Add healthcheck for standalone app

standalone/app/src/main/java/me/lucko/luckperms/standalone/app/LuckPermsApplication.java

@@ -26,9 +26,11 @@
 package me.lucko.luckperms.standalone.app;
 
 import me.lucko.luckperms.standalone.app.integration.CommandExecutor;
-import me.lucko.luckperms.standalone.app.integration.DockerCommandSocket;
+import me.lucko.luckperms.standalone.app.integration.HealthReporter;
 import me.lucko.luckperms.standalone.app.integration.ShutdownCallback;
-import me.lucko.luckperms.standalone.app.integration.TerminalInterface;
+import me.lucko.luckperms.standalone.app.utils.DockerCommandSocket;
+import me.lucko.luckperms.standalone.app.utils.HeartbeatHttpServer;
+import me.lucko.luckperms.standalone.app.utils.TerminalInterface;
 
 import net.luckperms.api.LuckPerms;
 
@@ -55,12 +57,16 @@ public class LuckPermsApplication implements AutoCloseable {
     private LuckPerms luckPermsApi;
     /** A command executor interface to run LuckPerms commands */
     private CommandExecutor commandExecutor;
+    /** An interface that can poll the health of the application */
+    private HealthReporter healthReporter;
 
     /** If the application is running */
     private final AtomicBoolean running = new AtomicBoolean(true);
 
     /** The docker command socket */
     private DockerCommandSocket dockerCommandSocket;
+    /** The heartbeat http server */
+    private HeartbeatHttpServer heartbeatHttpServer;
 
     public LuckPermsApplication(ShutdownCallback shutdownCallback) {
         this.shutdownCallback = shutdownCallback;
@@ -75,6 +81,7 @@ public class LuckPermsApplication implements AutoCloseable {
         List<String> arguments = Arrays.asList(args);
         if (arguments.contains("--docker")) {
             this.dockerCommandSocket = DockerCommandSocket.createAndStart(3000, terminal);
+            this.heartbeatHttpServer = HeartbeatHttpServer.createAndStart(3001, this.healthReporter);
         }
 
         terminal.start(); // blocking
@@ -95,6 +102,14 @@ public class LuckPermsApplication implements AutoCloseable {
                 LOGGER.warn(e);
             }
         }
+
+        if (this.heartbeatHttpServer != null) {
+            try {
+                this.heartbeatHttpServer.close();
+            } catch (Exception e) {
+                LOGGER.warn(e);
+            }
+        }
     }
 
     public AtomicBoolean runningState() {
@@ -111,6 +126,11 @@ public class LuckPermsApplication implements AutoCloseable {
         this.commandExecutor = commandExecutor;
     }
 
+    // called before start()
+    public void setHealthReporter(HealthReporter healthReporter) {
+        this.healthReporter = healthReporter;
+    }
+
     public String getVersion() {
         return "@version@";
     }

standalone/app/src/main/java/me/lucko/luckperms/standalone/app/integration/HealthReporter.java

@@ -0,0 +1,77 @@
+/*
+ * This file is part of LuckPerms, licensed under the MIT License.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.standalone.app.integration;
+
+import com.google.gson.Gson;
+
+import java.util.Map;
+
+/**
+ * An interface able to provide information about the application/plugin health.
+ */
+public interface HealthReporter {
+
+    /**
+     * Polls the current health status.
+     *
+     * @return the health status
+     */
+    Health poll();
+
+    final class Health {
+        private static final Gson GSON = new Gson();
+
+        private final boolean up;
+        private final Map<String, String> details;
+
+        Health(boolean up, Map<String, String> details) {
+            this.up = up;
+            this.details = details;
+        }
+
+        public boolean isUp() {
+            return this.up;
+        }
+
+        public Map<String, String> details() {
+            return this.details;
+        }
+
+        @Override
+        public String toString() {
+            return GSON.toJson(this);
+        }
+
+        public static Health up(Map<String, String> details) {
+            return new Health(true, details);
+        }
+
+        public static Health down(Map<String, String> details) {
+            return new Health(false, details);
+        }
+    }
+
+}

standalone/app/src/main/java/me/lucko/luckperms/standalone/app/utils/DockerCommandSocket.java

@@ -23,7 +23,7 @@
  *  SOFTWARE.
  */
 
-package me.lucko.luckperms.standalone.app.integration;
+package me.lucko.luckperms.standalone.app.utils;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -56,7 +56,7 @@ public class DockerCommandSocket extends ServerSocket implements Runnable {
             thread.setDaemon(true);
             thread.start();
 
-            LOGGER.info("Created Docker command socket on port 3000");
+            LOGGER.info("Created Docker command socket on port " + port);
         } catch (Exception e) {
             LOGGER.error("Error starting docker command socket", e);
         }

standalone/app/src/main/java/me/lucko/luckperms/standalone/app/utils/HeartbeatHttpServer.java

@@ -0,0 +1,96 @@
+/*
+ * This file is part of LuckPerms, licensed under the MIT License.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.standalone.app.utils;
+
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpHandler;
+import com.sun.net.httpserver.HttpServer;
+
+import me.lucko.luckperms.standalone.app.integration.HealthReporter;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.InetSocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+/**
+ * Provides a tiny http server indicating the current status of the app
+ */
+public class HeartbeatHttpServer implements HttpHandler, AutoCloseable {
+    private static final Logger LOGGER = LogManager.getLogger(HeartbeatHttpServer.class);
+
+    private static final ExecutorService EXECUTOR = Executors.newCachedThreadPool(new ThreadFactoryBuilder()
+            .setDaemon(true)
+            .setNameFormat("heartbeat-http-server-%d")
+            .build()
+    );
+
+    public static HeartbeatHttpServer createAndStart(int port, HealthReporter healthReporter) {
+        HeartbeatHttpServer socket = null;
+
+        try {
+            socket = new HeartbeatHttpServer(healthReporter, port);
+            LOGGER.info("Created Heartbeat HTTP server on port " + port);
+        } catch (Exception e) {
+            LOGGER.error("Error starting Heartbeat HTTP server", e);
+        }
+
+        return socket;
+    }
+
+    private final HealthReporter healthReporter;
+    private final HttpServer server;
+
+    public HeartbeatHttpServer(HealthReporter healthReporter, int port) throws IOException {
+        this.healthReporter = healthReporter;
+        this.server = HttpServer.create(new InetSocketAddress(port), 50);
+        this.server.createContext("/health", this);
+        this.server.setExecutor(EXECUTOR);
+        this.server.start();
+    }
+
+    @Override
+    public void handle(HttpExchange exchange) throws IOException {
+        HealthReporter.Health health = this.healthReporter.poll();
+        byte[] response = health.toString().getBytes(StandardCharsets.UTF_8);
+
+        exchange.sendResponseHeaders(health.isUp() ? 200 : 503, response.length);
+        try (OutputStream responseBody = exchange.getResponseBody()) {
+            responseBody.write(response);
+        }
+    }
+
+    @Override
+    public void close() {
+        this.server.stop(0);
+    }
+}

standalone/app/src/main/java/me/lucko/luckperms/standalone/app/utils/TerminalInterface.java

@@ -23,9 +23,10 @@
  *  SOFTWARE.
  */
 
-package me.lucko.luckperms.standalone.app.integration;
+package me.lucko.luckperms.standalone.app.utils;
 
 import me.lucko.luckperms.standalone.app.LuckPermsApplication;
+import me.lucko.luckperms.standalone.app.integration.CommandExecutor;
 
 import net.minecrell.terminalconsole.SimpleTerminalConsole;
 

standalone/docker/Dockerfile

@@ -20,3 +20,6 @@ RUN mkdir data
 VOLUME ["/opt/luckperms/data"]
 
 CMD ["java", "-jar", "luckperms-standalone.jar", "--docker"]
+
+HEALTHCHECK --interval=30s --timeout=15s --start-period=20s \
+    CMD wget http://localhost:3001/health -q -O - | grep -c '"up":true' || exit 1

standalone/src/main/java/me/lucko/luckperms/standalone/LPStandalonePlugin.java

@@ -38,11 +38,11 @@ import me.lucko.luckperms.common.model.manager.user.StandardUserManager;
 import me.lucko.luckperms.common.plugin.AbstractLuckPermsPlugin;
 import me.lucko.luckperms.common.plugin.util.AbstractConnectionListener;
 import me.lucko.luckperms.common.sender.Sender;
-import me.lucko.luckperms.standalone.app.integration.SingletonPlayer;
 import me.lucko.luckperms.standalone.app.LuckPermsApplication;
-import me.lucko.luckperms.standalone.dummy.StandaloneContextManager;
-import me.lucko.luckperms.standalone.dummy.StandaloneDummyConnectionListener;
-import me.lucko.luckperms.standalone.dummy.StandaloneEventBus;
+import me.lucko.luckperms.standalone.app.integration.SingletonPlayer;
+import me.lucko.luckperms.standalone.stub.StandaloneContextManager;
+import me.lucko.luckperms.standalone.stub.StandaloneDummyConnectionListener;
+import me.lucko.luckperms.standalone.stub.StandaloneEventBus;
 
 import net.luckperms.api.LuckPerms;
 import net.luckperms.api.query.QueryOptions;
@@ -57,6 +57,8 @@ import java.util.stream.Stream;
 public class LPStandalonePlugin extends AbstractLuckPermsPlugin {
     private final LPStandaloneBootstrap bootstrap;
 
+    private boolean running = false;
+
     private StandaloneSenderFactory senderFactory;
     private StandaloneDummyConnectionListener connectionListener;
     private StandaloneCommandManager commandManager;
@@ -78,6 +80,10 @@ public class LPStandalonePlugin extends AbstractLuckPermsPlugin {
         return this.bootstrap.getLoader();
     }
 
+    public boolean isRunning() {
+        return this.running;
+    }
+
     @Override
     protected void setupSenderFactory() {
         this.senderFactory = new StandaloneSenderFactory(this);
@@ -144,16 +150,17 @@ public class LPStandalonePlugin extends AbstractLuckPermsPlugin {
     @Override
     protected void registerApiOnPlatform(LuckPerms api) {
         this.bootstrap.getLoader().setApi(api);
+        this.bootstrap.getLoader().setHealthReporter(new StandaloneHealthReporter(this));
     }
 
     @Override
     protected void performFinalSetup() {
-
+        this.running = true;
     }
 
     @Override
     protected void removePlatformHooks() {
-
+        this.running = false;
     }
 
     @Override

standalone/src/main/java/me/lucko/luckperms/standalone/StandaloneHealthReporter.java

@@ -0,0 +1,70 @@
+/*
+ * This file is part of LuckPerms, licensed under the MIT License.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.standalone;
+
+import me.lucko.luckperms.common.locale.TranslationManager;
+import me.lucko.luckperms.standalone.app.integration.HealthReporter;
+
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.plain.PlainTextComponentSerializer;
+
+import java.util.Collections;
+import java.util.Locale;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public class StandaloneHealthReporter implements HealthReporter {
+    private final LPStandalonePlugin plugin;
+
+    public StandaloneHealthReporter(LPStandalonePlugin plugin) {
+        this.plugin = plugin;
+    }
+
+    @Override
+    public Health poll() {
+        if (!this.plugin.isRunning()) {
+            return Health.down(Collections.emptyMap());
+        }
+
+        Map<String, String> meta = this.plugin.getStorage().getMeta().entrySet().stream()
+                .collect(Collectors.toMap(
+                        e -> render(e.getKey()).toLowerCase(Locale.ROOT),
+                        e -> render(e.getValue())
+                ));
+
+        if ("false".equals(meta.get("connected"))) {
+            return Health.down(Collections.singletonMap("reason", "storage disconnected"));
+        }
+
+        return Health.up(meta);
+    }
+
+    private static String render(Component component) {
+        return PlainTextComponentSerializer.plainText().serialize(
+                TranslationManager.render(component)
+        );
+    }
+}

standalone/src/main/java/me/lucko/luckperms/standalone/stub/StandaloneContextManager.java

@@ -23,7 +23,7 @@
  *  SOFTWARE.
  */
 
-package me.lucko.luckperms.standalone.dummy;
+package me.lucko.luckperms.standalone.stub;
 
 import me.lucko.luckperms.common.config.ConfigKeys;
 import me.lucko.luckperms.common.context.manager.ContextManager;

standalone/src/main/java/me/lucko/luckperms/standalone/stub/StandaloneDummyConnectionListener.java

@@ -23,7 +23,7 @@
  *  SOFTWARE.
  */
 
-package me.lucko.luckperms.standalone.dummy;
+package me.lucko.luckperms.standalone.stub;
 
 import me.lucko.luckperms.common.plugin.LuckPermsPlugin;
 import me.lucko.luckperms.common.plugin.util.AbstractConnectionListener;

standalone/src/main/java/me/lucko/luckperms/standalone/stub/StandaloneEventBus.java

@@ -23,7 +23,7 @@
  *  SOFTWARE.
  */
 
-package me.lucko.luckperms.standalone.dummy;
+package me.lucko.luckperms.standalone.stub;
 
 import me.lucko.luckperms.common.api.LuckPermsApiProvider;
 import me.lucko.luckperms.common.event.AbstractEventBus;