This Video will show you how to ensure that a service or program starts on boot on Linux. This video was recorded on CentOS 8 but the method shoudl work on most Linux Distros including Ubuntu.
The command that you need to run is:
sudo chkconfig servicename on
This command will ensure that the service starts on boot on Linux
This Java Keytool Tutorial will show you how to export a Certificate from a Java Keystore.
To begin you will first run (Note ensure that you update the relvnet commands to reflect your Keystore, alias and certificate names) :
keytool -list -keystore keystore.jks
to see what certificates reside in the java keystore.
Next you will run:
keytool -exportcert -alias domain -file domain.der -keystore keystore.jks
to export the Certificate.