Networking

Why Add a Custom DNS Zone? Adding a custom DNS zone in CoreDNS can be useful for: Internal testing (e.g., *.local or *.internal) Service discovery for non-Kubernetes services Custom mappings and overrides Step-by-Step Guide 1. Edit the CoreDNS ConfigMap kubectl -n kube-system edit configmap coredns Add a new zone block like this: apiVersion: v1 kind: ConfigMap metadata: name: coredns namespace: kube-system data: Corefile: | .:53 { errors health kubernetes cluster.local in-addr.arpa ip6.arpa { pods insecure fallthrough in-addr.arpa ip6.arpa } forward . /etc/resolv.conf cache 30 loop reload loadbalance } internal.test:53 { hosts { 10.10.10.10 service1.internal.test 10.10.10.11 service2.internal.test fallthrough } } 2. Restart CoreDNS kubectl -n kube-system rollout restart deployment coredns 3. Test the Zone From any pod: ...

Why Use Custom DNS Zones in NodeLocal DNSCache? NodeLocal DNSCache speeds up DNS resolution in Kubernetes by running a local CoreDNS instance on each node. Adding custom zones allows: Fast resolution of static or internal domains DNS overrides without relying on upstream resolvers Separation of internal and external DNS logic Step-by-Step Guide 1. Get the NodeLocal DNS ConfigMap kubectl -n kube-system get configmap node-local-dns -o yaml > node-local-dns.yaml 2. Add Custom Zones Inside the Corefile section, add your custom zone using the hosts plugin: ...

Introduction How does Kubernetes know where to send traffic for your services? That’s the job of kube-proxy. Whether you’re accessing a ClusterIP, NodePort, or LoadBalancer — kube-proxy is working behind the scenes to route traffic correctly. Let’s unpack how it works in a way that’s easy to understand. What is kube-proxy? kube-proxy is a network component that runs on every node in your Kubernetes cluster. It’s responsible for: Handling traffic for Kubernetes Services Managing IP rules and routing Forwarding requests to the right Pods kube-proxy acts like a traffic router inside your Kubernetes cluster. ...

Introduction to HTTP HTTP (HyperText Transfer Protocol) is the foundation of data communication on the web. It’s a client-server protocol used for fetching resources such as HTML documents, images, and APIs. HTTP Versions Overview HTTP/1.1 Released in 1997 Supports persistent connections (keep-alive) Still widely used Limitation: Head-of-line blocking HTTP/2 Binary protocol introduced in 2015 Multiplexing: Multiple streams over a single TCP connection Header compression (HPACK) Server push (optional) Faster than HTTP/1.1 HTTP/3 Uses QUIC instead of TCP Built-in encryption (TLS 1.3 only) Better performance on lossy networks Fully multiplexed, no head-of-line blocking WebSockets WebSockets provide a full-duplex communication channel over a single TCP connection. ...