kustomize:tldr:ad2a8

This command performs two operations:

1. kustomize build .: This command uses kustomize tool to build the configuration based on the files and directories present in the current directory (.). kustomize is a configuration management tool that allows you to generate customized Kubernetes manifests dynamically.

2. | kubectl apply -f -: The vertical bar | is a pipe operator that is used to redirect the output of the previous command to the next command. In this case, it redirects the output of kustomize build . to the kubectl apply command.

kubectl apply command is used to apply or update Kubernetes resources defined in a manifest file. The -f flag specifies that the resources to be applied are in the following file. The - (dash) represents the standard input or output. By using - after the -f flag, it tells kubectl apply to read the resource definition from the standard input.

So, when running this command, the output generated by kustomize build . is piped as input to kubectl apply -f -, which then applies the generated Kubernetes resources to the cluster.