如何在 log4j2.xml 中配置 Log4J2 Kubernetes 支持

Question

I want to use the log4j2 Kubernetes Support to send my logs and information about the pod with fluent bit to ElasticSearch. According to https://logging.apache.org/log4j/2.x/log4j-kubernetes/index.html there are some configuration values to be set. In my case I have to set log4j2.kubernetes.client.namespace, but I didn't managed to set the property correct.

in my current version of log4j2.xml I've set nearly every variant I could imagine:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <Properties>
        <Property name="log4j2.kubernetes.client.namespace">app-dev</Property>
        <Property name="kubernetes.client.namespace">app-dev</Property>
        <Property name="client.namespace">app-dev</Property>
        <Property name="log4j2_kubernetes_client_namespace">app-dev</Property>
        <Property name="kubernetes_client_namespace">app-dev</Property>
        <Property name="client_namespace">app-dev</Property>
        <Property name="namespace">app-dev</Property>
    </Properties>
    <Appenders>
        <Console name="Console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
        </Console>
        <Socket name="Elastic" host="fluent-bit" port="2020" protocol="tcp" bufferedIo="true">
            <JsonLayout includeStackTrace="true" includeNullDelimiter="true">
                <KeyValuePair key="containerId" value="${docker:containerId:-}"/>
                <KeyValuePair key="application" value="$${lower:${spring:spring.application.name}}"/>
                <KeyValuePair key="kubernetes.serviceAccountName" value="${k8s:accountName:-}"/>
                <KeyValuePair key="kubernetes.containerId" value="${k8s:containerId:-}"/>
                <KeyValuePair key="kubernetes.containerName" value="${k8s:containerName:-}"/>
                <KeyValuePair key="kubernetes.host" value="${k8s:host:-}"/>
                <KeyValuePair key="kubernetes.labels.app" value="${k8s:labels.app:-}"/>
                <KeyValuePair key="kubernetes.labels.pod-template-hash" value="${k8s:labels.podTemplateHash:-}"/>
                <KeyValuePair key="kubernetes.master_url" value="${k8s:masterUrl:-}"/>
                <KeyValuePair key="kubernetes.namespaceId" value="${k8s:namespaceId:-}"/>
                <KeyValuePair key="kubernetes.namespaceName" value="${k8s:namespaceName:-}"/>
                <KeyValuePair key="kubernetes.podID" value="${k8s:podId:-}"/>
                <KeyValuePair key="kubernetes.podIP" value="${k8s:podIp:-}"/>
                <KeyValuePair key="kubernetes.podName" value="${k8s:podName:-}"/>
                <KeyValuePair key="kubernetes.imageId" value="${k8s:imageId:-}"/>
                <KeyValuePair key="kubernetes.imageName" value="${k8s:imageName:-}"/>
            </JsonLayout>
        </Socket>
    </Appenders>
    <Loggers>
        <Logger name="xx.xxx.xxxx" level="info" additivity="false">
            <AppenderRef ref="Elastic"/>
            <AppenderRef ref="Console"/>
        </Logger>

        <Root level="info">
            <AppenderRef ref="Elastic"/>
            <AppenderRef ref="Console"/>
        </Root>
    </Loggers>
</Configuration>

The Stacktrace I get when the pod starts:

Exception in thread "main" java.lang.NoSuchMethodError: 'java.lang.String org.apache.logging.log4j.util.PropertiesUtil.getStringProperty(java.lang.String[], java.lang.String, org.apache.logging.log4j.util.Supplier)'
    at org.apache.logging.log4j.kubernetes.KubernetesClientProperties.getApiVersion(KubernetesClientProperties.java:66)
    at org.apache.logging.log4j.kubernetes.KubernetesClientBuilder.kubernetesClientConfig(KubernetesClientBuilder.java:42)
    at org.apache.logging.log4j.kubernetes.KubernetesClientBuilder.createClient(KubernetesClientBuilder.java:35)
    at org.apache.logging.log4j.kubernetes.KubernetesLookup.initialize(KubernetesLookup.java:67)
    at org.apache.logging.log4j.kubernetes.KubernetesLookup.lookup(KubernetesLookup.java:115)
    at org.apache.logging.log4j.core.lookup.AbstractLookup.lookup(AbstractLookup.java:33)
    at org.apache.logging.log4j.core.lookup.Interpolator.lookup(Interpolator.java:198)
    at org.apache.logging.log4j.core.lookup.StrSubstitutor.resolveVariable(StrSubstitutor.java:1060)
    at org.apache.logging.log4j.core.lookup.StrSubstitutor.substitute(StrSubstitutor.java:982)
    at org.apache.logging.log4j.core.lookup.StrSubstitutor.substitute(StrSubstitutor.java:878)
    at org.apache.logging.log4j.core.lookup.StrSubstitutor.replace(StrSubstitutor.java:433)
    at org.apache.logging.log4j.core.config.plugins.visitors.PluginBuilderAttributeVisitor.visit(PluginBuilderAttributeVisitor.java:49)
    at org.apache.logging.log4j.core.config.plugins.util.PluginBuilder.injectFields(PluginBuilder.java:185)
    at org.apache.logging.log4j.core.config.plugins.util.PluginBuilder.build(PluginBuilder.java:121)
    at org.apache.logging.log4j.core.config.AbstractConfiguration.createPluginObject(AbstractConfiguration.java:1002)
    at org.apache.logging.log4j.core.config.AbstractConfiguration.createConfiguration(AbstractConfiguration.java:942)
    at org.apache.logging.log4j.core.config.AbstractConfiguration.createConfiguration(AbstractConfiguration.java:934)
    at org.apache.logging.log4j.core.config.AbstractConfiguration.createConfiguration(AbstractConfiguration.java:934)
    at org.apache.logging.log4j.core.config.AbstractConfiguration.createConfiguration(AbstractConfiguration.java:934)
    at org.apache.logging.log4j.core.config.AbstractConfiguration.doConfigure(AbstractConfiguration.java:552)
    at org.apache.logging.log4j.core.config.AbstractConfiguration.initialize(AbstractConfiguration.java:241)
    at org.apache.logging.log4j.core.config.AbstractConfiguration.start(AbstractConfiguration.java:288)
    at org.apache.logging.log4j.core.LoggerContext.setConfiguration(LoggerContext.java:579)
    at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:651)
    at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:668)
    at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:253)
    at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:153)
    at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:45)
    at org.apache.logging.log4j.LogManager.getContext(LogManager.java:194)
    at org.apache.logging.log4j.spi.AbstractLoggerAdapter.getContext(AbstractLoggerAdapter.java:138)
    at org.apache.logging.slf4j.Log4jLoggerFactory.getContext(Log4jLoggerFactory.java:45)
    at org.apache.logging.log4j.spi.AbstractLoggerAdapter.getLogger(AbstractLoggerAdapter.java:48)
    at org.apache.logging.slf4j.Log4jLoggerFactory.getLogger(Log4jLoggerFactory.java:30)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:363)
    at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:388)

Log4j2 part of my pom.xml:

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-log4j2</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.13.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-slf4j-impl</artifactId>
            <version>2.13.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-jul</artifactId>
            <version>2.13.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>2.13.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-kubernetes</artifactId>
            <version>2.13.2</version>
        </dependency>
        <dependency>
            <groupId>io.fabric8</groupId>
            <artifactId>kubernetes-client</artifactId>
            <version>4.4.1</version>
        </dependency>

How can I set the property correct or can I set it as an enviroment variable / jvm argument to be more flexible with different namespaces? (Alternatively I would create a config map with the file)

Answer 1

You are getting a NoSuchMethodError. The method that is being called was added in Log4j 2.13.0. This means that somehow you are getting a version of org.apache.logging.log4j.util.PropertiesUtil from a release earlier than that. You need to check all your jars to make sure you don't somehow have 2 versions of that on the classpath.