log4j2.properties cannot read variables from Docker Environment or Kubernetes Env-CodePudding

In Spring Boot 2.6.0 using Log4J2. I want to use env variables from external to log4j.propeties but it is always taking local application.propeties file instead of real docker or Kubernetes env variables

File application.properties

spring.application.name=myapp

#Logger FilePath
log.file.path=logs/dev/my-app

Docker Composer File

   version: "3"

services:
 
  spring-app-log4j2:
    build: ./log4j2
    ports:
      - "8080:80"
    environment:
      - SERVER_PORT=80
      - LOG_FILE_PATH=logs/prod/my-app

File log4j2.properties

name=config

#Read Properties values from application properties
property.filename = ${bundle:application:log.file.path}

property.layoutPattern = %d{MMM dd yyyy HH:mm:ss.SSS z} | ${hostName} | %-5p | %c{1}:%L  |  %M() - %m%n

appenders=console, rolling 

#log to console
appender.console.type=Console
appender.console.name=STDOUT
appender.console.layout.type=PatternLayout
appender.console.layout.pattern=${layoutPattern}


#log to file and daily rolling
appender.rolling.type = RollingFile
appender.rolling.name = roll
appender.rolling.fileName = ${filename}.log
appender.rolling.filePattern = ${filename}.%d{dd-MMM-yyyy}.log.gz
appender.rolling.layout.type = PatternLayout
appender.rolling.layout.pattern = ${layoutPattern}
appender.rolling.policies.type = Policies
appender.rolling.policies.time.type = TimeBasedTriggeringPolicy
appender.rolling.policies.time.interval = 2
appender.rolling.policies.time.modulate = true
appender.rolling.policies.size.type = SizeBasedTriggeringPolicy
appender.rolling.policies.size.size=100MB
appender.rolling.strategy.type = DefaultRolloverStrategy
appender.rolling.strategy.max = 5

loggers = rolling

logger.rolling.name = org.apache.logging.log4j.core.appender.rolling
logger.rolling.level = info
logger.rolling.additivity = true
logger.rolling.appenderRefs = rolling
logger.rolling.appenderRef.rolling.ref = roll


rootLogger.level=info
rootLogger.appenderRefs=stdout,rolling
rootLogger.appenderRef.stdout.ref=STDOUT
rootLogger.appenderRef.rolling.ref = roll

Output Tried

 property.filename = ${bundle:application:logpath}     #Output - logs/dev/app
    #(Taking values from application Properties only, not taking from Docker pod environment varibales)
    property.filename = ${sys:logpath}     #Output - ${sys:logpath}
    property.filename = ${env:logpath}   # Not Working   #Output - ${env:logpath}
    #use filename variable 
    appender.rolling.fileName = ${filename}.log

When Printing inside Java code

@Value("${logpath}") String logpath;  #Output -logs/prod/app
# Working with Docker env

Problem : When log4j initiated it is not finding the file path from environment , so by default reading from application.propeties

How can i read from Docker environment or Kubernetes Environment

i need log file should "logs/prod/my-app" instead of "logs/dev/my-app"

Src Code : https://github.com/jeebendu/log4j2

CodePudding user response：

In all your attempts you use a single source for the filename property. You need to use one of the fallback features of variable substitution:

You can add a default value to your variable substitution using the syntax ${variable:-default}:

property.filename = ${env:LOG_FILE_PATH:-${bundle:application:log.file.path}}
appender.rolling.fileName = ${filename}.log

or you can exploit the fact that every ${prefix:variable} falls back to ${variable}:

property.LOG_FILE_PATH = ${bundle:application:log.file.path}
appender.rolling.fileName = ${env:LOG_FILE_PATH}