Use environment variables instead of server.ini by default

Dockerfile

@@ -5,7 +5,7 @@
 FROM alpine:3.20 AS base
 
 # Add OpenJDK17
-RUN apk add openjdk17=17.0.12_p7-r0
+RUN apk add --no-cache openjdk17=17.0.12_p7-r0
 
 # Uses /kepler directory
 WORKDIR /kepler
@@ -17,16 +17,16 @@ WORKDIR /kepler
 FROM base AS build
 
 # Add unzip
-RUN apk add unzip=6.0-r14
+RUN apk add --no-cache unzip=6.0-r14
 
 # Copy every files/folders that are not in .dockerignore
 COPY . .
 
 # Convert CRLF to LF executable files (failing build for Windows without this)
-RUN sed -i 's/\r$//' gradlew tools/scripts/run.sh entrypoint.sh
+RUN sed -i 's/\r$//' gradlew tools/scripts/run.sh
 
-# Make gradlew, entrypoint.sh and run.sh executable
-RUN chmod +x gradlew entrypoint.sh tools/scripts/run.sh
+# Make gradlew and run.sh executable
+RUN chmod +x gradlew tools/scripts/run.sh
 
 # Run gradle build
 RUN ./gradlew distZip
@@ -39,7 +39,6 @@ RUN rm -rf ./release/Kepler-Server/bin && \
     mkdir -p ./build/lib && \
     mv ./release/Kepler-Server/lib/Kepler-Server.jar ./build/kepler.jar && \
     mv ./release/Kepler-Server/lib/* ./build/lib && \
-    mv ./entrypoint.sh ./build/entrypoint.sh && \
     cp tools/scripts/run.sh ./build/
 
 ####################
@@ -51,6 +50,4 @@ FROM base AS production
 # Copy builded Kepler server
 COPY --from=build /kepler/build ./
 
-ENTRYPOINT [ "sh", "entrypoint.sh" ]
-
 CMD [ "sh", "run.sh" ]

Kepler-Server/src/main/java/org/alexdev/kepler/dao/Storage.java

@@ -66,7 +66,7 @@ public static boolean connect() {
 
         storage = new Storage(ServerConfiguration.getString("mysql.hostname"),
                 ServerConfiguration.getInteger("mysql.port"),
-                ServerConfiguration.getString("mysql.username"),
+                ServerConfiguration.getString("mysql.user"),
                 ServerConfiguration.getString("mysql.password"),
                 ServerConfiguration.getString("mysql.database"));
 

Kepler-Server/src/main/java/org/alexdev/kepler/util/config/ServerConfiguration.java

@@ -48,13 +48,38 @@ public static boolean getBoolean(String key) {
 
     }
 
+    /**
+     * Helper method to get value from environment variable if exists
+     * Converts the key by replacing dots with underscores and converting to uppercase 
+     * to match common environment variable naming conventions.
+     *
+     * @param key the key to use
+     * @return value from environment variable or null if not found
+     */
+    private static String getEnvOrNull(String key) {
+        String envKey = key.replace('.', '_').toUpperCase();
+        String envValue = System.getenv(envKey);
+
+        if(envValue != null && !envValue.isEmpty()) {
+            return envValue;
+        }
+
+        return null;
+    }
+
     /**
      * Get value from configuration
      *
      * @param key the key to use
      * @return value
      */
     public static String getString(String key) {
+        String envValue = getEnvOrNull(key);
+
+        if(envValue != null) {
+            return envValue;
+        }
+
         return config.getOrDefault(key, key);
     }
 
@@ -65,6 +90,12 @@ public static String getString(String key) {
      * @return value
      */
     public static String getStringOrDefault(String key, String value) {
+        String envValue = getEnvOrNull(key);
+
+        if(envValue != null) {
+            return envValue;
+        }
+
         return config.getOrDefault(key, value);
     }
 
@@ -75,6 +106,18 @@ public static String getStringOrDefault(String key, String value) {
      * @return value as int
      */
     public static int getInteger(String key) {
+        String envValue = getEnvOrNull(key);
+
+        if(envValue != null) {
+            try {
+                return Integer.parseInt(envValue);
+            } catch (NumberFormatException e) {
+                // Handle the case where the env value is not a valid integer
+                System.err.println("Environment variable for key " + key + " is not a valid integer: " + envValue);
+                // Using default value below
+            }
+        }
+
         return Integer.parseInt(config.getOrDefault(key, "0"));
     }
 

Kepler-Server/src/main/java/org/alexdev/kepler/util/config/writer/DefaultConfigWriter.java

@@ -24,7 +24,7 @@ public Map<String, String>  setConfigurationDefaults() {
 
         config.put("mysql.hostname", "127.0.0.1");
         config.put("mysql.port", "3306");
-        config.put("mysql.username", "kepler");
+        config.put("mysql.user", "kepler");
         config.put("mysql.password", "verysecret");
         config.put("mysql.database", "kepler");
 
@@ -49,7 +49,7 @@ public void setConfigurationData(Map<String, String> config, PrintWriter writer)
         writer.println("[Database]");
         writer.println("mysql.hostname=" + config.get("mysql.hostname"));
         writer.println("mysql.port=" + config.get("mysql.port"));
-        writer.println("mysql.username=" + config.get("mysql.username"));
+        writer.println("mysql.user=" + config.get("mysql.user"));
         writer.println("mysql.password=" + config.get("mysql.password"));
         writer.println("mysql.database=" + config.get("mysql.database"));
         writer.println("");