Add a prometheus exporter

Change-Id: I2989d87c2a83eed31c6617694bdcb78bf9b38553
diff --git a/apps/openstacktelemetry/app/BUCK b/apps/openstacktelemetry/app/BUCK
index 4cc3d98..0d8faa4 100644
--- a/apps/openstacktelemetry/app/BUCK
+++ b/apps/openstacktelemetry/app/BUCK
@@ -15,6 +15,18 @@
     '//apps/openstacktelemetry/api:onos-apps-openstacktelemetry-api',
     '//lib:kafka-clients',
     '//lib:influxdb-java',
+    '//lib:simpleclient',
+    '//lib:simpleclient_common',
+    '//lib:simpleclient_hotspot',
+    '//lib:simpleclient_servlet',
+    '//lib:jetty-http',
+    '//lib:jetty-servlet',
+    '//lib:jetty-server',
+    '//lib:jetty-security',
+    '//lib:jetty-websocket',
+    '//lib:jetty-util',
+    '//lib:jetty-io',
+    '//lib:servlet-api',
     '//lib:protobuf-java-3.2.0',
     '//lib:GRPC_1.3',
     '//incubator/grpc-dependencies:grpc-core-repkg-' + GRPC_VER,
diff --git a/apps/openstacktelemetry/app/BUILD b/apps/openstacktelemetry/app/BUILD
index c3f3b36..06b9f73 100644
--- a/apps/openstacktelemetry/app/BUILD
+++ b/apps/openstacktelemetry/app/BUILD
@@ -2,6 +2,16 @@
     "@kafka_clients//jar",
     "@jersey_client//jar",
     "@influxdb_java//jar",
+    "@simpleclient//jar",
+    "@simpleclient_common//jar",
+    "@simpleclient_hotspot//jar",
+    "@simpleclient_servlet//jar",
+    "@jetty_servlet//jar",
+    "@jetty_http//jar",
+    "@jetty_server//jar",
+    "@jetty_util//jar",
+    "@jetty_websocket//jar",
+    "@servlet_api//jar",
     "@io_grpc_grpc_java//core",
     "@io_grpc_grpc_java//protobuf-lite",
     "//core/store/serializers:onos-core-serializers",
diff --git a/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/config/DefaultPrometheusTelemetryConfig.java b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/config/DefaultPrometheusTelemetryConfig.java
new file mode 100644
index 0000000..b22f053
--- /dev/null
+++ b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/config/DefaultPrometheusTelemetryConfig.java
@@ -0,0 +1,131 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.openstacktelemetry.config;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Maps;
+import org.onosproject.openstacktelemetry.api.config.PrometheusTelemetryConfig;
+import org.onosproject.openstacktelemetry.api.config.TelemetryConfig;
+
+import java.util.Map;
+import java.util.Objects;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * A configuration file contains Prometheus telemetry parameters.
+ */
+public final class DefaultPrometheusTelemetryConfig implements PrometheusTelemetryConfig {
+
+    private final String address;
+    private final int port;
+    private final Map<String, Object> configMap;
+
+    private DefaultPrometheusTelemetryConfig(String address,
+                                             int port,
+                                             Map<String, Object> configMap) {
+        this.address = address;
+        this.port = port;
+        this.configMap = configMap;
+    }
+
+    @Override
+    public String address() {
+        return address;
+    }
+
+    @Override
+    public int port() {
+        return port;
+    }
+
+    @Override
+    public Map<String, Object> configMap() {
+        if (configMap != null) {
+            return ImmutableMap.copyOf(configMap);
+        } else {
+            return Maps.newConcurrentMap();
+        }
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj instanceof DefaultPrometheusTelemetryConfig) {
+            final DefaultPrometheusTelemetryConfig other = (DefaultPrometheusTelemetryConfig) obj;
+            return Objects.equals(this.address, other.address) &&
+                    Objects.equals(this.port, other.port) &&
+                    Objects.equals(this.configMap, other.configMap);
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(address, port, configMap);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("address", address)
+                .add("port", port)
+                .add("configMap", configMap)
+                .toString();
+    }
+
+    @Override
+    public TelemetryConfig.Builder createBuilder() {
+        return new DefaultBuilder();
+    }
+
+    /**
+     * Builder class of DefaultPrometheusTelemetryConfig.
+     */
+    public static final class DefaultBuilder implements Builder {
+        private String address;
+        private int port;
+        private Map<String, Object> configMap;
+
+        @Override
+        public Builder withAddress(String address) {
+            this.address = address;
+            return this;
+        }
+
+        @Override
+        public Builder withPort(int port) {
+            this.port = port;
+            return this;
+        }
+
+        @Override
+        public Builder withConfigMap(Map<String, Object> configMap) {
+            this.configMap = configMap;
+            return this;
+        }
+        @Override
+        public PrometheusTelemetryConfig build() {
+            checkNotNull(address, "Prometheus exporter binding address cannot be null");
+            checkNotNull(configMap, "Config map cannot be null");
+            return new DefaultPrometheusTelemetryConfig(address, port, configMap);
+        }
+    }
+}
diff --git a/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/InfluxDbTelemetryManager.java b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/InfluxDbTelemetryManager.java
index e35d662..41a318b 100644
--- a/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/InfluxDbTelemetryManager.java
+++ b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/InfluxDbTelemetryManager.java
@@ -58,8 +58,6 @@
     private static final String SRC_PORT = "srcPort";
     private static final String DST_PORT = "dstPort";
     private static final String PROTOCOL = "protocol";
-    private static final String SRC_MAC = "srcMac";
-    private static final String DST_MAC = "dstMac";
 
     private static final String STARTUP_TIME = "startupTime";
     private static final String FST_PKT_ARR_TIME = "fstPktArrTime";
@@ -130,7 +128,7 @@
             producer = null;
         }
 
-        log.info("InfluxDB producer has Stopped");
+        log.info("InfluxDB producer has stopped");
     }
 
     @Override
diff --git a/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/OpenstackTelemetryManager.java b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/OpenstackTelemetryManager.java
index 761e01b..3e629cc 100644
--- a/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/OpenstackTelemetryManager.java
+++ b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/OpenstackTelemetryManager.java
@@ -30,6 +30,7 @@
 import org.onosproject.openstacktelemetry.api.InfluxDbTelemetryService;
 import org.onosproject.openstacktelemetry.api.KafkaTelemetryService;
 import org.onosproject.openstacktelemetry.api.OpenstackTelemetryService;
+import org.onosproject.openstacktelemetry.api.PrometheusTelemetryService;
 import org.onosproject.openstacktelemetry.api.RestTelemetryService;
 import org.onosproject.openstacktelemetry.api.TelemetryService;
 import org.onosproject.openstacktelemetry.codec.TinaMessageByteBufferCodec;
@@ -96,6 +97,12 @@
                 invokeInfluxDbPublisher((InfluxDbTelemetryService) service, flowInfos);
             }
 
+            if (service instanceof PrometheusTelemetryManager &&
+                    getPropertyValueAsBoolean(componentConfigService.getProperties(
+                            PrometheusTelemetryConfigManager.class.getName()), ENABLE_SERVICE)) {
+                invokePrometheusPublisher((PrometheusTelemetryService) service, flowInfos);
+            }
+
             if (service instanceof KafkaTelemetryManager &&
                     getPropertyValueAsBoolean(componentConfigService.getProperties(
                             KafkaTelemetryConfigManager.class.getName()), ENABLE_SERVICE)) {
@@ -127,6 +134,10 @@
         service.publish(influxRecord);
     }
 
+    private void invokePrometheusPublisher(PrometheusTelemetryService service, Set<FlowInfo> flowInfos) {
+        service.publish(flowInfos);
+    }
+
     private void invokeKafkaPublisher(KafkaTelemetryService service, Set<FlowInfo> flowInfos) {
         TinaMessageByteBufferCodec codec = new TinaMessageByteBufferCodec();
         ByteBuffer buffer = codec.encode(flowInfos);
diff --git a/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/PrometheusTelemetryConfigManager.java b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/PrometheusTelemetryConfigManager.java
new file mode 100644
index 0000000..23cc240
--- /dev/null
+++ b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/PrometheusTelemetryConfigManager.java
@@ -0,0 +1,140 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.openstacktelemetry.impl;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Modified;
+import org.apache.felix.scr.annotations.Property;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.util.Tools;
+import org.onosproject.cfg.ComponentConfigService;
+import org.onosproject.openstacktelemetry.api.PrometheusTelemetryAdminService;
+import org.onosproject.openstacktelemetry.api.PrometheusTelemetryConfigService;
+import org.onosproject.openstacktelemetry.api.config.TelemetryConfig;
+import org.onosproject.openstacktelemetry.config.DefaultPrometheusTelemetryConfig;
+import org.osgi.service.component.ComponentContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Dictionary;
+
+import static org.onosproject.openstacktelemetry.api.Constants.DEFAULT_DISABLE;
+import static org.onosproject.openstacktelemetry.api.Constants.DEFAULT_ENABLE;
+import static org.onosproject.openstacktelemetry.api.Constants.DEFAULT_PROMETHEUS_EXPORTER_IP;
+import static org.onosproject.openstacktelemetry.api.Constants.DEFAULT_PROMETHEUS_EXPORTER_PORT;
+import static org.onosproject.openstacktelemetry.util.OpenstackTelemetryUtil.getBooleanProperty;
+import static org.onosproject.openstacktelemetry.util.OpenstackTelemetryUtil.initTelemetryService;
+
+/**
+ * Prometheus exporter configuration manager for publishing openstack telemetry.
+ */
+@Component(immediate = true)
+@Service
+public class PrometheusTelemetryConfigManager implements PrometheusTelemetryConfigService {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private static final String ENABLE_SERVICE = "enableService";
+    private static final String ADDRESS = "address";
+    private static final String PORT = "port";
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ComponentConfigService componentConfigService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected PrometheusTelemetryAdminService prometheusTelemetryAdminService;
+
+    @Property(name = ADDRESS, value = DEFAULT_PROMETHEUS_EXPORTER_IP,
+            label = "Default IP address of prometheus exporter")
+    protected String address = DEFAULT_PROMETHEUS_EXPORTER_IP;
+
+    @Property(name = PORT, intValue = DEFAULT_PROMETHEUS_EXPORTER_PORT,
+            label = "Default port number of prometheus exporter")
+    protected Integer port = DEFAULT_PROMETHEUS_EXPORTER_PORT;
+
+    @Property(name = ENABLE_SERVICE, boolValue = DEFAULT_ENABLE,
+            label = "Specify the default behavior of telemetry service")
+    protected Boolean enableService = DEFAULT_ENABLE;
+
+    @Activate
+    protected void activate(ComponentContext context) {
+        componentConfigService.registerProperties(getClass());
+        if (enableService) {
+            prometheusTelemetryAdminService.start(getConfig());
+        }
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        componentConfigService.unregisterProperties(getClass(), false);
+        if (enableService) {
+            prometheusTelemetryAdminService.stop();
+        }
+        log.info("Stopped");
+    }
+
+    @Modified
+    private void modified(ComponentContext context) {
+        readComponentConfiguration(context);
+        initTelemetryService(prometheusTelemetryAdminService, getConfig(), enableService);
+        log.info("Modified");
+    }
+
+    @Override
+    public TelemetryConfig getConfig() {
+        return new DefaultPrometheusTelemetryConfig.DefaultBuilder()
+                .withAddress(address)
+                .withPort(port)
+                .build();
+    }
+
+    /**
+     * Extracts properties from the component configuration context.
+     *
+     * @param context the component context
+     */
+    private void readComponentConfiguration(ComponentContext context) {
+        Dictionary<?, ?> properties = context.getProperties();
+
+        String addressStr = Tools.get(properties, ADDRESS);
+        address = addressStr != null ? addressStr : DEFAULT_PROMETHEUS_EXPORTER_IP;
+        log.info("Configured. Prometheus exporter address is {}", address);
+
+        Integer portConfigured = Tools.getIntegerProperty(properties, PORT);
+        if (portConfigured == null) {
+            port = DEFAULT_PROMETHEUS_EXPORTER_PORT;
+            log.info("Prometheus exporter port is NOT configured, default value is {}", port);
+        } else {
+            port = portConfigured;
+            log.info("Configured. Prometheus exporter port is {}", port);
+        }
+
+        Boolean enableServiceConfigured = getBooleanProperty(properties, ENABLE_SERVICE);
+        if (enableServiceConfigured == null) {
+            enableService = DEFAULT_DISABLE;
+            log.info("Prometheus service enable flag is NOT " +
+                             "configured, default value is {}", enableService);
+        } else {
+            enableService = enableServiceConfigured;
+            log.info("Configured. Prometheus service enable flag is {}", enableService);
+        }
+    }
+}
diff --git a/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/PrometheusTelemetryManager.java b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/PrometheusTelemetryManager.java
new file mode 100644
index 0000000..f06a961
--- /dev/null
+++ b/apps/openstacktelemetry/app/src/main/java/org/onosproject/openstacktelemetry/impl/PrometheusTelemetryManager.java
@@ -0,0 +1,196 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.openstacktelemetry.impl;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onosproject.openstacktelemetry.api.FlowInfo;
+import org.onosproject.openstacktelemetry.api.OpenstackTelemetryService;
+import org.onosproject.openstacktelemetry.api.PrometheusTelemetryAdminService;
+import org.onosproject.openstacktelemetry.api.config.PrometheusTelemetryConfig;
+import org.onosproject.openstacktelemetry.api.config.TelemetryConfig;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import io.prometheus.client.Counter;
+import io.prometheus.client.exporter.MetricsServlet;
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.servlet.ServletContextHandler;
+import org.eclipse.jetty.servlet.ServletHolder;
+import java.util.Set;
+
+/**
+ * Prometheus telemetry manager.
+ */
+@Component(immediate = true)
+@Service
+public class PrometheusTelemetryManager implements PrometheusTelemetryAdminService {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private Server prometheusExporter;
+
+    private static final String BYTE_VM2VM = "byte_vm2vm";
+    private static final String BYTE_DEVICE = "byte_device";
+    private static final String BYTE_SRC_IP = "byte_src_ip";
+    private static final String BYTE_DST_IP = "byte_dst_ip";
+
+    private static final String PKT_VM2VM = "pkt_vm2vm";
+    private static final String PKT_DEVICE = "pkt_device";
+    private static final String PKT_SRC_IP = "pkt_src_ip";
+    private static final String PKT_DST_IP = "pkt_dst_ip";
+
+    private static final String PKT_ERROR = "pkt_error";
+    private static final String PKT_DROP = "pkt_drop";
+
+    private static final String LABEL_IP_5_TUPLE = "IP_5_TUPLE";
+    private static final String LABEL_DEV_ID = "DEVICE_ID";
+    private static final String LABEL_SRC_IP = "SOURCE_IP";
+    private static final String LABEL_DST_IP = "DESTINATION_IP";
+
+    private static final String HELP_MSG = "SONA Flow statistics";
+
+    private static Counter byteVM2VM = Counter.build().name(BYTE_VM2VM)
+                                    .help(HELP_MSG)
+                                    .labelNames(LABEL_IP_5_TUPLE).register();
+
+    private static Counter byteDevice = Counter.build().name(BYTE_DEVICE)
+                                    .help(HELP_MSG)
+                                    .labelNames(LABEL_DEV_ID).register();
+
+    private static Counter byteSrcIp = Counter.build().name(BYTE_SRC_IP)
+                                    .help(HELP_MSG)
+                                    .labelNames(LABEL_SRC_IP).register();
+
+    private static Counter byteDstIp = Counter.build().name(BYTE_DST_IP)
+                                    .help(HELP_MSG)
+                                    .labelNames(LABEL_DST_IP).register();
+
+    private static Counter pktVM2VM = Counter.build().name(PKT_VM2VM)
+                                    .help(HELP_MSG)
+                                    .labelNames(LABEL_IP_5_TUPLE).register();
+
+    private static Counter pktDevice = Counter.build().name(PKT_DEVICE)
+                                    .help(HELP_MSG)
+                                    .labelNames(LABEL_DEV_ID).register();
+
+    private static Counter pktSrcIp = Counter.build().name(PKT_SRC_IP)
+                                    .help(HELP_MSG)
+                                    .labelNames(LABEL_SRC_IP).register();
+
+    private static Counter pktDstIp = Counter.build().name(PKT_DST_IP)
+                                    .help(HELP_MSG)
+                                    .labelNames(LABEL_DST_IP).register();
+
+    private static Counter pktError = Counter.build().name(PKT_ERROR)
+                                    .help(HELP_MSG)
+                                    .register();
+    private static Counter pktDrop = Counter.build().name(PKT_DROP)
+                                    .help(HELP_MSG)
+                                    .register();
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected OpenstackTelemetryService openstackTelemetryService;
+
+    @Activate
+    protected void activate() {
+        openstackTelemetryService.addTelemetryService(this);
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        stop();
+        openstackTelemetryService.removeTelemetryService(this);
+        log.info("Stopped");
+    }
+
+    @Override
+    public void start(TelemetryConfig config) {
+        log.info("Prometheus exporter starts.");
+
+        PrometheusTelemetryConfig prometheusConfig = (PrometheusTelemetryConfig) config;
+
+        try {
+            // TODO  Offer a 'Authentication'
+            prometheusExporter = new Server(prometheusConfig.port());
+            ServletContextHandler context = new ServletContextHandler();
+            context.setContextPath("/");
+            prometheusExporter.setHandler(context);
+            context.addServlet(new ServletHolder(new MetricsServlet()), "/metrics");
+
+            log.info("Prometeus server start");
+
+            prometheusExporter.start();
+        } catch (Exception ex) {
+            log.warn("Exception: {}", ex.toString());
+        }
+    }
+
+    @Override
+    public void stop() {
+        try {
+            prometheusExporter.stop();
+        } catch (Exception ex) {
+            log.warn("Exception: {}", ex.toString());
+        }
+        log.info("Prometheus exporter has stopped");
+    }
+
+    @Override
+    public void restart(TelemetryConfig config) {
+        stop();
+        start(config);
+    }
+
+    @Override
+    public void publish(Set<FlowInfo> flowInfos) {
+        if (flowInfos.size() == 0) {
+            log.debug("No record to publish");
+            return;
+        }
+
+        long flowByte;
+        int flowPkt;
+        for (FlowInfo flowInfo: flowInfos) {
+            flowByte = flowInfo.statsInfo().currAccBytes() - flowInfo.statsInfo().prevAccBytes();
+            flowPkt = flowInfo.statsInfo().currAccPkts() - flowInfo.statsInfo().prevAccPkts();
+
+            byteVM2VM.labels(flowInfo.uniqueFlowInfoKey()).inc(flowByte);
+            byteDevice.labels(flowInfo.deviceId().toString()).inc(flowByte);
+            byteSrcIp.labels(flowInfo.srcIp().toString()).inc(flowByte);
+            byteDstIp.labels(flowInfo.dstIp().toString()).inc(flowByte);
+
+            pktVM2VM.labels(flowInfo.uniqueFlowInfoKey()).inc(flowPkt);
+            pktDevice.labels(flowInfo.deviceId().toString()).inc(flowPkt);
+            pktSrcIp.labels(flowInfo.srcIp().toString()).inc(flowPkt);
+            pktDstIp.labels(flowInfo.dstIp().toString()).inc(flowPkt);
+
+            pktError.inc(flowInfo.statsInfo().errorPkts());
+            pktDrop.inc(flowInfo.statsInfo().dropPkts());
+        }
+    }
+
+    @Override
+    public boolean isRunning() {
+        log.info("Prometheus Exporter State: {}", prometheusExporter.isRunning());
+        return prometheusExporter.isRunning();
+    }
+}
diff --git a/apps/openstacktelemetry/app/src/test/java/org/onosproject/openstacktelemetry/config/DefaultPrometheusTelemetryConfigTest.java b/apps/openstacktelemetry/app/src/test/java/org/onosproject/openstacktelemetry/config/DefaultPrometheusTelemetryConfigTest.java
new file mode 100644
index 0000000..3e291c2
--- /dev/null
+++ b/apps/openstacktelemetry/app/src/test/java/org/onosproject/openstacktelemetry/config/DefaultPrometheusTelemetryConfigTest.java
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.openstacktelemetry.config;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.testing.EqualsTester;
+import org.junit.Before;
+import org.junit.Test;
+import org.onosproject.openstacktelemetry.api.config.PrometheusTelemetryConfig;
+
+import java.util.Map;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+import static org.onosproject.openstacktelemetry.api.Constants.DEFAULT_PROMETHEUS_EXPORTER_IP;
+import static org.onosproject.openstacktelemetry.api.Constants.DEFAULT_PROMETHEUS_EXPORTER_PORT;
+
+/**
+ * Unit tests for DefaultPrometheusTelemetryConfig class.
+ */
+public class DefaultPrometheusTelemetryConfigTest {
+
+    private static final String IP_ADDRESS_1 = DEFAULT_PROMETHEUS_EXPORTER_IP;
+    private static final String IP_ADDRESS_2 = "10.10.1.2";
+
+    private static final int PORT_1 = DEFAULT_PROMETHEUS_EXPORTER_PORT;
+    private static final int PORT_2 = DEFAULT_PROMETHEUS_EXPORTER_PORT + 1;
+
+    private static final Map<String, Object> CONFIG_MAP_1 =
+            ImmutableMap.of("key1", "value1");
+    private static final Map<String, Object> CONFIG_MAP_2 =
+            ImmutableMap.of("key2", "value2");
+
+    private PrometheusTelemetryConfig config1;
+    private PrometheusTelemetryConfig sameAsConfig1;
+    private PrometheusTelemetryConfig config2;
+
+    /**
+     * Initial setup for this unit test.
+     */
+    @Before
+    public void setup() {
+
+        PrometheusTelemetryConfig.Builder builder1 =
+                new DefaultPrometheusTelemetryConfig.DefaultBuilder();
+        PrometheusTelemetryConfig.Builder builder2 =
+                new DefaultPrometheusTelemetryConfig.DefaultBuilder();
+        PrometheusTelemetryConfig.Builder builder3 =
+                new DefaultPrometheusTelemetryConfig.DefaultBuilder();
+
+        config1 = builder1
+                .withAddress(IP_ADDRESS_1)
+                .withPort(PORT_1)
+                .withConfigMap(CONFIG_MAP_1)
+                .build();
+
+        sameAsConfig1 = builder2
+                .withAddress(IP_ADDRESS_1)
+                .withPort(PORT_1)
+                .withConfigMap(CONFIG_MAP_1)
+                .build();
+
+        config2 = builder3
+                .withAddress(IP_ADDRESS_2)
+                .withPort(PORT_2)
+                .withConfigMap(CONFIG_MAP_2)
+                .build();
+    }
+
+    /**
+     * Tests class immutability.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(DefaultPrometheusTelemetryConfig.class);
+    }
+
+    /**
+     * Tests object equality.
+     */
+    @Test
+    public void testEquality() {
+        new EqualsTester()
+                .addEqualityGroup(config1, sameAsConfig1)
+                .addEqualityGroup(config2).testEquals();
+    }
+
+    /**
+     * Tests object construction.
+     */
+    @Test
+    public void testConstruction() {
+        PrometheusTelemetryConfig config = config1;
+
+        assertThat(config.address(), is(IP_ADDRESS_1));
+        assertThat(config.port(), is(PORT_1));
+        assertThat(config.configMap(), is(CONFIG_MAP_1));
+    }
+}