Log4j 2.x makes it possible to natively output logs in JSON format, without the need for additional plugins.
Example configuration
Here is a basic configuration example for outputting logs in JSON format. The presented configuration stores logs in a daily rolling file named alfresco.json, with each log statement being represented as an individually valid JSON fragment presented in a single line and separated from the next by a new line.
For more fine-grained control over the desired output, see the JSON Layout article in the Apache Log4j documentation at https://logging.apache.org/log4j. This offers an exhaustive explanation about all the properties specific to the JSON Layout that can be configured.
rootLogger.level=error
rootLogger.appenderRef.json.ref=JsonAppender
###### Daily JSON rolling file appender definition #######
appender.json.type=RollingFile
appender.json.name=JsonAppender
appender.json.fileName=alfresco.json
appender.json.filePattern=alfresco.json.%d{yyyy-MM-dd}
appender.json.layout.type=JsonLayout
appender.json.layout.eventEol=true
appender.json.layout.compact=true
appender.json.policies.type=Policies
appender.json.policies.time.type=TimeBasedTriggeringPolicy
appender.json.policies.time.interval=1
Example output
Given the configuration above, the alfresco.json file would look similar to the following:
{"instant":{"epochSecond":1669033790,"nanoOfSecond":415261100},"thread":"localhost-startStop-1","level":"INFO","loggerName":"org.springframework.extensions.webscripts.DeclarativeRegistry","message":"Registered 0 Schema Description Documents (+0 failed) ","endOfBatch":false,"loggerFqcn":"org.apache.commons.logging.impl.SLF4JLocationAwareLog","threadId":129,"threadPriority":5}
{"instant":{"epochSecond":1669033790,"nanoOfSecond":420403300},"thread":"localhost-startStop-1","level":"INFO","loggerName":"org.springframework.extensions.webscripts.AbstractRuntimeContainer","message":"Initialised Public Api Web Script Container (in 2563.5293ms)","endOfBatch":false,"loggerFqcn":"org.apache.commons.logging.impl.SLF4JLocationAwareLog","threadId":129,"threadPriority":5}
{"instant":{"epochSecond":1669033790,"nanoOfSecond":475128400},"thread":"asynchronouslyRefreshedCacheThreadPool1","level":"INFO","loggerName":"org.springframework.extensions.webscripts.DeclarativeRegistry","message":"Registered 14 Web Scripts (+0 failed), 103 URLs","endOfBatch":false,"loggerFqcn":"org.apache.commons.logging.impl.SLF4JLocationAwareLog","threadId":133,"threadPriority":5}
{"instant":{"epochSecond":1669033790,"nanoOfSecond":475128400},"thread":"asynchronouslyRefreshedCacheThreadPool1","level":"INFO","loggerName":"org.springframework.extensions.webscripts.DeclarativeRegistry","message":"Registered 0 Package Description Documents (+0 failed) ","endOfBatch":false,"loggerFqcn":"org.apache.commons.logging.impl.SLF4JLocationAwareLog","threadId":133,"threadPriority":5}
{"instant":{"epochSecond":1669033790,"nanoOfSecond":476132900},"thread":"asynchronouslyRefreshedCacheThreadPool1","level":"INFO","loggerName":"org.springframework.extensions.webscripts.DeclarativeRegistry","message":"Registered 0 Schema Description Documents (+0 failed) ","endOfBatch":false,"loggerFqcn":"org.apache.commons.logging.impl.SLF4JLocationAwareLog","threadId":133,"threadPriority":5}
{"instant":{"epochSecond":1669033819,"nanoOfSecond":711004700},"thread":"http-bio-8080-exec-1","level":"INFO","loggerName":"org.alfresco.repo.management.subsystems.ChildApplicationContextFactory","message":"Starting 'Search' subsystem, ID: [Search, managed, solr6]","endOfBatch":false,"loggerFqcn":"org.apache.commons.logging.impl.SLF4JLocationAwareLog","threadId":318,"threadPriority":5}
{"instant":{"epochSecond":1669033820,"nanoOfSecond":425889600},"thread":"http-bio-8080-exec-1","level":"INFO","loggerName":"org.alfresco.repo.management.subsystems.ChildApplicationContextFactory","message":"Startup of 'Search' subsystem, ID: [Search, managed, solr6] complete","endOfBatch":false,"loggerFqcn":"org.apache.commons.logging.impl.SLF4JLocationAwareLog","threadId":318,"threadPriority":5}
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