I have a Spring Boot web application that I'd like to split up into about six separate applications; one would provide the homepage and login at endpoints under "/", and the others would each claim a subdirectory path ("/subsystem1", "/subsystem2", etc...). I have a pretty clear idea how I could use JWT to pass authentication/authorization from the login app to the others.
The main reason for this is so that each subsystem can be modified or updated without shutting down the others. And organizationally, so we don't have to subject the entire app to a QA process when only one subsystem is changed.
Is it possible to set up multiple Spring Boot instances to run on the same server at the same time and the same port, with different paths/directories to their endpoints? How?
I was unable to find any duplicate question, but here are two related questions that may offer clues:
From Is there a standard way to customize the deploy path in Spring Boot? I learned that I can set the application property
server.servlet.context-pathto prefix the whole application with a subdirectory name (e.g. "/subsystem1"). But I still can't run two apps at the same time, even if both claim different subdirectories. Spring Boot reports "Web server failed to start. Port 8080 was already in use."There's Multiple Spring-boot applications running on one Tomcat but I'd prefer to use standalone Spring applications with their embedded Tomcat instances rather than the less-recommended WAR packaging and deployment to an external Tomcat container.
This one looks promising -- Deploying Multiple Spring Boot Web Applications in Single Server -- but the answers focus on whether standalone or Tomcat container deployments are better, and doesn't touch on the "how-to" question.
Acceptable answers:
If, as ekalin suggests, it is impossible to have multiple Spring Boot apps listen to the same port, here are a couple of ideas I have brainstormed (but don't know how to accomplish):
Perhaps the instances could be running on different ports but the main app (the one with the login page) could "forward" or redirect to the other apps in some way that hides their true URLs? E.g. "localhost:8080/subsystem1" would be an alias for "localhost:8081/".
Perhaps the applications could each have their own Docker containers, all running within a shared Docker network, and we use Docker somehow to map each URL path to the right app? Could this be set up with docker-compose?
We set up a proxy server of some kind that remaps URL paths to the separate applications.
