If you watch the log as you configure the VCSA through the web management interface, you will see a series of commands calling /usr/sbin/vpxd_servicecfg. This utility is actually just a shell script wrapper for the configuration of vpxd (vCenter Server Daemon) and it's respective services.
Disclaimer: This is for educational purposes only, this is not officially supported by VMware. Please test this in a development environment before using it on actual systems.
For my lab, this was exactly what I was looking for to quickly spin up VCSA and configure all the necessary services to start the vCenter Service. In my lab, I was able to get the VCSA booted up via DHCP and execute a simple shell script remotely via SSH to VCSA and then connect to vCenter Server after the process was completed.
Here is script with the minimal commands needed for running an embedded configuration:
To run the script remotely (you do not need to copy it to VCSA), use the following command:
# ssh root@[vcsa-ip] < configureVCSA.sh
Here are some other useful commands that I tested with:
Configure Active Directory:
/usr/sbin/vpxd_servicecfg ad write [AD_USERNAME] [AD_PASSWORD] [AD_DOMAIN]
Re-initialize vCenter DB *** PLEASE BE VERY CAREFUL WHEN USING THIS COMMAND, AS DB IS WIPED***
//ensure vpxd has stopped
vpxd_servicecfg db initialize
You can also configure an external database for vCenter, NIS directory service and even replace SSL certificates but I will leave that to the reader for some exploration.