Cloud-Native Networking
Ingress, Mesh, and the Death of the Static IP
1. North-South: The Ingress Controller
North-South traffic refers to communication between the outside world (the internet) and your services inside the cloud.
- Ingress: Acts as the entry point. It handles SSL termination, URL routing (e.g., `pingdo.net/api` vs `pingdo.net/app`), and load balancing.
- Gateway API: The modern replacement for Ingress, providing more granular control for multi-cloud deployments.
2. East-West: The Service Mesh
East-West traffic refers to microservices talking to each other inside the cluster. As applications grow to hundreds of services, managing cross-service communication becomes a nightmare.
A Service Mesh (like Istio or Linkerd) solves this by injecting a tiny proxy (Sidecar) next to every application.
Service Mesh & Sidecar Lab
L7 Traffic Policies & Identity-Based Security
Insecure Channel Warning
Traffic is traversing the network in cleartext. Anyone with access to the cluster networking can sniff headers.
The Envoy proxy is "injected" into the pod. The application thinks it's talking to a database, but it's actually talking to the sidecar, which then negotiates the secure connection.
Implementing TLS in code is hard. Implementing it at the mesh level is zero-code. The mesh handles certificate rotation and encryption automatically.
Every time a packet moves through a proxy, it adds a tiny fraction of a millisecond. In high-frequency trading, this matters. In standard web apps, the security gains far outweigh the 0.5ms delay.
Benefits of a Service Mesh
- mTLS (Mutual TLS): Automatically encrypts every service-to-service connection without changing any code.
- Observability: Provides a real-time "map" of which services are talking and where the latency is occurring.
- Traffic Splitting (Canary): Allows you to send 1% of traffic to a new version of a service to test it before a full roll-out.
Conclusion
Ingress manages the entrance; Service Mesh manages the interior. Together, they create a "Zero Trust" network where every packet is authenticated and every connection is monitored, allowing developers to focus on features instead of connectivity.