[Falcon][ONOS-3601] Add REST API for metrics service with unit test

Change-Id: I33ec561d1d83c6f1167e960bc2f684a117e6ea9c

@@ -15,6 +15,7 @@
  */
 package org.onosproject.codec.impl;
 
+import com.codahale.metrics.Metric;
 import com.google.common.collect.ImmutableSet;
 
 import org.apache.felix.scr.annotations.Activate;
@@ -104,6 +105,7 @@ public class CodecManager implements CodecService {
         registerCodec(Load.class, new LoadCodec());
         registerCodec(TableStatisticsEntry.class, new TableStatisticsEntryCodec());
         registerCodec(PortStatistics.class, new PortStatisticsCodec());
+        registerCodec(Metric.class, new MetricCodec());
         log.info("Started");
     }
 

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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.codec.impl;
+
+import com.codahale.metrics.Counter;
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.Meter;
+import com.codahale.metrics.Metric;
+import com.codahale.metrics.Histogram;
+import com.codahale.metrics.Timer;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Codec for the Metric class.
+ */
+public class MetricCodec extends JsonCodec<Metric> {
+
+    // JSON field names
+    private static final String COUNTER = "counter";
+
+    private static final String GAUGE = "gauge";
+    private static final String VALUE = "value";
+
+    private static final String METER = "meter";
+    private static final String MEAN_RATE = "mean_rate";
+    private static final String ONE_MIN_RATE = "1_min_rate";
+    private static final String FIVE_MIN_RATE = "5_min_rate";
+    private static final String FIFT_MIN_RATE = "15_min_rate";
+
+    private static final String HISTOGRAM = "histogram";
+    private static final String MIN = "min";
+    private static final String MAX = "max";
+    private static final String MEAN = "mean";
+    private static final String STDDEV = "stddev";
+
+    private static final String TIMER = "timer";
+
+    @Override
+    public ObjectNode encode(Metric metric, CodecContext context) {
+        checkNotNull(metric, "Metric cannot be null");
+
+        ObjectNode objectNode = context.mapper().createObjectNode();
+        ObjectNode dataNode = context.mapper().createObjectNode();
+
+        if (metric instanceof Counter) {
+            dataNode.put(COUNTER, ((Counter) metric).getCount());
+            objectNode.set(COUNTER, dataNode);
+        } else if (metric instanceof Gauge) {
+            objectNode.put(VALUE, ((Gauge) metric).getValue().toString());
+            objectNode.set(GAUGE, dataNode);
+        } else if (metric instanceof Meter) {
+            dataNode.put(COUNTER, ((Meter) metric).getCount());
+            dataNode.put(MEAN_RATE, ((Meter) metric).getMeanRate());
+            dataNode.put(ONE_MIN_RATE, ((Meter) metric).getOneMinuteRate());
+            dataNode.put(FIVE_MIN_RATE, ((Meter) metric).getFiveMinuteRate());
+            dataNode.put(FIFT_MIN_RATE, ((Meter) metric).getFifteenMinuteRate());
+            objectNode.set(METER, dataNode);
+        } else if (metric instanceof Histogram) {
+            dataNode.put(COUNTER, ((Histogram) metric).getCount());
+            dataNode.put(MEAN, ((Histogram) metric).getSnapshot().getMean());
+            dataNode.put(MIN, ((Histogram) metric).getSnapshot().getMin());
+            dataNode.put(MAX, ((Histogram) metric).getSnapshot().getMax());
+            dataNode.put(STDDEV, ((Histogram) metric).getSnapshot().getStdDev());
+            objectNode.set(HISTOGRAM, dataNode);
+        } else if (metric instanceof Timer) {
+            dataNode.put(COUNTER, ((Timer) metric).getCount());
+            dataNode.put(MEAN_RATE, ((Timer) metric).getMeanRate());
+            dataNode.put(ONE_MIN_RATE, ((Timer) metric).getOneMinuteRate());
+            dataNode.put(FIVE_MIN_RATE, ((Timer) metric).getFiveMinuteRate());
+            dataNode.put(FIFT_MIN_RATE, ((Timer) metric).getFifteenMinuteRate());
+            dataNode.put(MEAN, nanoToMs(((Timer) metric).getSnapshot().getMean()));
+            dataNode.put(MIN, nanoToMs(((Timer) metric).getSnapshot().getMin()));
+            dataNode.put(MAX, nanoToMs(((Timer) metric).getSnapshot().getMax()));
+            dataNode.put(STDDEV, nanoToMs(((Timer) metric).getSnapshot().getStdDev()));
+            objectNode.set(TIMER, dataNode);
+        }
+        return objectNode;
+    }
+
+    private double nanoToMs(double nano) {
+        return nano / 1_000_000D;
+    }
+}

@@ -102,7 +102,9 @@
                             org.onlab.osgi.*,
                             org.onlab.packet.*,
                             org.onlab.rest.*,
-                            org.onosproject.*
+                            org.onosproject.*,
+                            org.onlab.metrics.*,
+                            com.codahale.metrics.*
                         </Import-Package>
                         <Web-ContextPath>${web.context}</Web-ContextPath>
                     </instructions>

@@ -40,7 +40,8 @@ public class CoreWebApplication extends AbstractWebApplication {
                           TopologyWebResource.class,
                           ConfigWebResource.class,
                           PathsWebResource.class,
-                          StatisticsWebResource.class
+                          StatisticsWebResource.class,
+                          MetricsWebResource.class
         );
     }
 }

+/*
+ * Copyright 2014-2015 Open Networking Laboratory
+ *
+ * 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.rest.resources;
+
+import com.codahale.metrics.Counter;
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.Metric;
+import com.codahale.metrics.Histogram;
+import com.codahale.metrics.Meter;
+import com.codahale.metrics.Timer;
+import com.codahale.metrics.MetricFilter;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.google.common.collect.Ordering;
+import com.google.common.collect.TreeMultimap;
+import org.onlab.metrics.MetricsService;
+import org.onosproject.rest.AbstractWebResource;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import java.util.Comparator;
+import java.util.Map;
+
+/**
+ * Query metrics.
+ */
+@Path("metrics")
+public class MetricsWebResource extends AbstractWebResource {
+
+    final MetricsService service = get(MetricsService.class);
+    final ObjectNode root = mapper().createObjectNode();
+
+    /**
+     * Get stats information of all metrics. Returns array of all information for
+     * all metrics.
+     *
+     * @return metric information as array
+     * @onos.rsModel Metrics
+     */
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response getAllMetrics() {
+        ArrayNode metricsNode = root.putArray("metrics");
+        service.getMetrics().forEach((name, metric) -> {
+            ObjectNode item = mapper().createObjectNode();
+            item.put("name", name);
+            item.set("metric", codec(Metric.class).encode(metric, this));
+            metricsNode.add(item);
+        });
+
+        return ok(root).build();
+    }
+
+    /**
+     * Get stats information of a metric. Returns array of all information for the
+     * specified metric.
+     *
+     * @param metricName metric name
+     * @return metric information as array
+     * @onos.rsModel Metric
+     */
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    @Path("{metricName}")
+    public Response getMetricByName(@PathParam("metricName") String metricName) {
+        ObjectNode metricNode = root.putObject("metric");
+        MetricFilter filter = metricName != null ? (name, metric) -> name.equals(metricName) : MetricFilter.ALL;
+        TreeMultimap<String, Metric> matched = listMetrics(service, filter);
+
+        matched.asMap().get(metricName).forEach(m -> {
+            metricNode.set(metricName, codec(Metric.class).encode(m, this));
+        });
+
+        return ok(root).build();
+    }
+
+    private TreeMultimap<String, Metric> listMetrics(MetricsService metricsService, MetricFilter filter) {
+        TreeMultimap<String, Metric> metrics = TreeMultimap.create(Comparator.naturalOrder(), Ordering.arbitrary());
+
+        Map<String, Counter> counters = metricsService.getCounters(filter);
+        for (Map.Entry<String, Counter> entry : counters.entrySet()) {
+            metrics.put(entry.getKey(), entry.getValue());
+        }
+        Map<String, Gauge> gauges = metricsService.getGauges(filter);
+        for (Map.Entry<String, Gauge> entry : gauges.entrySet()) {
+            metrics.put(entry.getKey(), entry.getValue());
+        }
+        Map<String, Histogram> histograms = metricsService.getHistograms(filter);
+        for (Map.Entry<String, Histogram> entry : histograms.entrySet()) {
+            metrics.put(entry.getKey(), entry.getValue());
+        }
+        Map<String, Meter> meters = metricsService.getMeters(filter);
+        for (Map.Entry<String, Meter> entry : meters.entrySet()) {
+            metrics.put(entry.getKey(), entry.getValue());
+        }
+        Map<String, Timer> timers = metricsService.getTimers(filter);
+        for (Map.Entry<String, Timer> entry : timers.entrySet()) {
+            metrics.put(entry.getKey(), entry.getValue());
+        }
+
+        return metrics;
+    }
+}

+{
+  "type": "object",
+  "title": "metric",
+  "required": [
+    "name",
+    "metric"
+  ],
+  "properties": {
+    "name": {
+      "type": "string",
+      "example": "cpu"
+    },
+    "metric": {
+      "type": "object",
+      "title": "metric",
+      "optional": [
+        "counter",
+        "gauge",
+        "meter",
+        "histogram",
+        "timer"
+      ],
+      "properties": {
+        "counter": {
+          "type": "object",
+          "required": [
+            "counter"
+          ],
+          "properties": {
+            "counter": {
+              "type": "integer",
+              "example": "1"
+            }
+          }
+        },
+        "gauge": {
+          "type": "object",
+          "required": [
+            "value"
+          ],
+          "properties": {
+            "value": "string",
+            "example": "1"
+          }
+        },
+        "meter": {
+          "type": "object",
+          "required": [
+            "counter",
+            "mean_rate",
+            "1_min_rate",
+            "5_min_rate",
+            "15_min_rate"
+          ],
+          "properties": {
+            "counter": {
+              "type": "integer",
+              "example": "1"
+            },
+            "mean_rate": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "1_min_rate": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "5_min_rate": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "15_min_rate": {
+              "type": "double",
+              "example": "1.0"
+            }
+          }
+        },
+        "histogram": {
+          "type": "object",
+          "required": [
+            "counter",
+            "mean",
+            "min",
+            "max",
+            "stddev"
+          ],
+          "properties": {
+            "counter": {
+              "type": "integer",
+              "example": "1"
+            },
+            "mean": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "min": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "max": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "stddev": {
+              "type": "double",
+              "example": "1.0"
+            }
+          }
+        },
+        "timer": {
+          "type": "object",
+          "required": [
+            "counter",
+            "mean_rate",
+            "1_min_rate",
+            "5_min_rate",
+            "15_min_rate",
+            "mean",
+            "min",
+            "max",
+            "stddev"
+          ],
+          "properties": {
+            "counter": {
+              "type": "integer",
+              "example": "1"
+            },
+            "mean_rate": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "1_min_rate": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "5_min_rate": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "15_min_rate": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "mean": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "min": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "max": {
+              "type": "double",
+              "example": "1.0"
+            },
+            "stddev": {
+              "type": "double",
+              "example": "1.0"
+            }
+          }
+        }
+      }
+    }
+  }
+}
\ No newline at end of file

+{
+  "type": "object",
+  "title": "metrics",
+  "required": [
+    "metrics"
+  ],
+  "properties": {
+    "metrics": {
+      "type": "array",
+      "xml": {
+        "name": "metrics",
+        "wrapped": true
+      },
+      "items": {
+        "type": "object",
+        "title": "metric",
+        "required": [
+          "name",
+          "metric"
+        ],
+        "properties": {
+          "name": {
+            "type": "string",
+            "example": "cpu"
+          },
+          "metric": {
+            "type": "object",
+            "optional": [
+              "counter",
+              "gauge",
+              "meter",
+              "histogram",
+              "timer"
+            ],
+            "properties": {
+              "counter": {
+                "type": "object",
+                "required": [
+                  "counter"
+                ],
+                "properties": {
+                  "counter": {
+                    "type": "integer",
+                    "example": "1"
+                  }
+                }
+              },
+              "gauge": {
+                "type": "object",
+                "required": [
+                  "value"
+                ],
+                "properties": {
+                  "value": "string",
+                  "example": "1"
+                }
+              },
+              "meter": {
+                "type": "object",
+                "required": [
+                  "counter",
+                  "mean_rate",
+                  "1_min_rate",
+                  "5_min_rate",
+                  "15_min_rate"
+                ],
+                "properties": {
+                  "counter": {
+                    "type": "integer",
+                    "example": "1"
+                  },
+                  "mean_rate": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "1_min_rate": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "5_min_rate": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "15_min_rate": {
+                    "type": "double",
+                    "example": "1.0"
+                  }
+                }
+              },
+              "histogram": {
+                "type": "object",
+                "required": [
+                  "counter",
+                  "mean",
+                  "min",
+                  "max",
+                  "stddev"
+                ],
+                "properties": {
+                  "counter": {
+                    "type": "integer",
+                    "example": "1"
+                  },
+                  "mean": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "min": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "max": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "stddev": {
+                    "type": "double",
+                    "example": "1.0"
+                  }
+                }
+              },
+              "timer": {
+                "type": "object",
+                "required": [
+                  "counter",
+                  "mean_rate",
+                  "1_min_rate",
+                  "5_min_rate",
+                  "15_min_rate",
+                  "mean",
+                  "min",
+                  "max",
+                  "stddev"
+                ],
+                "properties": {
+                  "counter": {
+                    "type": "integer",
+                    "example": "1"
+                  },
+                  "mean_rate": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "1_min_rate": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "5_min_rate": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "15_min_rate": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "mean": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "min": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "max": {
+                    "type": "double",
+                    "example": "1.0"
+                  },
+                  "stddev": {
+                    "type": "double",
+                    "example": "1.0"
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
\ No newline at end of file

+/*
+ * Copyright 2014-2015 Open Networking Laboratory
+ *
+ * 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.rest;
+
+import com.codahale.metrics.Counter;
+import com.codahale.metrics.Meter;
+import com.codahale.metrics.Metric;
+import com.eclipsesource.json.JsonArray;
+import com.eclipsesource.json.JsonObject;
+import com.google.common.collect.ImmutableMap;
+import com.sun.jersey.api.client.WebResource;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.metrics.MetricsService;
+import org.onlab.osgi.ServiceDirectory;
+import org.onlab.osgi.TestServiceDirectory;
+import org.onlab.rest.BaseResource;
+import org.onosproject.codec.CodecService;
+import org.onosproject.codec.impl.CodecManager;
+
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.easymock.EasyMock.verify;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Unit tests for Metrics REST APIs.
+ */
+public class MetricsResourceTest extends ResourceTest {
+    MetricsService mockMetricsService;
+
+    /**
+     * Initializes test mocks and environment.
+     */
+    @Before
+    public void setUpTest() {
+        mockMetricsService = createMock(MetricsService.class);
+
+        // Register the services needed for the test
+        final CodecManager codecService = new CodecManager();
+        codecService.activate();
+        ServiceDirectory testDirectory =
+                new TestServiceDirectory()
+                        .add(MetricsService.class, mockMetricsService)
+                        .add(CodecService.class, codecService);
+        BaseResource.setServiceDirectory(testDirectory);
+    }
+
+    /**
+     * Verifies mocks.
+     */
+    @After
+    public void tearDownTest() {
+        verify(mockMetricsService);
+    }
+
+    /**
+     * Tests that a fetch of a non-existent object throws an exception.
+     */
+    @Test
+    public void testBadGet() {
+        Counter onosCounter = new Counter();
+        onosCounter.inc();
+
+        Meter onosMeter = new Meter();
+        onosMeter.mark();
+
+        ImmutableMap<String, Metric> metrics =
+                new ImmutableMap.Builder<String, Metric>()
+                        .put("onosCounter", onosCounter)
+                        .put("onosMeter", onosMeter)
+                        .build();
+
+        expect(mockMetricsService.getMetrics())
+                .andReturn(metrics)
+                .anyTimes();
+
+        replay(mockMetricsService);
+
+        WebResource rs = resource();
+        String response = rs.path("metrics").get(String.class);
+        assertThat(response, containsString("{\"metrics\":["));
+
+        JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        JsonArray jsonMetrics = result.get("metrics").asArray();
+        assertThat(jsonMetrics, notNullValue());
+        assertThat(jsonMetrics.size(), is(2));
+    }
+}