Add 'additional_tags' list to the configuration: ref #108

This allows a user to define additional tag at the 'include' level (with alias using the '' notation).

src/main/java/org/datadog/jmxfetch/Filter.java

@@ -11,6 +11,7 @@ class Filter {
     Pattern domainRegex;
     ArrayList<Pattern> beanRegexes = null;
     ArrayList<String> excludeTags = null;
+    HashMap<String, String> additionalTags = null;
 
     /**
      * A simple class to manipulate include/exclude filter elements more easily
@@ -121,6 +122,20 @@ public ArrayList<String> getExcludeTags() {
         return this.excludeTags;
     }
 
+    public HashMap<String, String> getAdditionalTags() {
+        // Return additional tags
+
+        if (this.additionalTags == null) {
+            if (filter.get("additional_tags") == null){
+                this.additionalTags = new HashMap<String, String>();
+            } else {
+                this.additionalTags = (HashMap<String, String>)filter.get("additional_tags");
+            }
+        }
+
+        return this.additionalTags;
+    }
+
     public String getDomain() {
         return (String) filter.get("domain");
     }

src/main/java/org/datadog/jmxfetch/JMXAttribute.java

@@ -29,7 +29,8 @@ public abstract class JMXAttribute {
     protected static final String ALIAS = "alias";
     protected static final String METRIC_TYPE = "metric_type";
     private final static Logger LOGGER = Logger.getLogger(JMXAttribute.class.getName());
-    private static final List<String> EXCLUDED_BEAN_PARAMS = Arrays.asList("domain", "domain_regex", "bean_name", "bean", "bean_regex", "attribute", "exclude_tags");
+    private static final List<String> EXCLUDED_BEAN_PARAMS = Arrays.asList("domain", "domain_regex", "bean_name", "bean",
+                                                                           "bean_regex", "attribute", "exclude_tags", "additional_tags");
     private static final String FIRST_CAP_PATTERN = "(.)([A-Z][a-z]+)";
     private static final String ALL_CAP_PATTERN = "([a-z0-9])([A-Z])";
     private static final String METRIC_REPLACEMENT = "([^a-zA-Z0-9_.]+)|(^[^a-zA-Z]+)";
@@ -91,6 +92,19 @@ private void applyTagsBlackList() {
         }
     }
 
+    /**
+     * Add alias tag from the 'tag_alias' configuration list
+     */
+    private void addAdditionalTags() {
+        Filter include = this.matchingConf.getInclude();
+        if (include != null) {
+
+            for (Map.Entry<String, String> tag : include.getAdditionalTags().entrySet()) {
+                this.defaultTagsList.add(tag.getKey() + ":" + this.replaceByAlias(tag.getValue()));
+            }
+        }
+    }
+
     public static HashMap<String, String> getBeanParametersHash(String beanParametersString) {
         String[] beanParameters = beanParametersString.split(",");
         HashMap<String, String> beanParamsMap = new HashMap<String, String>(beanParameters.length);
@@ -368,8 +382,11 @@ public Configuration getMatchingConf() {
     public void setMatchingConf(Configuration matchingConf) {
         this.matchingConf = matchingConf;
 
-        // Now that we have the matchingConf, we can filter out excluded tags
-        applyTagsBlackList();
+        // Now that we have the matchingConf we can:
+        // - add additional tags
+        this.addAdditionalTags();
+        // - filter out excluded tags
+        this.applyTagsBlackList();
     }
 
     MBeanAttributeInfo getAttribute() {
@@ -454,12 +471,7 @@ private String getCassandraAlias() {
      *   returns a metric name `my.metric.bar.toto`
      */
     private String getUserAlias(LinkedHashMap<String, LinkedHashMap<String, String>> attribute, String fullAttributeName){
-        String alias = attribute.get(fullAttributeName).get(ALIAS);
-
-        // Bean parameters
-        for (Map.Entry<String, String> param : beanParameters.entrySet()) {
-            alias = alias.replace("$" + param.getKey(), param.getValue());
-        }
+        String alias = this.replaceByAlias(attribute.get(fullAttributeName).get(ALIAS));
 
         // Attribute & domain
         alias = alias.replace("$attribute", fullAttributeName);
@@ -468,6 +480,14 @@ private String getUserAlias(LinkedHashMap<String, LinkedHashMap<String, String>>
         return alias;
     }
 
+    private String replaceByAlias(String alias){
+        // Bean parameters
+        for (Map.Entry<String, String> param : beanParameters.entrySet()) {
+            alias = alias.replace("$" + param.getKey(), param.getValue());
+        }
+        return alias;
+    }
+
     /**
      * Overload `getAlias` method.
      *

src/test/java/org/datadog/jmxfetch/TestApp.java

@@ -391,6 +391,37 @@ public void testExcludeTags() throws Exception {
         assertMetric("test1.histogram", 424242, commonTags, 2, "histogram");
     }
 
+    @Test
+    public void testAdditionalTags() throws Exception {
+        // We expose a few metrics through JMX
+        SimpleTestJavaApp testApp = new SimpleTestJavaApp();
+        registerMBean(testApp, "org.datadog.jmxfetch.test:type=SimpleTestJavaApp,name=testName");
+
+        // We do a first collection
+        initApplication("jmx_additional_tags.yml");
+        run();
+        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+
+        // We test for the presence and the value of the metrics we want to collect.
+        // Tags "type", "newTag" and "env" should be excluded
+        List<String> commonTags = Arrays.asList(
+            "instance:jmx_test_instance",
+            "jmx_domain:org.datadog.jmxfetch.test",
+            "type:SimpleTestJavaApp",
+            "name:testName",
+            "simple:SimpleTestJavaApp",
+            "raw_value:value",
+            "unknown_tag:$does-not-exist",
+            "multiple:SimpleTestJavaApp-testName");
+
+        // 15 = 13 metrics from java.lang + the 2 collected (gauge and histogram)
+        assertEquals(15, metrics.size());
+
+        // There should only left 2 tags per metric
+        assertMetric("test1.gauge", 1000.0, commonTags, 8, "gauge");
+        assertMetric("test1.histogram", 424242, commonTags, 8, "histogram");
+    }
+
     /**
      * FIXME: Split this test in multiple sub-tests.
      */

src/test/resources/jmx_additional_tags.yml

@@ -0,0 +1,20 @@
+init_config:
+
+instances:
+    -   process_name_regex: .*surefire.*
+        name: jmx_test_instance
+        conf:
+            - include:
+               domain: org.datadog.jmxfetch.test
+               additional_tags:
+                    simple: $type
+                    raw_value: value
+                    unknown_tag: $does-not-exist
+                    multiple: $type-$name
+               attribute:
+                    ShouldBe1000:
+                        metric_type: gauge
+                        alias: test1.gauge
+                    Int424242:
+                        metric_type: histogram
+                        alias: test1.histogram