Pass runtime arguments to grails project on tomcat server - apache

Question

I'm trying to pass in a variable at runtime to my application to configure where my external config files are stored.
I need external config files so that the config can be changed without having to deploy a new release every time the config changes, and want to be able to define the location of these at run time so the applications is more portable and the team deploying the application can follow their existing rules on where to store config.
I have read answers like this:
How to add custom "-Djava" arguments to Grails app? - but I'm not sure how this relates to me from the point of having the war file on my local machine, to deploying this with the param being passed in. I have been using the Tomcat Web Application Manager to simply select the war file to upload, and clicking delpoy - the file is uploaded and automatically exploded out and launched.
https://grails.github.io/grails-doc/latest/ref/Command%20Line/war.html - This suggests that the arguments have to passed in at the point of creating the war file which is not what I'm after.
In my code I have:
grails.config.locations = ["${System.properties['configFolder']}/application-config.properties"]
and I am looking for a way to include arguments when deploying from the Application Manager, or a command something like
deploy myApp.war -DconfigFolder="/usr/share/tomcat5/.grails/myApp/conf/application-config.properties"

Answer 1

EDIT
Turns out you're meant to pass in the runtime parameters when you start the tomcat server (or just after), not when you deploy the application.
The command needed is:
export CATALINA_OPTS="-DconfigLocation=/usr/share/tomcat5/.grails/TAPaS/"
or whatever params/values you want.
This can either be entered manually once the server has been started, or you can create a setenv.sh file containing that command within the CATALINA_HOME directory. This can be found out using the echo $CATALINA_HOME. Another way to find it is to use the start command below, and view the response, e.g.
bash catalina.sh start
Using CATALINA_BASE: /opt/apache-tomcat-7.0.61
Using CATALINA_HOME: /opt/apache-tomcat-7.0.61
Using CATALINA_TMPDIR: /opt/apache-tomcat-7.0.61/temp
Using JRE_HOME: /usr
Using CLASSPATH: /opt/apache-tomcat-7.0.61/bin/bootstrap.jar:/opt/apache-tomcat-7.0.61/bin/tomcat-juli.jar
If you have added the command to the setenv.sh file, use the command bash catalina.sh start to start the server. bash catalina.sh stop is used to stop it. You will need to use the path to .sh file if you're not in the directory of them.
As far as I can work out, this is not possible.
Whenever a .war file is dropped into the appBase
if autoDeploy attribute is "true" then the application will automatically be deployed while the Tomcat server is running
else, the application will be deployed when there Tomcat server is started
bash /opt/apache-tomcat-7.0.61/bin/shutdown.sh
bash /opt/apache-tomcat-7.0.61/bin/startup.sh
will shutdown and the start up the server again and any .war files that are in the appBase will be deployed.
The only instance I can see where an actual command is needed to deploy is when using the Client Deployer Package. More information on Tomcat Deployment found at: https://tomcat.apache.org/tomcat-8.0-doc/deployer-howto.html