Initiate Postgres connection pool on startup

src/main/java/database/PgDatabaseConnection.java

@@ -0,0 +1,28 @@
+package database;
+
+import database.note.NoteRowMapper;
+import org.jdbi.v3.core.Handle;
+import org.jdbi.v3.core.Jdbi;
+
+import javax.sql.DataSource;
+import java.sql.Connection;
+import java.sql.SQLException;
+
+public class PgDatabaseConnection {
+    private final DataSource dataSource;
+    private final Jdbi jdbi;
+
+    public PgDatabaseConnection(DataSource dataSource) {
+        this.dataSource = dataSource;
+        this.jdbi = Jdbi.create(dataSource)
+                .registerRowMapper(new NoteRowMapper()); // TODO: configure jdbi elsewhere
+    }
+
+    public Connection getConnection() throws SQLException {
+        return dataSource.getConnection();
+    }
+
+    public Handle getHandle() {
+        return jdbi.open();
+    }
+}

src/main/java/database/migration/FlywayRunner.java

@@ -4,6 +4,8 @@ import database.PgDatabaseConfig;
 import org.flywaydb.core.Flyway;
 import org.flywaydb.core.api.FlywayException;
 
+import java.util.Map;
+
 public class FlywayRunner {
     private final PgDatabaseConfig dbConfig;
 
@@ -18,6 +20,10 @@ public class FlywayRunner {
                 .createSchemas(true)
                 .connectRetries(10)
                 .connectRetriesInterval(5)
+                .placeholders(Map.of(
+                        "server-username", dbConfig.username(),
+                        "server-password", dbConfig.password())
+                )
                 .load();
         flyway.migrate();
     }

src/main/java/database/note/NoteDao.java

@@ -1,6 +1,7 @@
 package database.note;
 
 import database.DaoException;
+import database.PgDatabaseConnection;
 import model.Note;
 import org.jdbi.v3.core.Handle;
 import org.jdbi.v3.core.JdbiException;
@@ -10,6 +11,11 @@ import java.util.List;
 import java.util.Optional;
 
 public class NoteDao {
+    private final PgDatabaseConnection connection;
+
+    public NoteDao(PgDatabaseConnection connection) {
+        this.connection = connection;
+    }
 
     public void save(Note note) {
         try (Handle handle = DatabaseConnection.getHandle()) {

src/main/java/net/server/Server.java

@@ -31,6 +31,8 @@ import client.inventory.ItemFactory;
 import client.inventory.manipulator.CashIdGenerator;
 import client.newyear.NewYearCardRecord;
 import client.processor.npc.FredrickProcessor;
+import com.zaxxer.hikari.HikariConfig;
+import com.zaxxer.hikari.HikariDataSource;
 import config.ServerConfig;
 import config.YamlConfig;
 import constants.game.GameConstants;
@@ -38,6 +40,7 @@ import constants.inventory.ItemConstants;
 import constants.net.OpcodeConstants;
 import constants.net.ServerConstants;
 import database.PgDatabaseConfig;
+import database.PgDatabaseConnection;
 import database.migration.FlywayRunner;
 import database.note.NoteDao;
 import net.ChannelDependencies;
@@ -843,13 +846,15 @@ public class Server {
             Runtime.getRuntime().addShutdownHook(new Thread(shutdown(false)));
         }
 
-        runDatabaseMigration();
+        PgDatabaseConfig pgDbConfig = readPgDbConfig();
+        runDatabaseMigration(pgDbConfig);
+        PgDatabaseConnection pgDbConnection = createPgDbConnection(pgDbConfig);
 
         if (!DatabaseConnection.initializeConnectionPool()) {
             throw new IllegalStateException("Failed to initiate a connection to the database");
         }
 
-        channelDependencies = registerChannelDependencies();
+        channelDependencies = registerChannelDependencies(pgDbConnection);
 
         final ExecutorService initExecutor = Executors.newFixedThreadPool(10);
         // Run slow operations asynchronously to make startup faster
@@ -927,12 +932,6 @@ public class Server {
         }
     }
 
-    private void runDatabaseMigration() {
-        PgDatabaseConfig pgDbConfig = readPgDbConfig();
-        FlywayRunner flywayRunner = new FlywayRunner(pgDbConfig);
-        flywayRunner.migrate();
-    }
-
     private PgDatabaseConfig readPgDbConfig() {
         final ServerConfig serverConfig = YamlConfig.config.server;
         String pgDbHost = System.getenv("PG_DB_HOST");
@@ -947,8 +946,29 @@ public class Server {
         );
     }
 
-    private ChannelDependencies registerChannelDependencies() {
-        NoteService noteService = new NoteService(new NoteDao());
+    private void runDatabaseMigration(PgDatabaseConfig config) {
+        FlywayRunner flywayRunner = new FlywayRunner(config);
+        flywayRunner.migrate();
+    }
+
+    private PgDatabaseConnection createPgDbConnection(PgDatabaseConfig config) {
+        var hikariConfig = createHikariConfig(config);
+        var dataSource = new HikariDataSource(hikariConfig);
+        return new PgDatabaseConnection(dataSource);
+    }
+
+    private HikariConfig createHikariConfig(PgDatabaseConfig config) {
+        final HikariConfig hikariConfig = new HikariConfig();
+        hikariConfig.setJdbcUrl(config.getJdbcUrl());
+        hikariConfig.setSchema(config.schema());
+        hikariConfig.setUsername(config.username());
+        hikariConfig.setPassword(config.password());
+        hikariConfig.setInitializationFailTimeout(config.poolInitTimeout().toMillis());
+        return hikariConfig;
+    }
+
+    private ChannelDependencies registerChannelDependencies(PgDatabaseConnection connection) {
+        NoteService noteService = new NoteService(new NoteDao(connection));
         FredrickProcessor fredrickProcessor = new FredrickProcessor(noteService);
         ChannelDependencies channelDependencies = new ChannelDependencies(noteService, fredrickProcessor);
 

src/main/resources/db/migration/postgresql/V0.1__server_user.sql

@@ -0,0 +1,7 @@
+DO $$
+BEGIN
+    CREATE USER ${server-username} WITH PASSWORD '${server-password}';
+    EXCEPTION WHEN duplicate_object THEN RAISE NOTICE '%, skipping', SQLERRM USING ERRCODE = SQLSTATE;
+END
+$$;
+GRANT USAGE ON SCHEMA ${flyway:defaultSchema} TO ${server-username};

src/main/resources/db/migration/postgresql/V0__test.sql

@@ -1,4 +0,0 @@
-CREATE TABLE flyway_test(
-    id SERIAL PRIMARY KEY,
-    dummy TEXT
-);