Fabrified NeoForge Log4J Config

log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
	<Appenders>
		<!-- Standard output -->
		<TerminalConsole name="SysOut">
			<Select>
				<!-- If we're running through the launcher, format messages using XML -->
				<SystemPropertyArbiter propertyName="minecraft.launcher.brand" propertyValue="minecraft-launcher">
					<LegacyXMLLayout/>
				</SystemPropertyArbiter>
				<!-- Otherwise, use the vanilla format assuming it's a console -->
				<DefaultArbiter>
					<!-- Support ANSI escape sequences if we're running interactively -->
					<PatternLayout pattern="%style{[%d{HH:mm:ss}]}{blue} %highlight{[%t/%level]}{FATAL=red, ERROR=red, WARN=yellow, INFO=green, DEBUG=green, TRACE=blue} %style{(%logger{1})}{cyan} %highlight{%msg%n}{FATAL=red, ERROR=red, WARN=normal, INFO=normal, DEBUG=normal, TRACE=normal}">
						<Replace regex="\r?\n(?!\Z)" replacement="${sys:line.separator}" />
					</PatternLayout>
				</DefaultArbiter>
			</Select>
		</TerminalConsole>
		<!-- Interactive server console -->
		<Queue name="ServerGuiConsole">
			<!-- This is the same format used by the standard vanilla console -->
			<PatternLayout pattern="[%d{HH:mm:ss} %level]: %msg{nolookups}%n"/>
		</Queue>
		<!-- File logging -->
		<RollingRandomAccessFile name="File" fileName="logs/latest.log" filePattern="logs/%d{yyyy-MM-dd}-%i.log.gz">
			<!-- Strip any ANSI escape sequences if possible, and use a derivative of the vanilla format which includes the logger name -->
			<!-- TODO: it would be nice to include the mod id here too; this would likely need a custom context lookup though and may not work -->
			<PatternLayout disableAnsi="true" pattern="[%d{HH:mm:ss}] [%t/%level] [%c]: %msg{nolookups}%n"/>
			<Policies>
				<!-- Only roll over per launch of the game/server -->
				<!-- This is for ease of bug reports: users only have to upload logs/latest.log -->
				<OnStartupTriggeringPolicy/>
			</Policies>
			<!-- Only keep the past 10 logfiles to prevent logfile spam -->
			<DefaultRolloverStrategy max="10" fileIndex="min"/>
		</RollingRandomAccessFile>
	</Appenders>

	<Loggers>
		<!-- Minecraft uses isDebugEnabled() in some places to add additional debug logic, which we typically don't want enabled. -->
		<Logger name="com.mojang" level="INFO"/>
		<Logger name="net.minecraft" level="INFO"/>

		<!-- Hide class transform logging -->
		<Logger name="cpw.mods.modlauncher.ClassTransformer" level="INFO"/>

		<!-- Netty has extra requirements for modular environments which we can't yet satisfy: https://github.com/netty/netty/issues/7838 -->
		<!-- This causes errors we can't hide, as netty is not on the module boot path: https://github.com/neoforged/FancyModLoader/pull/61 -->
		<Logger name="io.netty.util.internal.PlatformDependent0">
			<Filters>
				<RegexFilter regex="^direct buffer constructor: unavailable$" onMatch="DENY" onMismatch="NEUTRAL" />
				<RegexFilter regex="^jdk\.internal\.misc\.Unsafe\.allocateUninitializedArray\(int\): unavailable$" onMatch="DENY" onMismatch="NEUTRAL" />
			</Filters>
		</Logger>

		<!-- Default logging inherited by all loggers. Users can specify loglevels for specific loggers in a composite configuration. -->
		<Root level="INFO">
			<Filters>
				<!-- Hide network packet logging a la vanilla -->
				<MarkerFilter marker="NETWORK_PACKETS" onMatch="DENY" onMismatch="NEUTRAL"/>
				<!-- Also hide our more advanced logging -->
				<MarkerFilter marker="CLASSLOADING" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="LAUNCHPLUGIN" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="CLASSDUMP" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="AXFORM" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="EVENTBUS" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="DISTXFORM" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="SCAN" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="REGISTRIES" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="REGISTRYDUMP" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="SPLASH" onMatch="DENY" onMismatch="NEUTRAL"/>
				<MarkerFilter marker="RESOURCE-CACHE" onMatch="DENY" onMismatch="NEUTRAL"/>
			</Filters>
			<AppenderRef ref="SysOut">
				<!-- Only send info and above to stdout -->
				<ThresholdFilter level="INFO"/>
			</AppenderRef>
			<!-- File logging can get everything, including debug messages, to make uploading logs easier. -->
			<AppenderRef ref="File"/>
			<!-- The server GUI console is meant to mirror stdout -->
			<AppenderRef ref="ServerGuiConsole">
				<ThresholdFilter level="INFO"/>
			</AppenderRef>
		</Root>
	</Loggers>
</Configuration>