spring boot, microservices, containers and kubernetes - how to

@saturnism @bretmcg @kubernetesio @googlecloud #s2gx

Java MicroservicesWith Kubernetes - How To

SPRINGONE2GXWASHINGTON, DC

Microservices, Containers, Kubernetes - How To

Ray Tsang / Bret McGowen@saturnism / @bretmcg

Bret McGowenDeveloper AdvocateGoogle Cloud PlatformNew York, NY

@bretmcg

About Bret

Ray TsangDeveloper Advocate

@saturnism | +RayTsang

Ray TsangDeveloperArchitectTravelerPhotographer

flickr.com/saturnism

Microservices?

You probably heard a lot already!

No theories here - just a how to

Hello World Service - Greet

Guestbook Service - Create

Guestbook Service - Retrieve

GuestbookUI

Hello World Service

session replication

greeting

GuestbookService

Package & Deploymentapplication.ear

app.war

helloworld-service.jar

guestbook-service.jar

apache-xyz.jar

application.war

apache-xyz.jar

Machine

app.war / app.ear

Application Server

Kernel

Shell / CLI / Tools

Machine

app.war / app.ear

Application Server

Kernel

Shell / CLI / Tools

Machine

app.war / app.ear

Application Server

Kernel

Shell / CLI / Tools

Machine

app.war / app.ear

Application Server

Kernel

Shell / CLI / Tools

Microservices Way?

Package & Deployment

app.jar

Deployment? Just run it!

java -jar helloworld-service.jar

java -jar guestbook-service.jar

java -jar app.jar

Characteristics

Easy to deploy

Fast startup time

Self-contained Jar

Embedded Java ServersSpring Boot, JBoss Wildfly Swarm, Fluent-HTTP, Vert.x, Ninja,

Spark, Jodd, ...

Let’s see some code

So many servicesDeploy, Manage, Ports, Discovery, Isolation… How?

Containers

Old Way: Shared machines

kernel

app app

No isolation

No namespacing

Common libs

Highly coupled apps and OS

Old Java Way: Shared App Server

App Server

app app

No isolation

No namespacing

Common libs - shouldn’t really happen in Java apps...

Old Way: Virtual machines

Some isolation

Expensive and inefficient

Still highly coupled to the guest OS

Hard to manageapp

kernel

app app

kernel

New Way: Containers

kernel

Containerize Option #1

Dockerfile

spotify/docker-maven-plugin

mvn docker:build

Docker Hub / GitHub

saturnism/spring-boot

Let’s run the container!

docker run -ti -p 8080:8080 helloworld-service

docker run -d --name mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=yourpassword -e MYSQL_DATABASE=app mysql

docker run -d --name redis redis

Guestbook Service

docker run -ti --name guestbookservice --link mysql:mysql saturnism/guestbook-service

Hello World Service

docker run -ti --name helloworldservice \saturnism/spring-boot-helloworld-service:1.0

Guestbook UI

docker run -ti --rm --link redis:redis \--link helloworldservice:helloworldservice \--link guestbookservice:guestbookservice \

-p 8080:8080 saturnism/spring-boot-helloworld-ui

Docker Compose

docker-compose up

Containers & Orchestration To the Rescue!

Everything at Google runs in containers

Launch over 2 billion containers per week.

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 = 5 // Number of tasks

Developer View

web browsers

BorgMaster

link shard

UI shardBorgMaster

link shard

UI shardBorgMaster

link shard

UI shardBorgMaster

link shard

UI shard

Scheduler

borgcfg web browsers

scheduler

Borglet Borglet Borglet Borglet

Config file

BorgMaster

link shard

UI shard

persistent store (Paxos)

Binary

Developer View

What justhappened?

Hello world!

Hello world!Hello

world! Hello world! Hello

world!

Hello world!

Hello world!Hello world!

Hello world!

Hello world! Hello

world!

Hello world!

Image by Connie Zhou

Hello world!

Hello world! Hello

world!

Hello world! Hello

world!

Hello world!

Hello world! Hello

world!

Hello world! Hello

world!

Hello world!

Hello world! Hello

world!

Hello world! Hello

world!

Hello world!

Developer View

Data Center as One Machine

Open Source To the Rescue!

Enter Kubernetes

Greek for “Helmsman”; also the root of the word “Governor”

• Container orchestrator

• Runs containers

• Supports multiple cloud and bare-metal environments

• Inspired and informed by Google’s experiences and internal systems

• Open source, written in Go

Manage applications, not machines

GuestbookUI

Hello World Service

session replication

greeting

GuestbookService

Version 1.0

Hosted on GitHub

450+ contributors

15,900+ commits

9,600+ GitHub stars

CoreOS

Mesosphere

Microsoft

Project Partners

Open Source Community

Pivotal

Red Hat

SaltStack

VMWare

https://github.com/GoogleCloudPlatform/kubernetes

Challenges

Which host machine(s) should each process run on?

How does the application code 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?

web browsers

Scheduler

kubectl web browsers

scheduler

Kubelet Kubelet Kubelet Kubelet

Config file

Kubernetes Master

Container Image

Developer View

What justhappened?

Developer View

spec: containers: - name: mysql image: mysql resources: limits: memory: "128Mi" cpu: "0.1" ports: - containerPort: 3306 protocol: TCP replicas: 110000

Cluster of Machines as One

PodsThe atom of cluster scheduling & placement

Ephemeral

● can die and be replaced

Small group of containers & volumes

Tightly coupled

Shared namespace

● share IP address & localhostPod

Log Collector Web Server

Volume

Consumers

Pod Networking

10.1.1.0/24

10.1.1.93

10.1.1.113

10.1.2.0/24

10.1.2.118

10.1.3.0/24

10.1.3.129

Responsible for maintaining the desired state

Monitor the current state

Similar to a process supervisor

Replication Controller

observe

Replication Controllers

ContainerContainerContainerContainer

Replication Controller- Desired = 6- Current = 6

Kubelet Proxy Kubelet Proxy

Kubelet ProxyKubelet Proxy

Kubelet Proxy

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

Hide complexity• ideal for non-native apps

Servicesstable IP / port

Labels

App == Guestbook

App: GuestbookPhase: Test

Role: Frontend

Role: Backend

App: GuestbookPhase: Dev

Role: Frontend

Role: Backend

App: EncodingPhase: Prod

Role: Backend

Labels

Role == Frontend

Role: Frontend

Role: Backend

Role: Frontend

Role: Backend

Labels

Role: Frontend

Role: Backend

Role: Frontend

Role: Backend

App == GuestbookRole == Backend

Role: Backend

Putting it all together

Service

Label selectors: version = 1.0 type = Frontend

Service

Label selector:Role: FE

Pod Pod

frontend

Version: v1 Version: v1

Role: FEVersion: v1#pods = 2

show: version = v2

Role: FE Role: FE

Replication ControllerPod

frontend

Canary

Service

Label selectors: version = 1.0 type = Frontend

Pod Pod

frontend

PodReplication ControllerReplication Controller

show: version = v2

frontend

Version: v2Role: FE

Service

Label selector:Role: FE

Version: v1 Version: v1

show: version = v2

Role: FE Role: FE

Service discovery

Read service IP addresses via environmental variables

Service discovery

Kubernetes API

DNS Lookups!

ping redis

A small group of tightly coupled

containers

Example: application & log collector

A loop that drives current state towards

desired state

Example: replication controller

A set of running pods that work together

Example: load-balanced backends

Arbitrary metadata to organize components

Example: phase=productionrole=frontend

Replication Controller Service LabelsPod

Live Demo

Hello World Service - Greet

Guestbook Service - Create

Guestbook Service - Retrieve

GuestbookUI

Hello World Service

session replication

greeting

GuestbookService

Versioning container image

docker tag spring-boot-demo spring-boot-demo:1.0

Staging vs. production

Use labels - deploy in the same infrastructure

Canary

Use service, and replication controllers to canary new versions

Rollback

Super simple with versioned containers

Rolling upgrade

Similar to canary, but slowly let the new version take over

Vagrantexport KUBERNETES_PROVIDER=vagrant

curl -sS https://get.k8s.io | bash

Google Container Engine - Betahttp://cloud.google.com/container-engine

http://kubernetes.io/gettingstarted/

Try out Google Container Engine

https://cloud.google.com/container-engine/

Try Kubernetes Today!

Thanks!

Images by Connie Zhou

http://kubernetes.io http://bit.ly/1QLg5E1

spring boot, microservices, containers and kubernetes - how to

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