No logs after setting docker log driver to journald

[indykoning]

In order to save on excessive disk writes I've set my journald logger to volatile, and set /etc/docker/daemon.json log-driver to journald.

for other applications I'm getting logs with portainer and `docker compose logs" without issues.

However with this image I'm getting NO logs anymore.
Oddly enough running the container without detached mode gives me the output I expect but it still doesn't show up in the logs.

Perhaps someone else has run into it and has found a solution

[itzg]

I'm not sure why there would be anything different with this container. Logs are going to stdout just like every other image.

[indykoning]

Progress (though very little)
Disabling

    tty: false
    stdin_open: false

Gives me a single line output when shutting down

2025/09/12 19:59:10 Stopping with rcon-cli

Before or after that however, nothing....
The latest.log does have the latest logs available
It's using this log4j.xml

[itzg]

Most of the startup scripts end up just calling echo via this function.

docker-minecraft-server/scripts/start-utils

Line 120 in 9cbe5c2

echo -e "[init]${ts} $*"

The first thing that the script logs is

docker-minecraft-server/scripts/start-configuration

Line 34 in 9cbe5c2

log "Running as uid=$(id -u) gid=$(id -g) with /data as '$(ls -lnd /data)'"

You could set the env var DEBUG to "true" get more output from the shell as it's running each command.

[indykoning]

That actually gives a MASSIVE amount of output! All the way up to:

exec mc-server-runner --stop-duration 60s java -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=15 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1 -Dusing.aikars.flags=https://mcflags.emc.gs -Daikars.new.flags=true -Xmx4G -Xms1G -jar ./fabric-server-mc.1.21-loader.0.17.2-launcher.1.1.0.jar

After that it stops though.

So it seems like the echos are doing fine, but perhaps something between log4j -> docker -> journald that doesn't make it.
I'm guessing the appender for either SysOut or TerminalConsole behaves slightly different than the echos

[itzg]

After that it's executing the Minecraft server. It's beyond my control at that point.

[itzg]

...you can probably change the log4j config file used by passing "-Dlog4j.configurationFile=${file}" via the JVM_OPTS env var. You might need to contact Fabric team about what log4j config they're using by default.

[indykoning]

I've managed to get the minecraft server to log again by updating the log4j2.xml to:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN" packages="com.mojang.util">
    <Appenders>
        <!-- Console with debug info -->
        <Console name="SysOut" target="SYSTEM_OUT">
            <PatternLayout pattern="[%d{yyyy-MM-dd HH:mm:ss.SSS}] [%t/%level] [%logger]: %msg%n" />
        </Console>
        
        <!-- Error console -->
        <Console name="SysErr" target="SYSTEM_ERR">
            <PatternLayout pattern="[%d{yyyy-MM-dd HH:mm:ss.SSS}] [%t/%level] [%logger]: %msg%n" />
        </Console>
        
        <!-- Terminal Console -->
        <Queue name="TerminalConsole">
            <PatternLayout pattern="[%d{HH:mm:ss} %level]: %msg%n" />
        </Queue>
    </Appenders>
    
    <Loggers>
        <!-- Root logger - verbose -->
        <Root level="info">
            <filters>
                <MarkerFilter marker="NETWORK_PACKETS" onMatch="DENY" onMismatch="NEUTRAL" />
            </filters>
            <!-- <AppenderRef ref="SysOut"/> -->
            <AppenderRef ref="SysErr"/>
            <AppenderRef ref="TerminalConsole"/>
        </Root>
    </Loggers>
</Configuration>

as well as setting

services:
    mc-server:
        ...
        tty: false
   	    stdin_open: false
        environment:
            JVM_OPTS: "-Dlog4j.configurationFile=/data/log4j2.xml"

in the docker-compose.yml

It seems to only log SYSTEM_ERR for some reason with this container and configuration.
This sadly does mean that the helper scripts (downloading mods etc.) do not get logged.