I know that the doc says that there is no UI generated for a microservices app. Firstly, why not? Secondly, how can I work around this?
I'm going to be building an app that has three clearly separated groups of functionality that just screams for microservices. However, a big part of the application that I will be presenting is just basic CRUD over a bunch of the data -- exactly what the generated UI is great for. There's lots more that still needs to be developed that isn't the simple CRUD, but for 18 of the tables (spanning two of the three microservices), that's all I need for data management.
It will be a lot easier for me to remove or hide the UI I don't want than to build it up from scratch for those 18. The generated UI is still useful for development and QA, even though that data will always come from an external source in production. I can easily make those pages admin-access only.
If I were to take the same data model, but then build it as microservices in one case, then start a separate project, change it to monolith, and generate UI only, how far would that be from what I'm looking for? Of course, I want all the API calls to be going through the gateway, so from the perspective of the UI code, it's not really different from if the back end were a monolith.
Am I headed for failure with this approach, or will it mostly work and just need a little tweaking to get the pieces to connect properly?
By default, UIs are generated for microservices, they're just generated as part of the gateway. If you want to have the UI packaged with your microservice, you can use micro frontends. I wrote a tutorial that shows you how to use them with JHipster. See Micro Frontends for Java Microservices.