APR for Apache Tomcat on Ubuntu

apt update
apt install gcc make libapr1-dev libssl-dev
mkdir -p /system/compile
cd /system/compile

Folder to put the APR lib is /system/server/apr (you can specify any folder you like).
This example is using Tomcat 10 on Ubuntu 22.

tar -zxvf /system/server/tomcat/bin/tomcat-native.tar.gz
cd tomcat-native-2.0.5-src/native
./configure --prefix /system/server/apr --with-java-home=/system/jdk
make
make install

At this point you should see files in /system/server/apr. Now run Tomcat without APR.

export JAVA_HOME=/system/jdk
/system/server/tomcat/bin/startup.sh

Then look at/system/server/tomcat/logs/catalina.out. You probably see this. Which is expected.

08-Oct-2023 05:30:35.083 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The Apache Tomcat Native library which allows using OpenSSL was not found on the java.library.path: [/usr/java/packages/lib:/usr/lib64:/lib64:/lib:/usr/lib]

Shutdown the server first.

/system/server/tomcat/bin/shutdown.sh

Now run using CATALINA_OPTS, telling Tomcat where the APR library is installed.

export CATALINA_OPTS="-Djava.library.path=/system/server/apr/lib"
/system/server/tomcat/bin/startup.sh

Check that our CATALINA_OPTS is being read. After startup.sh you should see this.

Using CATALINA_BASE:   /system/server/tomcat
Using CATALINA_HOME:   /system/server/tomcat
Using CATALINA_TMPDIR: /system/server/tomcat/temp
Using JRE_HOME:        /system/jdk
Using CLASSPATH:       /system/server/tomcat/bin/bootstrap.jar:/system/server/tomcat/bin/tomcat-juli.jar
Using CATALINA_OPTS:   -Djava.library.path=/system/server/apr/lib
Tomcat started.

And you should be able to see /system/server/apr/lib in ps fauxgww.

# ps fauxgww
USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root        6372  3.5  9.8 2800064 95232 pts/1   Sl   05:33   0:04 /system/jdk/bin/java -Djava.util.logging.config.file=/system/server/tomcat/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources -Dorg.apache.catalina.security.SecurityListener.UMASK=0027 --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.io=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.util.concurrent=ALL-UNNAMED --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED -Djava.library.path=/system/server/apr/lib -classpath /system/server/tomcat/bin/bootstrap.jar:/system/server/tomcat/bin/tomcat-juli.jar -Dcatalina.base=/system/server/tomcat -Dcatalina.home=/system/server/tomcat -Djava.io.tmpdir=/system/server/tomcat/temp org.apache.catalina.startup.Bootstrap start

Do a tail on catalina.out again. You should expect to see this.

08-Oct-2023 05:33:42.117 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent Loaded Apache Tomcat Native library [2.0.5] using APR version [1.7.0].
08-Oct-2023 05:33:42.123 INFO [main] org.apache.catalina.core.AprLifecycleListener.initializeSSL OpenSSL successfully initialized [OpenSSL 3.0.2 15 Mar 2022]

Congratulations, you have now enabled APR on your Tomcat.