must build default json config with default values (#540)

src/main/java/com/mageddo/dnsproxyserver/config/dataprovider/ConfigDAOJson.java

@@ -2,16 +2,13 @@
 
 import com.mageddo.dnsproxyserver.config.Config;
 import com.mageddo.dnsproxyserver.config.dataprovider.mapper.ConfigJsonV2Mapper;
-import com.mageddo.utils.Files;
-import com.mageddo.utils.Runtime;
 import com.mageddo.utils.Tests;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
 import javax.inject.Inject;
 import javax.inject.Singleton;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.Arrays;
 
 @Slf4j
@@ -26,7 +23,7 @@ public class ConfigDAOJson implements ConfigDAO {
   public Config find() {
     final var workDir = this.configDAOEnv.findRaw().getCurrentPath();
     final var relativeConfigFilePath = this.configDAOCmdArgs.findRaw().getConfigPath();
-    final var configFileAbsolutePath = buildConfigPath(workDir, relativeConfigFilePath);
+    final var configFileAbsolutePath = ConfigPathBuilder.build(workDir, relativeConfigFilePath);
     return this.find(configFileAbsolutePath);
   }
 
@@ -36,27 +33,6 @@ public Config find(Path configPath) {
     return ConfigJsonV2Mapper.toConfig(jsonConfig, configPath);
   }
 
-  public static Path buildConfigPath(Path workDir, String configPath) {
-    if (runningInTestsAndNoCustomConfigPath()) {
-      return Files.createTempFileDeleteOnExit("dns-proxy-server-junit", ".json");
-    }
-    if (workDir != null) {
-      return workDir
-        .resolve(configPath)
-        .toAbsolutePath()
-        ;
-    }
-    final var confRelativeToCurrDir = Paths
-      .get(configPath)
-      .toAbsolutePath();
-    if (Files.exists(confRelativeToCurrDir)) {
-      return confRelativeToCurrDir;
-    }
-    return Runtime.getRunningDir()
-      .resolve(configPath)
-      .toAbsolutePath();
-  }
-
   static boolean runningInTestsAndNoCustomConfigPath() {
     return !Arrays.toString(ConfigDAOCmdArgs.getArgs()).contains("--conf-path") && Tests.inTest();
   }

src/main/java/com/mageddo/dnsproxyserver/config/dataprovider/ConfigPathBuilder.java

@@ -0,0 +1,40 @@
+package com.mageddo.dnsproxyserver.config.dataprovider;
+
+import com.mageddo.utils.Files;
+import com.mageddo.utils.Runtime;
+import lombok.extern.slf4j.Slf4j;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+@Slf4j
+public class ConfigPathBuilder {
+  private static Path build0(Path workDir, String configPath) {
+    if (ConfigDAOJson.runningInTestsAndNoCustomConfigPath()) {
+      final var file = Files.createTempFileDeleteOnExit("dns-proxy-server-junit", ".json");
+      log.trace("status=runningInTests, usingEmptyFile={}", file);
+      return file;
+    }
+    if (workDir != null) {
+      return workDir
+        .resolve(configPath)
+        .toAbsolutePath()
+        ;
+    }
+    final var confRelativeToCurrDir = Paths
+      .get(configPath)
+      .toAbsolutePath();
+    if (Files.exists(confRelativeToCurrDir)) {
+      return confRelativeToCurrDir;
+    }
+    return Runtime.getRunningDir()
+      .resolve(configPath)
+      .toAbsolutePath();
+  }
+
+  public static Path build(Path workDir, String relativeConfigFilePath) {
+    final var path = build0(workDir, relativeConfigFilePath);
+    log.debug("status=configPathBuilt, path={}", path);
+    return path;
+  }
+}

src/main/java/com/mageddo/dnsproxyserver/config/dataprovider/JsonConfigs.java

@@ -15,7 +15,6 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 
@@ -35,7 +34,7 @@ public class JsonConfigs {
   public static ConfigJson loadConfig(Path configPath) {
 
     if (!Files.exists(configPath)) {
-      createDefault(configPath);
+      createDefaultConfigOnPath(configPath);
     }
 
     return loadConfig(Files.readString(configPath));
@@ -48,7 +47,7 @@ public static ConfigJson loadConfig(String jsonContent) {
     final var tree = objectMapper.readTree(jsonContent);
     if (tree.isEmpty()) {
       log.info("status=emptyConfigFile, action=usingDefault");
-      return new ConfigJsonV2();
+      return JsonConfigs.buildDefaultJsonConfig();
     }
     final var version = findVersion(tree);
     return switch (version) {
@@ -61,23 +60,25 @@ public static ConfigJson loadConfig(String jsonContent) {
   }
 
   @SneakyThrows
-  static void createDefault(Path configPath) {
-    final var config = new ConfigJsonV2();
-
+  static void createDefaultConfigOnPath(Path configPath) {
     Files.createDirectories(configPath.getParent()); // ensure directories are created
+    final var config = buildDefaultJsonConfig();
+    JsonUtils
+      .prettyInstance()
+      .writeValue(configPath.toFile(), config);
+    log.info("status=createdDefaultConfigFile, path={}", configPath);
+  }
 
+  public static ConfigJsonV2 buildDefaultJsonConfig() {
+    final var config = new ConfigJsonV2();
     config
       .get_envs()
       .add(
         new Env()
           .setName(Config.Env.DEFAULT_ENV)
-          .setHostnames(Collections.singletonList(Entry.sample()))
+          .add(Entry.sample())
       );
-
-    JsonUtils
-      .prettyInstance()
-      .writeValue(configPath.toFile(), config);
-    log.info("status=createdDefaultConfigFile, path={}", configPath);
+    return config;
   }
 
   @SneakyThrows

src/test/java/com/mageddo/dnsproxyserver/config/dataprovider/ConfigDAOJsonTest.java

@@ -36,7 +36,7 @@ void mustBuildConfPathRelativeToWorkDir(@TempDir Path tmpDir){
     ConfigDAOCmdArgs.setArgs(flags.getArgs());
 
     // act
-    final var configPath = ConfigDAOJson.buildConfigPath(workDir, flags.getConfigPath());
+    final var configPath = ConfigPathBuilder.build(workDir, flags.getConfigPath());
 
     // assert
     assertEquals("config.json", configPath.getFileName().toString());