Opening Scenario
Your monolith has been split into eight services. In development, everything works — services run locally, you call them by localhost:8080, and requests resolve instantly. You deploy to staging. Now Service A can't find Service B. Service C's calls to Service D time out randomly. A deploy of Service E broke Service F with no code changes to either. Nobody changed the firewall.
The networking that was invisible in your monolith is now explicit, fragile, and yours to manage.
Question Progression
1. How do services find each other?
Question: In a monolith, function A calls function B directly. In a microservices environment, Service A needs to call Service B — but B runs as multiple containers, their IPs change on every restart, and they scale up and down dynamically. How does A know where to send the request?
Reasoning: Static IPs don't work at scale. You can't hardcode…
In the full tutorial
- When to Reach for This