Adds docs.

docs/guides/troubleshoot-service-connectivity.md

@@ -0,0 +1,18 @@
+# Troubleshoot Service Connectivity
+
+If services can't communicate:
+
+1. Check network policies:
+   ```bash
+   kubectl get networkpolicies -A
+   ```
+
+2. Verify service endpoints:
+   ```bash
+   kubectl get endpoints -n <namespace>
+   ```
+
+3. Test connectivity from within the cluster:
+   ```bash
+   kubectl run -i --tty --rm debug --image=busybox --restart=Never -- wget -O- <service-name>.<namespace>
+   ```