Initial Log Level Counter

* test needs to be implemented

com.swookiee.runtime.metrics.prometheus.test/src/main/groovy/com/swookiee/runtime/metrics/prometheus/logcounter/LogLevelCounterTest.groovy

@@ -0,0 +1,32 @@
+//package com.swookiee.runtime.metrics.prometheus.logcounter;
+//
+//import static org.junit.Assert.assertEquals;
+//
+//import ch.qos.logback.classic.Level;
+//import ch.qos.logback.classic.spi.ILoggingEvent;
+//import io.prometheus.client.CollectorRegistry;
+//import org.junit.Before;
+//import org.junit.Test;
+//
+//public class LogLevelCounterTest {
+//    def LogLevelCounterAppender appender;
+//    def ILoggingEvent event;
+//    def CollectorRegistry collectorRegistry = [] as CollectorRegistry
+//
+//    @Before
+//    public void setUp() throws Exception {
+//        appender = new LogLevelCounterAppender();
+//        appender.start();
+//    }
+//
+//    @Test
+//    public void metersTraceEvents() throws Exception {
+//        event = [getLevel:{Level.TRACE}] as ILoggingEvent
+//        appender.doAppend(event);
+//        assertEquals(1, getLogLevelCount("trace"));
+//    }
+//
+//    private int getLogLevelCount(String level) {
+//        return appender.counter.("counter", ["level"] as String[],[level] as String[]).intValue();
+//    }
+//}

com.swookiee.runtime.metrics.prometheus/META-INF/MANIFEST.MF

@@ -3,7 +3,14 @@ Bundle-ManifestVersion: 2
 Bundle-Name: Swookiee Runtime prometheus Bundle
 Bundle-SymbolicName: com.swookiee.runtime.metrics.prometheus
 Bundle-Version: 1.0.0.qualifier
-Import-Package: com.fasterxml.jackson.annotation,
+Import-Package: ch.qos.logback.classic,
+ ch.qos.logback.classic.spi,
+ ch.qos.logback.core,
+ ch.qos.logback.core.encoder,
+ ch.qos.logback.core.rolling,
+ ch.qos.logback.core.spi,
+ ch.qos.logback.core.status,
+ com.fasterxml.jackson.annotation,
  com.fasterxml.jackson.databind,
  com.swookiee.runtime.util.configuration,
  io.prometheus.client;version="0.0.9",

com.swookiee.runtime.metrics.prometheus/src/main/java/com/swookiee/runtime/metrics/prometheus/logcounter/LogLevelCounter.java

@@ -0,0 +1,48 @@
+/**
+ * *****************************************************************************
+ * Copyright (c) 2015 Lars Pfannenschmidt and others. All rights reserved. This
+ * program and the accompanying materials are made available under the terms of
+ * the Eclipse Public License v1.0 which accompanies this distribution, and is
+ * available at http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Lars Pfannenschmidt - initial implementation
+ * *****************************************************************************
+ */
+package com.swookiee.runtime.metrics.prometheus.logcounter;
+
+import io.prometheus.client.Collector;
+
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.ServiceRegistration;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Deactivate;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Component
+public class LogLevelCounter {
+    private static final Logger logger = LoggerFactory.getLogger(LogLevelCounter.class);
+    private ServiceRegistration<Collector> registerdCounter;
+    private LogLevelCounterAppender instrumentedAppender;
+    private ch.qos.logback.classic.Logger rootLogger;
+
+    @Activate
+    public void activate(BundleContext bundleContext) {
+        logger.info("Starting Prometheus Log Level Counter!");
+        rootLogger = (ch.qos.logback.classic.Logger) LoggerFactory.getLogger("root");
+        instrumentedAppender = new LogLevelCounterAppender();
+        instrumentedAppender.start();
+        rootLogger.addAppender(instrumentedAppender);
+        registerdCounter = bundleContext.registerService(Collector.class, instrumentedAppender.getCounter(), null);
+    }
+
+    @Deactivate
+    public void deactivate() {
+        instrumentedAppender.stop();
+        rootLogger.detachAppender(instrumentedAppender);
+        registerdCounter.unregister();
+        logger.info("Stopped Prometheus Log Level Counter!");
+    }
+}

com.swookiee.runtime.metrics.prometheus/src/main/java/com/swookiee/runtime/metrics/prometheus/logcounter/LogLevelCounterAppender.java

@@ -0,0 +1,69 @@
+/**
+ * *****************************************************************************
+ * Copyright (c) 2015 Lars Pfannenschmidt and others. All rights reserved. This
+ * program and the accompanying materials are made available under the terms of
+ * the Eclipse Public License v1.0 which accompanies this distribution, and is
+ * available at http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Lars Pfannenschmidt - initial implementation
+ * *****************************************************************************
+ */
+package com.swookiee.runtime.metrics.prometheus.logcounter;
+
+import io.prometheus.client.Counter;
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.UnsynchronizedAppenderBase;
+
+public class LogLevelCounterAppender extends UnsynchronizedAppenderBase<ILoggingEvent> {
+
+    public static final String COUNTER_NAME = "logback_loglevel_total";
+
+    private final Counter counter;
+    private final Counter.Child traceLabel;
+    private final Counter.Child debugLabel;
+    private final Counter.Child infoLabel;
+    private final Counter.Child warnLabel;
+    private final Counter.Child errorLabel;
+
+    public LogLevelCounterAppender() {
+        counter = Counter.build()
+                .name(COUNTER_NAME)
+                .help("Logback log statements at various log levels")
+                .labelNames("level")
+                .register();
+        traceLabel = counter.labels("trace");
+        debugLabel = counter.labels("debug");
+        infoLabel = counter.labels("info");
+        warnLabel = counter.labels("warn");
+        errorLabel = counter.labels("error");
+    }
+
+    @Override
+    protected void append(ILoggingEvent event) {
+        switch (event.getLevel().toInt()) {
+        case Level.TRACE_INT:
+            traceLabel.inc();
+            break;
+        case Level.DEBUG_INT:
+            debugLabel.inc();
+            break;
+        case Level.INFO_INT:
+            infoLabel.inc();
+            break;
+        case Level.WARN_INT:
+            warnLabel.inc();
+            break;
+        case Level.ERROR_INT:
+            errorLabel.inc();
+            break;
+        default:
+            break;
+        }
+    }
+
+    public Counter getCounter() {
+        return counter;
+    }
+}

com.swookiee.runtime.metrics.prometheus/src/main/java/com/swookiee/runtime/metrics/prometheus/servlet/MetricsService.java

@@ -13,22 +13,29 @@
  */
 package com.swookiee.runtime.metrics.prometheus.servlet;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.swookiee.runtime.metrics.prometheus.CollectorRegistryInventory;
 import io.prometheus.client.CollectorRegistry;
 import io.prometheus.client.exporter.common.TextFormat;
-import org.osgi.service.component.annotations.*;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
-import javax.ws.rs.core.MediaType;
-import javax.ws.rs.core.Response;
-import javax.ws.rs.core.UriInfo;
 import java.io.IOException;
 import java.io.StringWriter;
 import java.util.Iterator;
 import java.util.Set;
 
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.core.UriInfo;
+
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Deactivate;
+import org.osgi.service.component.annotations.Reference;
+import org.osgi.service.component.annotations.ReferenceCardinality;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.swookiee.runtime.metrics.prometheus.CollectorRegistryInventory;
+
 @Component
 public class MetricsService implements Metrics {
 
@@ -48,11 +55,11 @@ public void deactivate() {
     }
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY)
-    public void setMetricRegistry(final CollectorRegistryInventory inventory) {
+    public void setMetricRegistry(CollectorRegistryInventory inventory) {
         this.inventory = inventory;
     }
 
-    public void unsetMetricRegistry(final CollectorRegistryInventory inventory) {
+    public void unsetMetricRegistry(CollectorRegistryInventory inventory) {
         this.inventory = null;
     }
 
@@ -85,16 +92,14 @@ public Response plainBundleList() {
 
     @Override
     public Response htmlBundleList(UriInfo uri) {
-        String linkTemplate = "<a href="
-                + uri.getAbsolutePath().toString();
+        String linkTemplate = "<a href=" + uri.getAbsolutePath().toString();
 
-        if (uri.getAbsolutePath().toString().endsWith("/")){
+        if (uri.getAbsolutePath().toString().endsWith("/")) {
             linkTemplate += "%s>%s</a><br />";
         } else {
             linkTemplate += "/%s>%s</a><br />";
         }
 
-
         StringBuilder builder = new StringBuilder();
         builder.append("<html><head></head><body>");
         for (String bundle : inventory.getRegisteredBundles()) {