add lowecase + testing

Author: SylvainJuge

instrumentation/jmx-metrics/library/src/main/java/io/opentelemetry/instrumentation/jmx/engine/MetricAttributeExtractor.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.instrumentation.jmx.engine;
 
+import java.util.Locale;
 import javax.annotation.Nullable;
 import javax.management.MBeanServerConnection;
 import javax.management.ObjectName;
@@ -46,4 +47,20 @@ static MetricAttributeExtractor fromObjectNameParameter(String parameterKey) {
   static MetricAttributeExtractor fromBeanAttribute(String attributeName) {
     return BeanAttributeExtractor.fromName(attributeName);
   }
+
+  /**
+   * Provides an extractor that will transform provided string value in lower-case
+   *
+   * @param extractor extractor to wrap
+   * @return lower-case extractor
+   */
+  static MetricAttributeExtractor toLowerCase(MetricAttributeExtractor extractor) {
+    return (a, b) -> {
+      String value = extractor.extractValue(a, b);
+      if (value != null) {
+        value = value.toLowerCase(Locale.ROOT);
+      }
+      return value;
+    };
+  }
 }

instrumentation/jmx-metrics/library/src/main/java/io/opentelemetry/instrumentation/jmx/yaml/MetricStructure.java

@@ -136,7 +136,18 @@ private List<MetricAttribute> addMetricAttributes(Map<String, Object> metricAttr
     return list;
   }
 
-  private static MetricAttribute buildMetricAttribute(String key, String target) {
+  // package protected for testing
+  static MetricAttribute buildMetricAttribute(String key, String target) {
+
+    // an optional modifier may wrap the target
+    // - lowercase(param(STRING))
+    boolean lowercase = false;
+    if (target.startsWith("lowercase(")) {
+      lowercase = true;
+      target = target.substring(10, target.lastIndexOf(')'));
+    }
+
+    //
     // The recognized forms of target are:
     //  - param(STRING)
     //  - beanattr(STRING)
@@ -145,24 +156,32 @@ private static MetricAttribute buildMetricAttribute(String key, String target) {
     // or the direct value to use
     int k = target.indexOf(')');
 
+    MetricAttributeExtractor extractor = null;
+
     // Check for one of the cases as above
     if (target.startsWith("param(")) {
       if (k > 0) {
         String jmxAttribute = target.substring(6, k).trim();
-        return new MetricAttribute(
-            key, MetricAttributeExtractor.fromObjectNameParameter(jmxAttribute));
+        extractor = MetricAttributeExtractor.fromObjectNameParameter(jmxAttribute);
       }
     } else if (target.startsWith("beanattr(")) {
       if (k > 0) {
         String jmxAttribute = target.substring(9, k).trim();
-        return new MetricAttribute(key, MetricAttributeExtractor.fromBeanAttribute(jmxAttribute));
+        extractor = MetricAttributeExtractor.fromBeanAttribute(jmxAttribute);
       }
     } else if (target.startsWith("const(")) {
       if (k > 0) {
         String constantValue = target.substring(6, k).trim();
-        return new MetricAttribute(key, MetricAttributeExtractor.fromConstant(constantValue));
+        extractor = MetricAttributeExtractor.fromConstant(constantValue);
       }
     }
+    if (extractor != null) {
+      if (lowercase) {
+        extractor = MetricAttributeExtractor.toLowerCase(extractor);
+      }
+
+      return new MetricAttribute(key, extractor);
+    }
 
     String msg = "Invalid metric attribute specification for '" + key + "': " + target;
     throw new IllegalArgumentException(msg);

instrumentation/jmx-metrics/library/src/test/java/io/opentelemetry/instrumentation/jmx/engine/RuleParserTest.java

@@ -451,6 +451,39 @@ void testStateMetricConf() throws Exception {
             });
   }
 
+  private static final String CONF10 =
+      "---                                   # keep stupid spotlessJava at bay\n"
+          + "rules:\n"
+          + "  - bean: my-test:type=10_Hello\n"
+          + "    mapping:\n"
+          + "      jmxAttribute:\n"
+          + "        type: counter\n"
+          + "        metric: my_metric\n"
+          + "        metricAttribute:\n"
+          + "          to_lower_const: lowercase(const(Hello))\n"
+          + "          to_lower_attribute: lowercase(beanattr(beanAttribute))\n"
+          + "          to_lower_param: lowercase(param(type))\n";
+
+  @Test
+  void attributeValueLowercase() {
+
+    JmxConfig config = parseConf(CONF10);
+
+    List<JmxRule> rules = config.getRules();
+    assertThat(rules).hasSize(1);
+    JmxRule jmxRule = rules.get(0);
+
+    assertThat(jmxRule.getBean()).isEqualTo("my-test:type=10_Hello");
+    Metric metric = jmxRule.getMapping().get("jmxAttribute");
+    assertThat(metric.getMetricType()).isEqualTo(MetricInfo.Type.COUNTER);
+    assertThat(metric.getMetric()).isEqualTo("my_metric");
+    assertThat(metric.getMetricAttribute())
+        .hasSize(3)
+        .containsEntry("to_lower_const", "lowercase(const(Hello))")
+        .containsEntry("to_lower_attribute", "lowercase(beanattr(beanAttribute))")
+        .containsEntry("to_lower_param", "lowercase(param(type))");
+  }
+
   @Test
   void testEmptyConf() {
     JmxConfig config = parseConf(EMPTY_CONF);

instrumentation/jmx-metrics/library/src/test/java/io/opentelemetry/instrumentation/jmx/yaml/MetricStructureTest.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.instrumentation.jmx.yaml;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import io.opentelemetry.instrumentation.jmx.engine.MetricAttribute;
+import javax.management.MBeanAttributeInfo;
+import javax.management.MBeanInfo;
+import javax.management.MBeanServerConnection;
+import javax.management.ObjectName;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+public class MetricStructureTest {
+
+  @ParameterizedTest
+  @CsvSource({"const(Hello),Hello", "lowercase(const(Hello)),hello"})
+  void metricAttribute_constant(String target, String expectedValue) {
+    MetricAttribute ma = MetricStructure.buildMetricAttribute("name", target);
+    assertThat(ma.getAttributeName()).isEqualTo("name");
+    assertThat(ma.isStateAttribute()).isFalse();
+    assertThat(ma.acquireAttributeValue(null, null)).isEqualTo(expectedValue);
+  }
+
+  @ParameterizedTest
+  @CsvSource({
+    "beanattr(beanAttribute),Hello,Hello",
+    "lowercase(beanattr(beanAttribute)),Hello,hello",
+  })
+  void metricAttribute_beanAttribute(String target, String value, String expectedValue)
+      throws Exception {
+    MetricAttribute ma = MetricStructure.buildMetricAttribute("name", target);
+    assertThat(ma.getAttributeName()).isEqualTo("name");
+    assertThat(ma.isStateAttribute()).isFalse();
+
+    ObjectName objectName = new ObjectName("test:name=_beanAttribute");
+    MBeanServerConnection mockConnection = mock(MBeanServerConnection.class);
+
+    MBeanInfo mockBeanInfo = mock(MBeanInfo.class);
+    when(mockBeanInfo.getAttributes())
+        .thenReturn(
+            new MBeanAttributeInfo[] {
+              new MBeanAttributeInfo("beanAttribute", "java.lang.String", "", true, false, false)
+            });
+    when(mockConnection.getMBeanInfo(objectName)).thenReturn(mockBeanInfo);
+    when(mockConnection.getAttribute(objectName, "beanAttribute")).thenReturn(value);
+
+    assertThat(ma.acquireAttributeValue(mockConnection, objectName)).isEqualTo(expectedValue);
+  }
+
+  @ParameterizedTest
+  @CsvSource({
+    "param(name),Hello,Hello",
+    "lowercase(param(name)),Hello,hello",
+  })
+  void metricAttribute_beanParam(String target, String value, String expectedValue)
+      throws Exception {
+    MetricAttribute ma = MetricStructure.buildMetricAttribute("name", target);
+    assertThat(ma.getAttributeName()).isEqualTo("name");
+    assertThat(ma.isStateAttribute()).isFalse();
+
+    ObjectName objectName = new ObjectName("test:name=" + value);
+    MBeanServerConnection mockConnection = mock(MBeanServerConnection.class);
+
+    assertThat(ma.acquireAttributeValue(mockConnection, objectName)).isEqualTo(expectedValue);
+  }
+}