I've implemented the shell of a microservices-based REST API application. I have simply followed the guides on Pivotal Springs' own documentation using Eureka and Ribbon for load balancing. Everything works. I have a discovery server with a handful of independent services which can register with the discovery server.
Now, my problem is that I might prefer not to write my client-side app in Java - maybe Angular or node.js, etc. However, the load balancing and connecting to the discovery server is all done in Java in the examples I've followed.
Is it possible to use JavaScript to do the same things that the Eureka client does with the Spring Boot microservices so that I don't need to be constrained in my choices of browser client technology? Does anybody have any advice for how this should be approached? I had difficulty finding any articles that cover this, to be honest.
Actually you should not be doing load balancing/service discover etc. in the front-end. So the question about whether it is possible in JavaScript or with which libraries is irrelevant.
Typically you'll have an API gateway or a (load balancing) proxy which works with your service registry and routes requests accordingly. In the current project we use Consul for service registry and Nginx + consul-template as proxy. We plan to migrate to some API gateway.
With this setup your front-end will connect to just one central endpoint which would do load balancing/routing to individual service instances behind the scenes. Thus your front-end will not need to implement anything like Eureka/Ribbon etc.