RMB-1036: Initialize loggers before setting log level

https://folio-org.atlassian.net/browse/RMB-1036

Before setting a log level for a class using PUT /admin/loglevel?level=WARN&java_package=org.folio.cql2pgjson.CQL2PgJSON we need to create the logger for that class. It may not have been used since startup.

See https://folio-org.atlassian.net/wiki/spaces/SYSOPS/pages/1407189020/RMB+log+level for details.

If multiple comma separated class names are passed each should be handled.

Author: julianladisch

domain-models-api-interfaces/ramls/admin.raml

@@ -40,7 +40,7 @@ traits:
               example: "Internal server error, contact administrator"
   /loglevel:
     put:
-      description: Set logging level for all loggers in the JVM or just for a specific package / class
+      description: Set logging level for the comma separated list of class names.  Use * as tailing wildcard to match all or specific loggers provided they have been used since startup
       is: [log-level]
       responses:
         200:

domain-models-runtime/src/main/java/org/folio/rest/tools/utils/LogUtil.java

@@ -120,26 +120,39 @@ private static String injectDeploymentId(){
 
   /**
    * Update the log level for all packages / a specific package / a specific class
-   * @param packageName - pass "*" for all packages
+   * @param packageNames - pass "*" for all packages, use comma to separate multiple names
    * @param level - see {@link Level}
    * @return - JsonObject with a list of updated loggers and their levels
    */
-  public static JsonObject updateLogConfiguration(String packageName, String level){
+  public static JsonObject updateLogConfiguration(String packageNames, String level) {
+    var updatedLoggers = new JsonObject();
+    if (packageNames == null) {
+      return updatedLoggers;
+    }
+    for (var packageName : packageNames.split(",")) {
+      updateLogConfiguration(packageName, level, updatedLoggers);
+    }
+    return updatedLoggers;
+  }
+
+  private static void updateLogConfiguration(String packageName, String level, JsonObject updatedLoggers) {
+    var prefix = packageName.replace("*", "");
+    if (prefix.equals(packageName)) {
+      // create the logger, it might not have been used since container startup
+      LogManager.getLogger(packageName);
+    }
 
-    JsonObject updatedLoggers = new JsonObject();
     LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
-    Collection<org.apache.logging.log4j.core.Logger> allLoggers = ctx.getLoggers();
 
-    allLoggers.forEach( log -> {
-      if(log != null && packageName != null && (log.getName().startsWith(packageName.replace("*", "")) || "*".equals(packageName)) ){
-        if(log != null){
-          log.setLevel(getLog4jLevel(level));
-          updatedLoggers.put(log.getName(), log.getLevel().toString());
-        }
+    for (var log: ctx.getLoggers()) {
+      if (log == null) {
+        continue;
       }
-    });
-
-    return updatedLoggers;
+      if (log.getName().startsWith(prefix)) {
+        log.setLevel(getLog4jLevel(level));
+        updatedLoggers.put(log.getName(), log.getLevel().toString());
+      }
+    }
   }
 
   /**

domain-models-runtime/src/test/java/org/folio/rest/tools/utils/LogUtilIT.java

@@ -118,4 +118,22 @@ public void append(LogEvent event) {
       message.append(event.getMessage().getFormattedMessage());
     }
   }
+
+  @Test
+  void updateLogConfigurationUnused() {
+    LogUtil.updateLogConfiguration("some.package.UnusedClass", "ERROR");
+    assertThat(LogManager.getLogger("some.package.UnusedClass").getLevel(), is(Level.ERROR));
+  }
+
+  @Test
+  void updateLogConfiguration3() {
+    LogUtil.updateLogConfiguration("foo.X,bar.Y,baz.Z", "WARN");
+    assertThat(LogManager.getLogger("foo.X").getLevel(), is(Level.WARN));
+    assertThat(LogManager.getLogger("bar.Y").getLevel(), is(Level.WARN));
+    assertThat(LogManager.getLogger("baz.Z").getLevel(), is(Level.WARN));
+    LogUtil.updateLogConfiguration("foo.*,bar.*,baz.*", "DEBUG");
+    assertThat(LogManager.getLogger("foo.X").getLevel(), is(Level.DEBUG));
+    assertThat(LogManager.getLogger("bar.Y").getLevel(), is(Level.DEBUG));
+    assertThat(LogManager.getLogger("baz.Z").getLevel(), is(Level.DEBUG));
+  }
 }