Is there an alternative way in GCP that emulates or somehow replicates the functionality of Cloud Armor? I'm trying to create a setup that is somehow secured against DDoS but more cost effective as this is only a test run. I'm open to recommendations or if someone can drop a documentation that I can follow would be great as I am new to GCP and I'm still exploring. Many thanks in advance.
Haven't done anything yet and still planning
You can deploy third-party DDoS protection solutions
In order to meet your specific needs of protection for DDoS attack prevention/mitigation, consider purchasing specialized third-party DDoS protection solutions to protect against such attacks.
You could easily deploy and manage popular 3rd party DDos tools such as DDoS radar, FastNetMon Advanced, Imperva Incapsula from the Cloud Marketplace.
You can also refer refer to Best Practices for DDoS Protection and Mitigation on Google Cloud Platform for additional information.