Spring Boot, Microservices, Containers and Kubernetes - How To

@saturnism @bretmcg @kubernetesio @googlecloud #s2gx

Java MicroservicesWith Kubernetes - How To


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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

Redis

session replication

greeting

MySQL

GuestbookService

CRUD


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

libs

app

app app

No isolation

No namespacing

Common libs

Highly coupled apps and OS

app


Old Java Way: Shared App Server

App Server

libs

app

app app

No isolation

No namespacing

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

app


Old Way: Virtual machines

Some isolation

Expensive and inefficient

Still highly coupled to the guest OS

Hard to manageapp

libs

kernel

libs

app app

kernel

app

libs

libs

kernel

kernel


New Way: Containers

libs

app

kernel

libs

app

libs

app

libs

app


Containerize Option #1

Dockerfile



spotify/docker-maven-plugin

mvn docker:build

https://github.com/spotify/docker-maven-plugin

https://github.com/spotify/docker-maven-plugin



Docker Hub / GitHub

saturnism/spring-boot

https://registry.hub.docker.com/u/saturnism/spring-boot/

https://registry.hub.docker.com/u/saturnism/spring-boot/


Let’s run the container!

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


MySQL

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


Redis

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


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

}

10000

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!

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!

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!

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

Redis

session replication

greeting

MySQL

GuestbookService

CRUD


Version 1.0

Hosted on GitHub

450+ contributors

15,900+ commits

9,600+ GitHub stars

CoreOS

HP

IBM

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

diff

act


Replication Controllers

Node1

Pod

ContainerContainerContainerContainer

Node2

Pod


Pod


Node4

Pod


Pod


Node3

Pod


Replication Controller- Desired = 6- Current = 6

Kubelet Proxy Kubelet Proxy

Kubelet ProxyKubelet Proxy



Node1

Pod


Node2

Pod


Pod


Node4

Pod


Pod


Node3

Pod




Kubelet ProxyKubelet Proxy



Node1

Pod


Node4

Pod


Pod


Node3

Pod




Kubelet Proxy



Node1

Kubelet Proxy

Pod


Node3

Kubelet Proxy

Pod



Pod


Pod


Node4

Kubelet Proxy

Pod


Pod




Node1

Kubelet Proxy

Pod


Node3

Kubelet Proxy

Pod



Pod


Pod


Node4

Kubelet Proxy

Pod


Node2

Pod


Pod


Pod


Kubelet Proxy



Node1

Kubelet Proxy

Pod


Node3

Kubelet Proxy

Pod



Pod


Pod


Node4

Kubelet Proxy

Pod


Pod


Node2

Kubelet Proxy

Pod


Pod




Node1

Kubelet Proxy

Node3

Kubelet Proxy

Pod



Pod


Pod


Node4

Kubelet Proxy

Pod


Pod


Node2

Kubelet Proxy

Pod



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


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

Pod

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

Pod

frontend

Pod

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

or…

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

Redis

session replication

greeting

MySQL

GuestbookService

CRUD


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/

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

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


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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Transcript of Spring Boot, Microservices, Containers and Kubernetes - How To