Spring Boot - no log file written (logging.file is not respected)

Question

I use Spring Boot and want it to write log output to a file.

According to the docs, this is simply done by setting

logging.file=filename.log
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Answer 1

I had the same problem. It's more than likely due to file permissions on the file system. I had the application folder owned by root, but ./logs owned by the process owner. As such, the following didn't work:

logging.file=my.log

but this did

logging.file=/opt/myapp/logs/my.log

Answer 2

I found a solution. I am not very happy with it since it still does not answer my original question why the logging.file property is not respected.

I created the logback-spring.xml from Georges' answer in the same directory where application.properties resides. According to the documentation Spring Boot will pick it up from there. Apparently, this does not happen in my case.

I need to additionally add logging.config=classpath:logback-spring.xml in order it is picked up by Spring. The relevant parts of my application.properties are now

logging.config=classpath:logback-spring.xml
logging.file=logs/logfile.log

(I created the logs directory manually.)

Answer 3

I run my spring boot service using command line argument which works fine. All the spring boot console log writes to the file. I don't have any logging configured in my application.properties file. Spring boot version: 2.0.5.RELEASE

In windows:

java -jar target\microservice-0.0.1.jar --logging.file=C:\\logs\\microservice.log

In Linux

java -jar target\microservice-0.0.1.jar --logging.file=\var\log\microservice.log

Answer 4

In my case, I was using logging.file in the application property file.

Instead, I need to used logging.file.name, since then I can be able to get the logs into the directed path file.

Answer 5

If you are using Maven add the dependency :

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.6</version>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.5</version>
</dependency>

Now you have to specify a file that is called 'log4j.properties' which you have to put in the specific directory : ' src/main/resources/log4j.properties '

Here is how the file should look for example :

# Root logger option
log4j.rootLogger=INFO, file, stdout
log4j.logger.org.springframework.ws.client.MessageTracing.sent=TRACE
log4j.logger.org.springframework.ws.client.MessageTracing.received=TRACE

# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

# log4j.appender.springlog.Threshold=INFO
log4j.appender.springlog.layout=org.apache.log4j.PatternLayout
log4j.appender.springlog.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=D:/example/filename.log
log4j.appender.file.MaxFileSize=10MB
log4j.appender.file.MaxBackupIndex=10
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

Now import these :

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

Declare a logger variable like this :

final static Logger logger = Logger.getLogger(TheClassYourIn.class);

And use it in the class like this :

logger.info("Well hello world then ");

This way it works for me. I hope that this answer will help you . Good luck !

PS: log4j.appender.file.File='directory' is how you specify where the logs to be stored. If you don't specify a directory and just leave it as filename.log this file will be automaticly created in the project dir.

Answer 6

Sorry for the late reply. It seems spring's logger reads the property from its own classpath.Due to precedence, it's not respecting the properties supplied.

Some tricks to get around:

1. In main class set the property variable using springApplication.setDefaultProperties(properties); like this

public static void main(String[] args) {
        SpringApplication springApplication = new SpringApplication(MainClass.class);
        Properties properties = new Properties();
        properties.put("logging.file", logDirectory);
        springApplication.setDefaultProperties(properties);
        springApplication.run(args);
    }

2. Pass the property as JVM parameter -Dlogging.file=/location/output.log.

Both of the above are not the best ones as in order to define other logging properties they also should follow the same way.

Solution

Define a property file and put all you logging configurations in that and specify the file in -Dspring.config.location. This is a derivation of my other problem and this is how I resolved that. check that out in order to know other solutions that I've tried and their challenges.