HWKMETRICS-104: Create a status endpoint to display the state of thin…

…gs such as the MetricsService

api/metrics-api-jaxrs/src/main/java/org/hawkular/metrics/api/jaxrs/filter/MetricsServiceStateFilter.java

@@ -16,7 +16,9 @@
  */
 package org.hawkular.metrics.api.jaxrs.filter;
 
+import javax.ws.rs.core.UriInfo;
 import org.hawkular.metrics.api.jaxrs.ApiError;
+import org.hawkular.metrics.api.jaxrs.handler.StatusHandler;
 import org.hawkular.metrics.core.api.MetricsService;
 
 import javax.inject.Inject;
@@ -44,6 +46,14 @@ public class MetricsServiceStateFilter implements ContainerRequestFilter {
 
     @Override
     public void filter(ContainerRequestContext containerRequestContext) throws IOException {
+        UriInfo uriInfo = containerRequestContext.getUriInfo();
+        String path = uriInfo.getPath();
+
+        if (path.startsWith(StatusHandler.PATH)) {
+            // The status page does not require the MetricsService to be up and running.
+            return;
+        }
+
         if (metricsService.getState() == MetricsService.State.STARTING) {
             // Fail since the Cassandra cluster is not yet up yet.
             Response response = Response.status(Response.Status.SERVICE_UNAVAILABLE)

api/metrics-api-jaxrs/src/main/java/org/hawkular/metrics/api/jaxrs/filter/TenantFilter.java

@@ -28,6 +28,7 @@
 import javax.ws.rs.ext.Provider;
 
 import org.hawkular.metrics.api.jaxrs.ApiError;
+import org.hawkular.metrics.api.jaxrs.handler.StatusHandler;
 
 /**
  * @author Stefan Negrea
@@ -52,8 +53,8 @@ public void filter(ContainerRequestContext requestContext) throws IOException {
         UriInfo uriInfo = requestContext.getUriInfo();
         String path = uriInfo.getPath();
 
-        if (path.startsWith("/tenants") || path.startsWith("/db")) {
-            // Tenants and Influx handlers do not check the tenant header
+        if (path.startsWith("/tenants") || path.startsWith("/db") || path.startsWith(StatusHandler.PATH)) {
+            // Tenants, Influx and status handlers do not check the tenant header
             return;
         }
 

api/metrics-api-jaxrs/src/main/java/org/hawkular/metrics/api/jaxrs/handler/StatusHandler.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2014-2015 Red Hat, Inc. and/or its affiliates
+ * and other contributors as indicated by the @author tags.
+ *
+ * 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.hawkular.metrics.api.jaxrs.handler;
+
+import static javax.ws.rs.core.MediaType.APPLICATION_JSON;
+
+import com.wordnik.swagger.annotations.ApiOperation;
+import java.util.HashMap;
+import java.util.Map;
+import javax.inject.Inject;
+import javax.ws.rs.Consumes;
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Response;
+import org.hawkular.metrics.core.api.MetricsService;
+
+/**
+ * @author mwringe
+ */
+@Path("/status")
+@Produces(APPLICATION_JSON)
+public class StatusHandler {
+
+    public static final String PATH = "/status";
+
+    @Inject
+    private MetricsService metricsService;
+
+    private static final String METRICSSERVICE_NAME = "MetricsService";
+
+    @GET
+    @ApiOperation(value = "Returns the current status for various components.",
+                  response = String.class, responseContainer = "Map")
+    public Response status() {
+        Map<String, Object> status = new HashMap();
+
+        MetricsService.State metricState = metricsService.getState();
+        status.put(METRICSSERVICE_NAME, metricState.toString());
+
+        return Response.ok(status).build();
+    }
+}

rest-tests/src/test/groovy/org/hawkular/metrics/rest/StatusITest.groovy

@@ -0,0 +1,38 @@
+/**
+ * Copyright 2014-2015 Red Hat, Inc. and/or its affiliates
+ * and other contributors as indicated by the @author tags.
+ *
+ * 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.hawkular.metrics.rest
+
+import org.junit.Test
+import static org.junit.Assert.assertEquals
+
+/**
+ * @author mwringe
+ */
+class StatusITest extends RESTTest {
+    @Test
+    void getStatusTest() {
+        def response = hawkularMetrics.get(path: "status");
+
+        assertEquals(200, response.status);
+
+        println("response: " + response.data);
+
+        def expectedData = ["MetricsService" : "STARTED"];
+
+        assertEquals(expectedData, response.data);
+    }
+}