Set environment variable in shell script/access in Tomcat Application

Question

I want to add and environment variable which can access by my tomcat web-app. I have gone through this link but i want to set environment variable in root user. How to do that?

Answer 1

According to the docs (http://tomcat.apache.org/tomcat-7.0-doc/RUNNING.txt) you should set all env vars in $CATALINA_HOME/bin/setenv.sh

EDIT: For completeness, I guess it's worth mentioning that even though this is the recommended way, the docs above state that:

By default the setenv script file is absent. If the script file is present both in CATALINA_BASE and in CATALINA_HOME, the one in CATALINA_BASE is preferred.

In case it is absent, you might also want to look for env vars in:

• /etc/tomcat/tomcat[67].conf (suse) or
• /etc/default/tomcat[67].conf (e.g. ubuntu) or
• /etc/sysconfig/tomcat[67].conf (rhel, fedora)

Answer 2

This is how you can do it

1. sudo su and cd to /var/lib/tomcat8/bin/ (or whichever is your tomcat bin path)
2. touch setenv.sh(if it doesn't exist), if file present already do 'vi setenv.sh'
3. chmod 777 setenv.sh (make file executable)
4. vi setenv.sh and set following line in setenv.sh export key=value
5. sudo systemctl restart tomcat.service

In your java file you can use the following code to check if the variable is set

private static void printEnv() {
    System.out.println("******************************Environment Vars*****************************");
    Map<String, String> enviorntmentVars = System.getenv();
    enviorntmentVars.entrySet().forEach(System.out::println);

    System.out.println("******************************system Vars*****************************");
    Properties enviorntmentProperties = System.getProperties();
    enviorntmentVars.entrySet().forEach(System.out::println);
}