What is Consul?

Consul is a tool that helps manage and discover services in a distributed system. It acts as a service registry, storing information about every service running in your environment. This makes it easy for services to find and communicate with each other without hard-coding network locations.

How Consul Works with Spring Cloud

Spring Cloud can connect your applications to Consul, allowing them to automatically register themselves and discover other services. When you use Consul with Spring Cloud:

• Each service registers its name, address, and port with Consul;
• Consul keeps a list of all available services and their locations;
• Your services can ask Consul where to find another service by its name;
• Consul updates the registry if a service goes offline or comes online.

Service Registration and Discovery with Consul

When you start a Spring Boot application that is set up for Consul integration, it will:

• Register itself with Consul by sending its details to the Consul server;
• Periodically send health checks so Consul knows it is still available.

If another service needs to communicate, it can:

• Query Consul for the location of the target service using its name;
• Receive the current address and port of a healthy instance of that service.

This approach means you do not need to manually update addresses when services change. Consul and Spring Cloud handle the details, making your system more flexible and reliable.