introduction to kubernetes slide deck by Roach
- 1. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public Why use an orchestrator
- 2. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public Application Anatomy Application Server Database Web Server Login Service Photo Upload Like Service Comment Service Profile Service Logging Service Photo Processing Friend Requests
- 3. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public Redesign Image Sharing App Microservice 1 Microservice 2 Microservice n Team 1 Team 2 Team n … DB1 … DB2 DBn Web front End iOS App Android App API Service
- 4. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public • Autonomous • Microservice can be upgraded independent of other systems • Microservice can iterate as quickly as it needs • Polyglot application stacks (Technology Heterogenity) • Other microservices are black boxes to other services • Service can be used by other projects in the organization Advantages of Microservices
- 5. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public Using docker CLI is all well and good as a developer.. But you’re probably not going to manage production like this… Host / VM 2 Linux Kernel Docker Engine Container $ssh host1 host1# docker run container $ssh host2 host2# docker run container $ssh host3 host3# docker run container Host / VM 3 Linux Kernel Docker Engine Container Host / VM 1 Linux Kernel Docker Engine Container
- 6. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public Container Container Container Kubernetes Load Balancing Health Checks Log Aggregation / Access Developer API Container orchestration is a must. $kubectl scale deployment <name> --replicas=3 Once you’ve built your containers and pushed them. Container Orchestrators manage running containers across a pool of resources for you
- 7. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public • Docker Swarm / EE • Apache Marathon • Rancher (seem to be moving towards k8s) What are other orchestrators?
- 8. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public What is kubernetes?
- 9. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public • Container Orchestration • Keeping your containers up, scaling them, routing traffic to them • Kubernetes != Docker though K8S uses Docker (or CoreOS rkt) What is Kubernetes?
- 10. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public • MiniKube (local workstation) • Installers (on-prem, hybrid, custom) • Kops (part of core kubernetes.io github) • Kubespray (Ansible + Terraform) • Etc, etc… • Cloud • Google Container Engine (GKE J) • Azure Container Service • Amazon EKS • Etc… Installation options
- 11. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public • Step-by-step tutorial of how to assemble a kubernetes cluster • https://github.com/kelseyhightower/kubernetes-the-hard-way Sidebar: K8S the hard way
- 13. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public Kubernetes Components
- 14. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public Kubernetes main Features Pods Deployments Services Ingress
- 15. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public • Group of one or more containers, shared storage, and options for how to run the containers • Share IP address and port space • Atomic unit of management Pods Source: http://kubernetes.io/docs/user-guide/pods/
- 16. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public • Rolling upgrades • Declare intent: How many replicas should be running of a given pod? • Namespace • Labels • Ports that should be exposed Deployments
- 17. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public • Abstraction for the mortality of Pods • Provide single stable name and address for a set of pods inside the cluster (aka service discovery). Services Source: http://kubernetes.io/docs/user-guide/services/
- 18. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public • Abstraction for services • An Ingress is a set of rules for directing inbound traffic to a service. • An Ingress Controller is a service that listens for the creation of new services and does reverse proxy (nginx, traefik, f5 loadbalancer) Ingress See: http://kubernetes.io/docs/user-guide/ingress/
- 19. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public K8S templates: deployment # k8s/dev/api-deployment.yaml apiVersion: extensions/v1beta1 kind: Deployment metadata: name: rest-api-swagger spec: replicas: 2 template: metadata: labels: app: rest-api-swagger spec: containers: - name: rest-api-swagger image: ciscodevnet/rest-api-swagger:latest ports: - containerPort: 10010
- 20. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public K8S templates: service # k8s/services/api-service-lb.yaml kind: Service apiVersion: v1 metadata: name: rest-api-swagger spec: type: LoadBalancer # or NodePort, etc. ports: - name: http port: 8080 targetPort: 10010 protocol: TCP selector: app: rest-api-swagger
- 21. © 2018 Cisco and/or its affiliates. All rights reserved. Cisco Public Manual kubectl deployment $ kubectl apply -f k8s/dev/api-deployment.yaml $ kubectl apply -f k8s/services/api-service-lb.yaml $ kubectl describe deployment $ kubectl describe service rest-api-swagger $ kubectl delete -f k8s/dev/api-deployment.yaml $ kubectl delete -f k8s/services/api-service-lb.yaml