KubeCon Talk 2016- Basics of Kubernetes Service Discovery

Demo uses https://coreos.com/kubernetes/docs/latest/network-troubleshooting.html

Transcript

1. Brandon Philips @brandonphilips | brandon@coreos.com | coreos.com Kubernetes Service Discovery Fundamentals and Extensions
2. 90+ Projects on GitHub, 1,000+ Contributors OPEN SOURCE Secure solutions, support plans, training + more ENTERPRISE CoreOS is Running the World’s Containers Linux
3. Examples minikube
4. - Use the quickstart tutorial - Or try out rkt quickstart - Ensure you get kubectl work: kubectl get nodes NAME STATUS AGE minikube Ready 6m minikube
5. Overview Label Service Discovery
6. Fundamental API Server - API Server is bedrock of discovery - Available at well-known URL - Protected by TLS and accounts
7. Fundamental Labels
8. Fundamental Labels
9. kubectl run nginx --image=nginx -l app=nginx kubectl get replicaset -l app=nginx kubectl get pods -l app=nginx -w Fundamental Labels
10. Fundamental Labels
11. kubectl expose deployment nginx --port 80 --type=NodePort minikube service nginx Fundamental Labels
12. Overview Above the API
13. - Configured statically in kubelet (--cluster-dns) - Injected into /etc/resolv.conf of containers - Meta alert: DNS Service IP backed by Kubernetes - kubectl describe service -n kube-system kube-dns DNS Add-on
14. Name: kube-dns Namespace: kube-system Labels: k8s-app=kube-dns Selector: k8s-app=kube-dns Type: ClusterIP IP: 10.0.0.10 Port: dns 53/UDP Endpoints: 10.1.0.3:53 kube-dns the service
15. DNS Add-on Basics API Server kube-dns Service 10.0.0.10 dig +vc -p @10.0.0.10 kube-dns.kube-system.svc.cluster.local ;; QUESTION SECTION: ;kube-dns.kube-system.svc.cluster.local. IN A ;; ANSWER SECTION: kube-dns.kube-system.svc.cluster.local. 30 IN A 10.0.0.10
16. Copy/paste one-liner to forward DNS to localhost $ dig +vc -p 5300 @127.0.0.1 cluster.local kube-dns proxy to localhost
17. $ dig A etcd-0000.default.cluster.local etcde-0001.default.svc.cluster.local. 30 IN A 10.0.0.40 $ dig SRV _client._tcp.etcd-0000.default.cluster.local IN SRV 10 100 2379 etcde-0001.default.svc.cluster.local. DNS Add-on - Records
18. $ dig A etcd-0000 IN A 10.0.0.40 $ dig A etcd-0000.default IN A 10.0.0.40 DNS Add-on - Search
19. Full docs are comprehensive I helped write them :) http://kubernetes.io/docs/admin/dns/ kube-dns full docs
20. tectonic.com/summit - @TectonicSummit December 12 & 13 2016 - New York City
21. Thank you! Brandon Philips @brandonphilips | brandon@coreos.com | tectonic.com We’re hiring in all departments! Email: careers@coreos.com Positions: coreos.com/ careers