Allow connection outside kubernetes cluster
To summarize our discussion on comments:
The solution was to change headless service to Nodeport Service.
The problem was that edit of a service resulted in error because some service's fields are immutable (error: Invalid value: "": field is immutable). Service had to be recreated.
The solution was to use --force flag with helm.
> helm upgrade --help | grep force--force force resource updates through a replacement strategy