Add a simple status endpoint

hawkular-alerts-rest/src/main/java/org/hawkular/alerts/rest/ManifestUtil.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 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.alerts.rest;
+
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.jar.Attributes;
+import java.util.jar.Manifest;
+
+import javax.enterprise.context.ApplicationScoped;
+import javax.servlet.ServletContext;
+
+import com.google.common.collect.ImmutableList;
+
+/**
+ * Manifest extraction.
+ * Credits to Hawkular Metrics team.
+ *
+ * @author Jay Shaughnessy
+ * @author Lucas Ponce
+ */
+@ApplicationScoped
+public class ManifestUtil {
+    private static final String IMPLEMENTATION_VERSION = "Implementation-Version";
+    private static final String BUILT_FROM_GIT = "Built-From-Git-SHA1";
+
+    private static final List<String> VERSION_ATTRIBUTES = ImmutableList.of(IMPLEMENTATION_VERSION,
+            BUILT_FROM_GIT);
+
+    private Map<String, String> manifestInformation = new HashMap<>();
+
+    public Map<String, String> getFrom(ServletContext servletContext) {
+        if (!manifestInformation.containsKey(IMPLEMENTATION_VERSION) &&
+                !manifestInformation.containsKey(BUILT_FROM_GIT)) {
+            try (InputStream inputStream = servletContext.getResourceAsStream("/META-INF/MANIFEST.MF")) {
+                Manifest manifest = new Manifest(inputStream);
+                Attributes attr = manifest.getMainAttributes();
+                for (String attribute : VERSION_ATTRIBUTES) {
+                    manifestInformation.put(attribute, attr.getValue(attribute));
+                }
+            } catch (Exception e) {
+                for (String attribute : VERSION_ATTRIBUTES) {
+                    if (manifestInformation.get(attribute) == null) {
+                        manifestInformation.put(attribute, "Unknown");
+                    }
+                }
+            }
+        }
+        return manifestInformation;
+    }
+}

hawkular-alerts-rest/src/main/java/org/hawkular/alerts/rest/StatusHandler.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 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.alerts.rest;
+
+import static javax.ws.rs.core.MediaType.APPLICATION_JSON;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.ejb.EJB;
+import javax.inject.Inject;
+import javax.servlet.ServletContext;
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.Response;
+
+import org.hawkular.alerts.api.services.DefinitionsService;
+
+import com.wordnik.swagger.annotations.Api;
+
+/**
+ * REST endpoint for status
+ *
+ * @author Jay Shaughnessy
+ * @author Lucas Ponce
+ */
+@Path("/status")
+@Api(value = "/status", description = "Status of Alerts Service")
+public class StatusHandler {
+    private static final String STATUS = "status";
+    private static final String STARTED = "STARTED";
+    private static final String FAILED = "FAILED";
+
+    @EJB
+    DefinitionsService definitionsService;
+
+    @Inject
+    ManifestUtil manifestUtil;
+
+    @GET
+    @Path("/")
+    @Produces(APPLICATION_JSON)
+    public Response status(@Context ServletContext servletContext) {
+        Map<String, String> status = new HashMap<>();
+        status.putAll(manifestUtil.getFrom(servletContext));
+        try {
+            definitionsService.getActionPlugins();
+            status.put(STATUS, STARTED);
+        } catch (Exception e) {
+            status.put(STATUS, FAILED);
+        }
+        return ResponseUtil.ok(status);
+    }
+
+}