPE jvm_memory_pool_collection_max_bytes gauge",
           "#HELP jvm_memory_pool_collection_max_bytes",
-          "jvm_memory_pool_collection_max_bytes{pool=\"Metaspace\",} 0.0 1681853772729",
-          "jvm_memory_pool_collection_max_bytes{pool=\"G1 Eden Space\",} -1.0 1681853772729",
+          "jvm_memory_pool_collection_max_bytes{pool=\"Metaspace\"} 0.0 1681853772729",
+          "jvm_memory_pool_collection_max_bytes{pool=\"G1 Eden Space\"} -1.0 1681853772729",
         ),
       )
       assertTrue(groupMetricByType(encodedMetric) == groupedMetric)
@@ -48,12 +48,12 @@ object PrometheusEncoderSpec extends ZIOSpecDefault with Generators {
         Chunk(
           "# TYPE jvm_memory_pool_collection_max_bytes gauge",
           "#HELP jvm_memory_pool_collection_max_bytes",
-          "jvm_memory_pool_collection_max_bytes{pool=\"G1 Eden Space\",} -1.0 1681853772729",
+          "jvm_memory_pool_collection_max_bytes{pool=\"G1 Eden Space\"} -1.0 1681853772729",
         ),
         Chunk(
           "# TYPE jvm_memory_pool_collection_used_bytes gauge",
           "#HELP jvm_memory_pool_collection_used_bytes",
-          "TYPE jvm_memory_pool_collection_used_bytes{pool=\"Metaspace\",} 0.0 1681853772729",
+          "TYPE jvm_memory_pool_collection_used_bytes{pool=\"Metaspace\"} 0.0 1681853772729",
         ),
       )
       assertTrue(groupMetricByType(encodedMetric) == encodedMetric)
@@ -66,7 +66,7 @@ object PrometheusEncoderSpec extends ZIOSpecDefault with Generators {
   private def labelString(key: MetricKey.Untyped, extra: (String, String)*) = {
     val tags = key.tags ++ extra.map(x => MetricLabel(x._1, x._2)).toSet
     if (tags.isEmpty) ""
-    else tags.toList.map(l => s"""${l.key}="${l.value}",""").mkString("{", "", "}")
+    else tags.toList.map(l => s"""${l.key}="${l.value}"""").mkString("{", ",", "}")
   }
 
   private val encodeCounter = test("Encode a Counter")(check(genCounter) { case (pair, state) =>