Add logging configuration. Add --dump option to just print the full configuration.

src/main/java/io/kamax/mxisd/config/LoggingConfig.java

@@ -0,0 +1,33 @@
+package io.kamax.mxisd.config;
+
+import org.apache.commons.lang3.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class LoggingConfig {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(LoggingConfig.class);
+
+    private String root;
+
+    public String getRoot() {
+        return root;
+    }
+
+    public void setRoot(String root) {
+        this.root = root;
+    }
+
+    public void build() {
+        String systemLevel = System.getProperty("org.slf4j.simpleLogger.log.io.kamax.mxisd");
+        LOGGER.info("Logging config:");
+        if (StringUtils.isNotBlank(systemLevel)) {
+            LOGGER.info("  Logging level set by environment: {}", systemLevel);
+        } else if (StringUtils.isNotBlank(getRoot())) {
+            LOGGER.info("  Logging level set by the configuration: {}", getRoot());
+            System.setProperty("org.slf4j.simpleLogger.log.io.kamax.mxisd", getRoot());
+        } else {
+            LOGGER.info("  Logging level hasn't set, use default");
+        }
+    }
+}

src/main/java/io/kamax/mxisd/config/MxisdConfig.java

@@ -117,6 +117,7 @@ public class MxisdConfig {
     private WordpressConfig wordpress = new WordpressConfig();
     private PolicyConfig policy = new PolicyConfig();
     private HashingConfig hashing = new HashingConfig();
+    private LoggingConfig logging = new LoggingConfig();
 
     public AppServiceConfig getAppsvc() {
         return appsvc;
@@ -342,6 +343,14 @@ public class MxisdConfig {
         this.hashing = hashing;
     }
 
+    public LoggingConfig getLogging() {
+        return logging;
+    }
+
+    public void setLogging(LoggingConfig logging) {
+        this.logging = logging;
+    }
+
     public MxisdConfig inMemory() {
         getKey().setPath(":memory:");
         getStorage().getProvider().getSqlite().setDatabase(":memory:");
@@ -350,6 +359,8 @@ public class MxisdConfig {
     }
 
     public MxisdConfig build() {
+        getLogging().build();
+
         if (StringUtils.isBlank(getServer().getName())) {
             getServer().setName(getMatrix().getDomain());
             log.debug("server.name is empty, using matrix.domain");

src/main/java/io/kamax/mxisd/config/YamlConfigLoader.java

@@ -76,4 +76,14 @@ public class YamlConfigLoader {
         }
     }
 
+    public static void dumpConfig(MxisdConfig cfg) {
+        Representer rep = new Representer();
+        rep.getPropertyUtils().setBeanAccess(BeanAccess.FIELD);
+        rep.getPropertyUtils().setAllowReadOnlyProperties(true);
+        rep.getPropertyUtils().setSkipMissingProperties(true);
+
+        Yaml yaml = new Yaml(new Constructor(MxisdConfig.class), rep);
+        String dump = yaml.dump(cfg);
+        log.info("Full configuration:\n{}", dump);
+    }
 }