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Containerization & Orchestration/Kubernetes/workloads/09-Services.md

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+# 🔗 Services in Kubernetes (SVC)
+
+A **Service** in Kubernetes provides a stable networking interface to access a set of pods. It allows for decoupling between client applications and the underlying pods by using DNS names and selectors.
+
+---
+
+## 🌐 Service Basics
+
+### 📌 Service Flow
+```
+
+Service ➡️ Endpoint ➡️ Pods
+
+````
+
+- Services abstract access to a group of pods.
+- Services automatically get a DNS name in the cluster.
+- They use selectors to route traffic to matching pods.
+
+---
+
+## 🧭 Service Types
+
+1. **ClusterIP** (default)  
+   - Accessible only within the cluster.
+
+2. **NodePort**  
+   - Exposes the service on a static port on each node.
+
+3. **LoadBalancer**  
+   - Provisions an external IP via a cloud provider to expose the service.
+
+---
+
+## 🧪 Useful Commands
+
+### 🔍 Get Endpoints
+```bash
+kubectl get ep -n <namespace>
+````
+
+### 📄 Get Services
+
+```bash
+kubectl get svc -n <namespace>
+```
+
+---
+
+## 🧾 Example Service Manifest
+
+```yaml
+apiVersion: v1
+kind: Service
+metadata:
+  name: nginx
+  namespace: ns
+  labels:
+    app: web-server
+spec:
+  type: ClusterIP  # Options: ClusterIP, NodePort, LoadBalancer
+  selector:
+    app: nginx
+  ports:
+    - name: http  # Port name is optional but useful
+      port: 80  # Service port
+      targetPort: 8080  # Container port
+```
+
+> 🔍 **Note:** The `selector` must match pod labels for the service to route traffic correctly.
+> 🧠 **Tip:** Use `kubectl describe svc <svc-name>` to troubleshoot or verify service-to-pod connectivity.
+> 🌐 Services are resolved by DNS using the format: `<service-name>.<namespace>.svc.cluster.local`.
+