prom unit parsing impl

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/metrics/scrape/prometheus/PrometheusEndpointParser.java

@@ -25,19 +25,27 @@ public class PrometheusEndpointParser {
 
     String name;
     String help;
-    Type type = null;
+    Type type;
+    String unit;
     Set<String> allowedNames = new HashSet<>();
     List<Sample> samples = new ArrayList<>();
 
     void registerAndReset() {
       if (!samples.isEmpty()) {
         registered.add(
-            new MetricFamilySamples(name, type, Optional.ofNullable(help).orElse(name), List.copyOf(samples)));
+            new MetricFamilySamples(
+                name,
+                Optional.ofNullable(unit).orElse(""),
+                type,
+                Optional.ofNullable(help).orElse(name),
+                List.copyOf(samples))
+        );
       }
       //resetting state:
       name = null;
       help = null;
       type = null;
+      unit = null;
       allowedNames.clear();
       samples.clear();
     }
@@ -60,6 +68,7 @@ public class PrometheusEndpointParser {
               switch (parts[1]) {
                 case "HELP" -> processHelp(context, parts);
                 case "TYPE" -> processType(context, parts);
+                case "UNIT" -> processUnit(context, parts);
                 default -> { /* probably a comment */ }
               }
             }
@@ -70,6 +79,19 @@ public class PrometheusEndpointParser {
     return context.getRegistered();
   }
 
+  private static void processUnit(ParserContext context, String[] parts) {
+    if (!parts[2].equals(context.name)) {
+      // starting new metric family - need to register (if possible) prev one
+      context.registerAndReset();
+      context.name = parts[2];
+      context.type = DEFAULT_TYPE;
+      context.allowedNames.add(context.name);
+    }
+    if (parts.length == 4) {
+      context.unit = parts[3];
+    }
+  }
+
   private static void processHelp(ParserContext context, String[] parts) {
     if (!parts[2].equals(context.name)) {
       // starting new metric family - need to register (if possible) prev one

kafka-ui-api/src/test/java/com/provectus/kafka/ui/service/metrics/scrape/prometheus/PrometheusEndpointParserTest.java

@@ -47,6 +47,11 @@ class PrometheusEndpointParserTest {
             # TYPE something_untyped untyped
             something_untyped{} -123123
 
+            # TYPE unit_test_seconds counter
+            # UNIT unit_test_seconds seconds
+            # HELP unit_test_seconds Testing that unit parsed properly
+            unit_test_seconds_total 4.20072246e+06
+
             # HELP http_request_duration_seconds A histogram of the request duration.
             # TYPE http_request_duration_seconds histogram
             http_request_duration_seconds_bucket{le="0.05"} 24054
@@ -58,7 +63,7 @@ class PrometheusEndpointParserTest {
             http_request_duration_seconds_sum 53423
             http_request_duration_seconds_count 144320
         """;
-    var parsed = parse(expose.lines());
+    List<MetricFamilySamples> parsed = parse(expose.lines());
     assertThat(parsed).contains(
         new MetricFamilySamples(
             "http_requests_total",
@@ -87,6 +92,13 @@ class PrometheusEndpointParserTest {
             "something_untyped",
             List.of(new Sample("something_untyped", List.of(), List.of(), -123123))
         ),
+        new MetricFamilySamples(
+            "unit_test_seconds",
+            "seconds",
+            Type.COUNTER,
+            "Testing that unit parsed properly",
+            List.of(new Sample("unit_test_seconds_total", List.of(), List.of(), 4.20072246e+06))
+        ),
         new MetricFamilySamples(
             "http_request_duration_seconds",
             Type.HISTOGRAM,