Rework Docker support

- Use multi-stage build for the application image
- Utilize connection pool init timeout for waiting on database container startup,
"docker-compose-wait" dependency is no longer required
- Override database host through environment variable - used in docker-compose
- Rename database scripts for explicit ordering (db container loads them alphabetically)

.dockerignore

@@ -0,0 +1,3 @@
+/docs
+/handbook
+/tools

.gitignore

@@ -2,6 +2,7 @@
 .idea/
 *.iml
 /target
+/docker-db-data
 
 # build files
 

Dockerfile

@@ -1,13 +1,20 @@
-# Docker support, thanks to xinyifly
+# Initial Docker support thanks to xinyifly
 
-FROM openjdk:8u171-jdk-alpine
-RUN apk -U add tini
-WORKDIR /mnt
+#
+# Build stage
+#
+FROM maven:3.6.3-jdk-8 AS build
+COPY src /home/app/src
+COPY pom.xml /home/app
+RUN mvn -f /home/app/pom.xml clean package
+
+#
+# Package stage
+#
+FROM openjdk:8
+COPY --from=build /home/app/target/Cosmic.jar /usr/local/lib/Cosmic.jar
 COPY ./ ./
-RUN sh ./posix-compile.sh
-ADD https://github.com/ufoscout/docker-compose-wait/releases/download/2.6.0/wait /wait
-RUN chmod +x /wait
-
 EXPOSE 8484 7575 7576 7577
-ENTRYPOINT ["tini", "--"]
-CMD /wait && sh ./posix-launch.sh
+ENTRYPOINT ["java", "-jar", "/usr/local/lib/Cosmic.jar"]
+
+

config.yaml

@@ -162,7 +162,8 @@ server:
     USE_THREAD_TRACKER: false        #[SEVERE] This deadlock auditing thing will bloat the memory as fast as the time frame one takes to lose track of a raindrop on a tempesting day. Only for debugging purposes.
 
     #Database Configuration
-    DB_URL: "jdbc:mysql://localhost:3306/cosmic"
+    DB_URL_FORMAT: "jdbc:mysql://%s:3306/cosmic"
+    DB_HOST: "localhost"
     DB_USER: "cosmic_server"
     DB_PASS: "snailshell"
     INIT_CONNECTION_POOL_TIMEOUT: 60    # Seconds

docker-compose.yml

@@ -1,20 +1,22 @@
 version: '3'
 services:
   maplestory:
-    network_mode: "host"
     build: .
     depends_on:
       - db
+    ports:
+      - "8484:8484"
+      - "7575-7577:7575-7577"
     environment:
-      WAIT_HOSTS: localhost:3306
+      DB_HOST: "db"
     
   db:
-    network_mode: "host"
-    image: mysql:5.6
+    image: mysql:8.0.23
     environment:
-      MYSQL_ALLOW_EMPTY_PASSWORD: "yes"
+      MYSQL_RANDOM_ROOT_PASSWORD: "true"
       MYSQL_DATABASE: "cosmic"
-      MYSQL_USER: "root"
-      MYSQL_PASSWORD: ""
+      MYSQL_USER: "cosmic_server"
+      MYSQL_PASSWORD: "snailshell"
     volumes:
+      - ./docker-db-data:/var/lib/mysql
       - ./sql:/docker-entrypoint-initdb.d

src/main/java/config/ServerConfig.java

@@ -5,7 +5,8 @@ public class ServerConfig {
     public boolean USE_THREAD_TRACKER;
 
     //Database Configuration
-    public String DB_URL;
+    public String DB_URL_FORMAT;
+    public String DB_HOST;
     public String DB_USER;
     public String DB_PASS;
     public int INIT_CONNECTION_POOL_TIMEOUT;

src/main/java/tools/DatabaseConnection.java

@@ -27,10 +27,19 @@ public class DatabaseConnection {
         return dataSource.getConnection();
     }
 
+    private static String getDbUrl() {
+        // Environment variables override what's defined in the config file
+        // This feature is used for the Docker support
+        String hostOverride = System.getenv("DB_HOST");
+        String host = hostOverride != null ? hostOverride : YamlConfig.config.server.DB_HOST;
+        String dbUrl = String.format(YamlConfig.config.server.DB_URL_FORMAT, host);
+        return dbUrl;
+    }
+
     private static HikariConfig getConfig() {
         HikariConfig config = new HikariConfig();
 
-        config.setJdbcUrl(YamlConfig.config.server.DB_URL);
+        config.setJdbcUrl(getDbUrl());
         config.setUsername(YamlConfig.config.server.DB_USER);
         config.setPassword(YamlConfig.config.server.DB_PASS);