bot: add version handler

Reviewed-by: erikj

bot/build.gradle

@@ -39,6 +39,7 @@ dependencies {
     implementation project(':json')
     implementation project(':census')
     implementation project(':metrics')
+    implementation project(':version')
 }
 
 publishing {

bot/src/main/java/module-info.java

@@ -30,6 +30,7 @@
     requires transitive org.openjdk.skara.metrics;
     requires org.openjdk.skara.network;
     requires org.openjdk.skara.vcs;
+    requires org.openjdk.skara.version;
     requires java.logging;
     requires java.management;
     requires jdk.management;

bot/src/main/java/org/openjdk/skara/bot/BotRunnerConfiguration.java

@@ -408,7 +408,8 @@ Optional<HttpServerConfiguration> httpServer(BotRunner runner) {
             MetricsHandler.name(), MetricsHandler::create,
             ReadinessHandler.name(), ReadinessHandler::create,
             LivenessHandler.name(), LivenessHandler::create,
-            ProfileHandler.name(), ProfileHandler::create
+            ProfileHandler.name(), ProfileHandler::create,
+            VersionHandler.name(), VersionHandler::create
         );
         var contexts = new ArrayList<HttpContextConfiguration>();
         var port = config.get("http-server").get("port").asInt();

bot/src/main/java/org/openjdk/skara/bot/VersionHandler.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package org.openjdk.skara.bot;
+
+import org.openjdk.skara.json.JSONObject;
+import org.openjdk.skara.version.Version;
+
+import com.sun.net.httpserver.*;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.logging.Logger;
+
+class VersionHandler implements HttpHandler {
+    private static final Logger log = Logger.getLogger("org.openjdk.skara.bot");
+
+    @Override
+    public void handle(HttpExchange exchange) throws IOException {
+        var version = Version.fromManifest();
+        if (version.isPresent()) {
+            var bytes = version.get().getBytes(StandardCharsets.UTF_8);
+            exchange.sendResponseHeaders(200, bytes.length);
+            exchange.getResponseBody().write(bytes);
+            exchange.getResponseBody().close();
+        } else {
+            exchange.sendResponseHeaders(500, 0);
+            exchange.getResponseBody().close();
+        }
+    }
+
+    static VersionHandler create(BotRunner runner, JSONObject configuration) {
+        return new VersionHandler();
+    }
+
+    static String name() {
+        return "version";
+    }
+}