Provide a configuration option to disable transferring logging.* properties from the environment to system properties

[reda-alaoui]

Hi,

We have a Spring boot application deployed into a tomcat instance. A tomcat instance can contain multiple webapp instances.
We noticed that Spring Boot logger system was setting system properties using System.setProperty in LoggingSystemProperties. This is very bad in our case since a system property is global to the JVM and therefore to all deployed web applications.

This looks like a major bug to us.
Is there at least a way to disable LoggingApplicationListener?

[wilkinsona]

How are you configuring logging in your Spring Boot applications and which logging-related system properties are problematic?

[spring-projects-issues]

If you would like us to look at this issue, please provide the requested information. If the information is not provided within the next 7 days this issue will be closed.

[reda-alaoui]

Hi @wilkinsona ,

We use logback.

Here is what I found inside org.springframework.boot.logging.LoggingSystemProperties:

public void apply(LogFile logFile) {
		PropertyResolver resolver = getPropertyResolver();
		setSystemProperty(resolver, EXCEPTION_CONVERSION_WORD, "exception-conversion-word");
		setSystemProperty(PID_KEY, new ApplicationPid().toString());
		setSystemProperty(resolver, CONSOLE_LOG_PATTERN, "pattern.console");
		setSystemProperty(resolver, FILE_LOG_PATTERN, "pattern.file");
		setSystemProperty(resolver, FILE_CLEAN_HISTORY_ON_START, "file.clean-history-on-start");
		setSystemProperty(resolver, FILE_MAX_HISTORY, "file.max-history");
		setSystemProperty(resolver, FILE_MAX_SIZE, "file.max-size");
		setSystemProperty(resolver, FILE_TOTAL_SIZE_CAP, "file.total-size-cap");
		setSystemProperty(resolver, LOG_LEVEL_PATTERN, "pattern.level");
		setSystemProperty(resolver, LOG_DATEFORMAT_PATTERN, "pattern.dateformat");
		setSystemProperty(resolver, ROLLING_FILE_NAME_PATTERN, "pattern.rolling-file-name");
		if (logFile != null) {
			logFile.applyToSystemProperties();
		}
	}

	private PropertyResolver getPropertyResolver() {
		if (this.environment instanceof ConfigurableEnvironment) {
			PropertySourcesPropertyResolver resolver = new PropertySourcesPropertyResolver(
					((ConfigurableEnvironment) this.environment).getPropertySources());
			resolver.setIgnoreUnresolvableNestedPlaceholders(true);
			return resolver;
		}
		return this.environment;
	}

	private void setSystemProperty(PropertyResolver resolver, String systemPropertyName, String propertyName) {
		setSystemProperty(systemPropertyName, resolver.getProperty("logging." + propertyName));
	}

	private void setSystemProperty(String name, String value) {
		if (System.getProperty(name) == null && value != null) {
			System.setProperty(name, value);
		}
	}

All these values act as global values. On one Tomcat instance, we cannot configure one value per property and per Spring boot application.

[wilkinsona]

Thanks for the additional information. I asked how you were configuring logging and you didn't directly answer that. From the above, it sounds like you're using the logging.* properties to do so. This contradicts your suggestion to provide a way to disable LoggingApplicationListener as doing so would make all logging.* properties ineffective.

Given the documented behaviour of logging.* properties being transferred from the Spring environment to System properties, I don't think you should use them. You'd also have to stop using them if it was possible to disable LoggingApplicationListener and you had done so due to the becoming ineffective. Instead, I would recommend using logback.xml to configure each application's logging.

We can also consider an enhancement to disable the transfer of the logging.* properties from the Spring environment to system properties, while leaving the rest of LoggingApplicationListener's functionality intact.