I am starting to migrate an existing project from log4j1 to log4j2, i added the following maven dependencies
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-1.2-api</artifactId>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
I also deleted all logj1 jar like they say on the offical migration guide, i don't know if i have to replace all log4j.xml configuration files with log4j2.xml and change the configuration to the new syntax?
If it's the case, how i can do with third parties that use log4j and configure it with log4j.xml ?
First, there can only be a single logging configuration per application. If a third party is providing a logging configuration in a jar to be included in your app that is an issue. If it is a separate third party app then I don't understand why you are porting it from Log4j 1 to Log4j 2. That should be their problem.
Yes, your dependencies are correct. As for whether to use a log4j 1 format configuration or log4j 2 I would always recommend using the log4j 2 format if you can do the work. You can certainly try to use the log4j 1 configurations by following http://logging.apache.org/log4j/2.x/manual/compatibility.html.
Related
I've followed the doc here : https://logging.apache.org/log4j/2.x/manual/migration.html
Also looked at https://logging.apache.org/log4j/2.x/manual/configuration.html#Properties
My existing log4j.properties only uses DailyRollingFileAppender, ConsoleAppender, both of which are under the 'Supported Components', so I shouldn't be forced to convert my log4j.properties file into log4j2.properties format. I'm not accessing methods and classes internal to the Log4j 1.x implementation, as suggested by the document.
For using the bridge, I previously was using both log4j1.compatibility and log4j.configuration, but the document suggests using 'any one' (tried using just one, doesn't work)
I can build my application successfully, however, my application no longer logs anything. What am I missing?
You may want to consider reload4j as a drop-in replacement for log4j 1.x. Initiated by Ceki Gülcü, the original author of Apache log4j 1.x, the reload4j project is a fork of Apache log4j version 1.2.17 with the goal of fixing pressing security issues.
The reload4j project offers a clear and easy migration path for the users who have an urgent need to fix vulnerabilities in log4j 1.2.17.
You don't need to update your properties file.
You can add a log4j2.component.properties file on the class path (in my case, in the same directory as my log4j.properties file) to set the log4j1.compatibility property, like this:
log4j1.compatibility=true
In our case, it only required setting the compatibility property and then it automatically picked up the log4j.properties file that was available on the class path.
Figured it out.
The answer lied in the Automatic Configuration section
We need to migrate to log4j 2.17 if we are using log4j jar, mvn dependency: tree showing only log4j-over-slf4j:jar. so I assume app is safe as it will redirect call to sl4j not to log4j.
Please confirm my app is safe with this jar without any remediation.?
In the SLF4J website, in the Comments on the log4shell(CVE-2021-44228) vulnerability they state that:
If you are using log4j-over-slf4j.jar in conjunction with the SLF4J API, you are safe unless the underlying implementation is log4j 2.x.
So it basically depends on how you're implementing the logs' generation. Slf4j natively uses logback. But to be sure, you can check your pom.xml and see if log4j is mentioned there.
We are using wildfly 10 and 16 in production and a zero-day exploit exists CVE-2021-44228 for log4j for some versions.
How can I be sure that none of the code and libraries use a log4j lib that has that issue?
I do not use any log4j property file nor do I add a dependency by myself.
Any help would be greatly appreciated!
The affected log4j versions are:
Versions Affected: all log4j-core versions >=2.0-beta9 and <=2.14.1
WildFly uses log4j shaded via its log4j-jboss-logmanager module. Even the latest 1.2.2.Final version depends on log4j 1.2.17.
This means WildFly <22 is definitely not affected.
There is a log4j2-jboss-logmanager as well - but only WildFly 22+ has it. And as this doc explains:
This will be an implementation of the log4j2 API only. The core log manager for log4j2 will not be supported.
Usage of any org.apache.logging.log4j:log4j-core API’s or implementations will not be supported. In other words the log4j2 log manager implementation, including configuration files, will not be supported.
You can see that the current latest 1.0.0.Final release does not depend on log4j-core at all, only log4j-api.
So WildFly versions >=22 are not affected as well.
The official tweet confirms this.
But what about WFCORE-5743 raising the log4j-core version? Look in the pom:
<!-- This is a test only dependency -->
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>${version.org.apache.logging.log4j}</version>
<scope>test</scope>
</dependency>
It's not bundled with WildFly, only used in WildFly's build for tests.
Fixed in WildFly Core 18.0.0, to be included in WildFly 26.0.0.Final:
https://issues.redhat.com/browse/WFCORE-5743
https://issues.redhat.com/browse/WFLY-15807
If you need to use WildFly 10 or 16 in production, you should use JBoss EAP instead:
https://access.redhat.com/articles/112673#EAP_7
I'm currently working on an application which wants to dynamically change the log level of a next java application (is running on the localhost). This external application uses log4j version 1.2.16. I want to use jmx, find all "LoggerConfigAdminMBean" and change level.
In specification (visit https://logging.apache.org/log4j/2.0/manual/jmx.html) is mentioned that it is possible with the log4j 2.
Because I do not want to do much changes in the external application, so I only changed log4j1.2.16.jar by log4j1.2bridge.jar (visit https://logging.apache.org/log4j/2.x/log4j-1.2-api/index.html). But the result of this change is empty list of LoggerConfigAdminMBean.
Is the Jmx MBeans feature completely activated by using log4j 1.2 bridge jar and is there some way to get list of LoggerConfigAdminMBean full or is it possible only by migration from log4j1 to log4j2 version?
Thank you very much for the answers.
You should use these 2 dependencies:
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<version>2.11.1</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-1.2-api</artifactId>
<version>2.11.1</version>
</dependency>
And adapt log4j.properties, which must be placed in the project´s classpath. See: https://logging.apache.org/log4j/2.x/manual/configuration.html#Properties
I wrote custom log4j appender to send logs from WSO2 AM 1.10.0 to RabbitMQ. there is an exception if I add the custom appender to WSO2 AM server.
The steps of using appender:
Making a stand maven jar package which including all dependencies and put the jar file to lib folder,
Modifying log4j.properties under \repository\conf,
I am pretty sure the appender itself is working well as it has been used in a few apps to send off the logs to the queue.
Could anyone please advise me how to implement the custom log4j appender for WSO2 properly?
Thanks in advance,
Sean
It seems to be a class loading issue. I think that happens because both WSO2 server and your custom jar contain log4j classes. Set scope provided like below for slf4j dependency, and see if it works.
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.6.4</version>
<scope>provided</scope>
</dependency>