setenv.sh is loaded by tomcat automatically, if it exists.

setenv.sh

#/bin/sh

# setting Variables and Environment for Tomcat
##1. server.xml docBase port

export CATALINA_HOME=/usr/local/apache-tomcat-8.5.61
export CATALINA_BASE=/usr/local/apache-tomcat-8.5.61
export CATALINA_OUT=/usr/local/apache-tomcat-8.5.61/logs/catalina.out

#export SERVER_NAME=
CATALINA_PID=$CATALINA_HOME/bin/tomcat.pid

# tomcat server.xml value setting : Connector port - http, https , Context docBase , Context path
# server.xml file

#export CATALINA_OPTS="-server $CATALINA_OPTS -Dport.http=8080 -Dport.https=443 -Dcontext.docbase=$CATALINA_BASE/webapps/civasan"

JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64

#CLASSPATH=.:$JAVA_HOME/lib/tools.jar:$CATALINA_HOME/lib-jsp-api.jar:$CATALINA_HOME/lib/servlet-api.jar #salevis.net setting
CLASSPATH=.:$CATALINA_HOME/lib/servlet-api.jar #cafe24 ai-crm setting
PATH=$PATH:$JAVA_HOME/bin:$CATALINA_HOME/bin
export JAVA_HOME CLASSPATH PATH