What is DNS-based service discovery, and how does it work in microservices?

DNS-based service discovery uses DNS records to resolve service names into IP

addresses. It simplifies service discovery by relying on existing DNS infrastructure and

ensuring that microservices can dynamically find each other without hardcoding addresses.

How it works:

• Service Registration: Each microservice registers its IP address and port with a

DNS resolver or service registry.

• Service Lookup: When a microservice needs to communicate with another, it

queries the DNS for the service's name (e.g.,

service-name.namespace.svc.cluster.local in Kubernetes), which returns

the corresponding IP address.

• Dynamic Updates: As new service instances are added or removed, DNS entries

are automatically updated.

Example: Kubernetes uses CoreDNS for service discovery, where each microservice gets a

DNS name that resolves to the service's IP.