Microservices. Chaos Kontrolle mit Kubernetes. Robert Kubis - Developer Advocate,

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1 Microservices Chaos Kontrolle mit Kubernetes Robert Kubis - Developer Advocate,

2 About me Robert Kubis Developer Advocate Google Cloud Platform London, UK hostirosti github.com/hostirosti 2

3 Agenda 1 Motivation (Microservices) 2 Container Overview 3 Cluster Management & Kubernetes 4 Demo

4 Microservices Google Cloud Platform 4

5 Decomposing Monolithic apps A B C D 5

6 Decomposing Monolithic apps A C B D 6

7 Decomposing Monolithic apps A C B D 7

8 Where should I run my microservices? build and deploy vm images build and deploy apps VM Platform Basic atom Run anything Self-managed Curated runtimes Rich services Auto-everything just add code More agility More Flexibility 8

9 Where should I run my microservices? build and deploy vm images build and deploy containers build and deploy apps VM Cluster Platform Basic atom Run anything Self managed Managed collections Declarative + Dynamic Curated runtimes Rich services Auto-everything just add code More agility More Flexibility 9

10 Containers Overview What is a container? Google Cloud Platform 10

11 Old Way: Shared Machines No isolation No namespacing app app app app Common libs Highly coupled apps and OS libs kernel 11

12 Old Way: Virtual Machines Some isolation Inefficient Still highly coupled to the guest OS app app libs libs kernel kernel app app libs libs kernel kernel Hard to manage 12

13 New Way: Containers app app libs libs app app libs libs kernel 13

14 Concrete Docker Example - Images An image is a stack of Read-Only file system layers. Usual process: build push to repository pull to execution host start container from image App JRE Libs Debian 14

15 Concrete Docker Example - Images Read / Write A container is a process started with kernel restrictions a stack of shared Read-Only file system layers plus a process specific ReadWrite layer Every new container gets a new Read-Write later. All containers from the same image start from exactly the same state! Read / Write Read / Write App JRE Libs Debian 15

16 Mounting Host Directories It's possible to mount host directories into a container's filesystem. These are mutable and do outlive the container. They're only available on that host. Read / Write host dir App PHP & Apache Libs Debian 16

17 Concrete Docker Example App PHP & Apache Service A libs libs Service B Docker Engine libs libs Debian Server 17

18 Why containers? #kubernetesio #jsd2015 Images by Connie Zhou 19

19 Why containers? Performance #kubernetesio #jsd2015 Images by Connie Zhou 20

20 Why containers? Performance Repeatability Quality of #kubernetesio #jsd2015 Images by Connie Zhou 21

21 Why containers? Performance Repeatability Quality of service #kubernetesio #jsd2015 Images by Connie Zhou 22

22 Why containers? Performance Repeatability Quality of service Accounting #kubernetesio #jsd2015 Images by Connie Zhou 23

23 Why containers? Performance Repeatability Quality of service Accounting Portability A fundamentally different way of managing #kubernetesio #jsd2015 Images by Connie Zhou 24

24 containers are awesome let's use lots of them! 25

25 Cluster Management and Kubernetes Google Cloud Platform 26

26 Everything at Google runs in containers: Gmail, Web Search, Maps,... MapReduce, batch,... GFS, Colossus,... Even Google Compute Engine: VMs in #kubernetesio #jsd

27 Image by Connie Zhou 28

28 Developer View job hello_world = { runtime = { cell = 'ic' } // Cell (cluster) to run in binary = '.../hello_world_webserver' // Program to run args = { port = '%port%' } // Command line parameters requirements = { // Resource requirements ram = 100M disk = 100M cpu = 0.1 } replicas = // Number of tasks } 29

29 Developer View 30

30 Binary Config file webbrowsers browsers web borgcfg What just happened? BorgMaster UIshard shard BorgMaster UI BorgMaster UI shard BorgMaster UIshard shard BorgMaster UI persistent store (Paxos) Scheduler scheduler linkshard shard link link shard link shard link shard Borglet Borglet Borglet Borglet 31

31 (Borg paper) Image by Connie Zhou 32

Enter Kubernetes Greek for Helmsman ; also the root of the word Governor Container orchestrator Runs Docker containers Supports different cloud and

32 Enter Kubernetes Greek for Helmsman ; also the root of the word Governor Container orchestrator Runs Docker containers Supports different cloud and bare-metal environments Inspired and informed by Google s experiences and internal systems Open source, written in Go Manage applications, not machines 33

33 Kubernetes Architecture web webbrowsers browsers Kube-UI Kubernetes Master kubectl Replication Controller Proxy Scheduler API Server <Your App> Kubelet Kubelet y Kubelet Kubelet Container Registry 36

34 Desired State Google Cloud Platform 37

35 Guestbook App Mongo php php php Nginx php Spring Java Redis 38

36 Challenges Which host machine(s) should each process run on? How does the Java microservice find the cache process? How do we keep all of these processes running? What happens if a host machine has trouble? Are the processes healthy? How do we scale when load changes? Run this in another environment? QA, dev, another cloud, your servers? 39

Kubernetes Concepts Pod A small group of tightly

& web server Replication Controller Service

desired state A set of running pods that work

components Example: replication controller

37 Kubernetes Concepts Pod A small group of tightly coupled containers Example: static site generator & web server Replication Controller Service Labels A loop that drives current state towards desired state A set of running pods that work together Arbitrary metadata to organize components Example: replication controller Example: loadbalanced backends Example: phase=production role=frontend 40

38 Pods Consumers The atom of cluster scheduling & placement Ephemeral can die and be replaced Application specific logical host Web Server Single container pods can be created directly from a container image Pod Volume 41

39 Pods The atom of cluster scheduling & placement Content Manager Consumers Ephemeral can die and be replaced Small group of containers & volumes Site generator Web Server Tightly coupled Shared namespace share IP address & localhost Pod Volume 42

40 Replication Controller Responsible for maintaining the desired state observe Monitor the current state Similar to a process supervisor act diff 43

41 Services A group of pods that act as one == Service Load balances across healthy pods Gets a stable virtual IP and port also a DNS name stable IP / port Hide complexity ideal for non-native apps 44

42 Labels App: Guestbook Phase: Dev Role: Frontend App: Guestbook Phase: Dev Role: Backend App: Guestbook Phase: Test Role: Frontend App: Guestbook Phase: Test Role: Backend Arbitrary metadata Attached to any API object Generally represent identity Queryable by selectors think SQL select... where... The only grouping mechanism pods under a ReplicationController pods in a Service capabilities of a node (constraints) Example: phase: canary 45

43 Scheduling Predicate based currently Pod Selection Node Capacity (based on requested resource limits) Prioritisation Nodes that match all predicates are ranked Priority for Node whose already-running pods consume the least resources More to come! 46

44 Map to Kubernetes Mongo php php Nginx php Spring Java php Redis 47

45 Google Container Engine Managed Kubernetes (v1) Manages Kubernetes Uptime Manages Updates Logging agents run on cluster instances, recording log entries that can be viewed in Cloud Logging Use Google Cloud VPN to have cluster IPs coexist with your private network IPs 48

46 Demo - Guestbook Google Cloud Platform 49

Frequently Asked Questions Q. How does Kubernetes handle secrets? docs/secrets.md Q. How will Kubernetes scale pods? docs/proposals/autoscaling.

47 Frequently Asked Questions Q. How does Kubernetes handle secrets? docs/secrets.md Q. How will Kubernetes scale pods? docs/proposals/autoscaling.md (Based on Traffic, predictive analysis or arbitrary data) Q. How will Kubernetes scale nodes? (Likely based on Utilization and signals from scheduler) Q. How can we make Kubernetes highly available docs/availability.md 50

Google Container Engine https://cloud.google.

48 Google Container Engine google-containers google group Kubernetes irc.freenode.net Google Cloud Platform 51

Vielen Dank fuer die Aufmerksamkeit! Fragen?

49 Vielen Dank fuer die Aufmerksamkeit! #kubernetesio #googlecloud #jsd2015 Google Cloud Platform 52

So, I have all these containers! Now what?

So, I have all these containers! Now what? Image by Connie Zhou Developer View job hello_world = { runtime = { cell = 'ic' } // Cell (cluster) to run in binary = '.../hello_world_webserver' // Program