Apache OpenWhisk + Kubernetes- A Perfect Match

1 .Apache OpenWhisk + Kubernetes: A Perfect Match for Your Serverless Platform Ying Chun Guo Zhou Xing guoyingc@cn.ibm.com xingzhou@qiyi.com 

2 .Agenda •  What is serverless? •  Kubernetes + Apache OpenWhisk •  Technical details •  Demo 

3 .What is serverless ? 

4 .What is serverless ? Functions as a Service Serverless＝ Backend as a Service Benefits •  Zero server ops –  No provisioning, updating, and managing server infrastructure. –  Flexible Scalability •  No compute cost when idle 

5 .Serverless landscape defined in CNCF 

6 .Kubernetes + Apache OpenWhisk 

7 . Kubernetes Introduction §  K8s is a production- grade container orchestration platform §  Declarative management of objects using configuration files. §  More introductions, go to •  K8s official document http://kubernetes.io •  Open Tech Mini Academy @ IBM http://ibm.biz/opentech-ma 

8 .Kubernetes Resource Model A common resource model can satisfy any deployment requirements §  Config Maps §  K8s通过这些资源模型构建应用程序 §  Daemon Sets §  Deployments §  每一种资源都可以被用户所创建并存储在K8s数 §  Events 据库中 §  Endpoints §  Ingress §  用户通过这些创建这些资源“描绘”应用程序在 K8s平台上部署后的样子，K8s会根据这些资源 §  Jobs 的描述尽可能完成对应用程序和服务的部署 §  Nodes §  Namespaces §  这其中，Pod包含了一组共享Linux Namespace §  Pods 的容器，是K8s平台所能调度的最小单元。其他 §  Persistent Volumes 多种资源，例如Deployment，Job等，都是构建 §  Replica Sets 在Pod的基础概念之上的。 §  Secrets §  Services §  用户可以通过kubectl配合描述资源的yaml文件 §  Stateful Sets… 创建这些资源 

9 .Helm •  The package manager for Kubernetes •  Easy to create, version, share, and publish — so start using Helm and stop the copy- and-paste madness. •  Help you define, install, and upgrade even the most complex Kubernetes application. •  Official community： https://helm.sh/ 

10 .Core concepts in Helm Helm installs charts into Kubernetes, creating a new release for each installation. And to find new charts, you can search Helm chart repositories. 

11 .Apache OpenWhisk A serverless, open source cloud platform that executes functions in response to events at any scale. Apache OpenWhisk offers: •  Apache Software Foundation (ASF) •  True, community-driven open source (Apache 2 License) •  Proven on IBM Cloud •  Exact, same code in open source Source event Result Trigger Action Rule 

12 .Architecture of Apache OpenWhisk 

13 .Deploy Apache OpenWhisk on Kubernetes •  The architecture diagram of OpenWhisk components on Kubernetes, e.g. •  https://github.com/apache/incubator-openwhisk-deploy-kube 

14 .Technical details 

15 . Deployment •  A Deployment controller provides declarative updates for Pods and ReplicaSets. •  Stands for a long running task, can be exposed as K8s services •  In OpenWhisk, usually, we deploy those core components’ dependencies lib or tools as Deployment: –  CouchDB –  Redis –  Zookeeper –  Nginx 

16 . StatefulSet/DaemonSet •  StatefulSet is the workload API object used to manage stateful applications. Manages the deployment and scaling of a set of pods, and provides guarantees about the ordering and uniqueness of these Pods •  A DaemonSet ensures that all (or some) Nodes run a copy of a Pod •  In OpenWhisk, we deploy strictly mangaged objects as StatefulSet or DaemonSet: –  Controller –  Invoker –  Kafka 

17 .Jobs •  A job creates one or more pods and ensures that a specified number of them successfully terminate. •  Job stands for a short running task •  In OpenWhisk, we used to deploy package installation and tasks like catalog installation as Job: –  Package installation –  Catalog installation 

18 .Service •  A Kuberentes Servcie is an abstraction which defines a logical set of Pods and a policy by which to access them. •  Service provides a way for applications to communicate with each other on K8s platform •  In OpenWhisk, we deploy all the dependencies as service, usually, they are deployed as ClusterIP service: –  Controller –  Invoker –  Nginx –  Kafka –  Zookeeper –  Redis 

19 .Other objects used in OW charts •  ConfigMap: like nginx deployment configuration •  Secrets: like DB access credentials •  Ingress 

20 .Component Launch Sequence •  In Kubernetes, we can use the following mechanisms to handle the component launch sequence: –  Init Container: a pre-handling container to process staff which need to be done before the major costainer starts –  Probe: readiness probe and liveness probe 

21 .Component Deployment Topology •  Use affinity to make deployment topology policies for different component. E.g. controller node and DB node may not be assigned to the same K8s node •  Affinity type –  Node Affinity –  Pod Affinity 

22 .Demo 

23 .Steps 1.  Create a namespace 2.  Label worker nodes to execute user actions 3.  Create a mycluster.yaml file to customize the deployment 4.  Deploy with Helm 5.  Wait…and done 

24 .