mytls | Mimic TLS/JA3 fingerprint inside Node with help from Go | TLS library

The configMapRef and secretMapRef for the envFrom and valueFrom functions are only available for environment variables which means they cannot be used in this context. The desired functionality is not available in vanilla Kubernetes as of 1.18.0.

However, it can be done. Helm and Kustomize are probably the two best ways to accomplish this but it could also be done with sed or awk. Helm is a templating engine for Kubernetes manifests. Meaning, you create generic manifests, template out the deltas between your desired manifests with the generic manifests by variables, and then provide a variables file. Then, at runtime, the variables from your variables file are automatically injected into the template for you.

Another way to accomplish this is why Kustomize. Which is what I would personally recommend. Kustomize is like Helm in that it deals with producing customized manifests from generic ones, but it doesn't do so through templating. Kustomize is unique in that it performs merge patches between YAML or JSON files at runtime. These patches are referred to as Overlays so it is often referred to as an overlay engine to differentiate itself from traditional templating engines. Reason being Kustomize can be used with recursive directory trees of bases and overlays. Which makes it much more scalable for environments where dozens, hundreds, or thousands of manifests might need to be generated from boilerplate generic examples.

So how do we do this? Well, with Kustomize you would first define a kustomization.yml file. Within you would define your Resources. In this case, myingress: