If you’re an active Istio user, then there’s a good chance that Istio’s configuration reference is bookmarked in your browser, and that you’ve read the pages on VirtualServices, and ServiceEntries over and over, but still have to struggle to set up even simple configurations in your mesh. Istio’s custom resource configuration is very powerful and flexible, but infamous for being overly complex. At its best, its YAML consists of lists of lists, cross-references, conflicting fields, and wildcards.