I'm looking up on the Kong API gateway and deployed a Kong instance on GKE via Google Cloud Marketplace. I want to add a custom Kong plugin to this instance and enable it for my services. How could I do it? are there any resources I could follow to get an idea on this? thank you.
You could either bake the custom plugin into your container image, or modify your Deployment manifest to download and run the plugin with command and arguments in the configuration.
For the first option, you only need to add the commands to install and run the plugin to your Dockerfile, then build an image with docker build. Once you have the new image, you can perform a rolling update by using kubectl set image deployment or modify the workload in the Cloud Console.
Modifying the Deployment YAML would have a similar result, but you would need to add command and arguments to download and run the custom plugin whenever the container starts.
The google-marketplace-kong-app and kong-dist-kubernetes repo has instructions on how to build and deploy Kong manually. I'd recommend checking them and include your custom plugin.