Developing Java based microservices ready for the world of containers The so-called experts are saying microservices and containers will change the way we build, maintain, operate, and integrate applications. This talk is intended for Java developers who wants to hear and see how you can develop Java microservices that are ready to run in containers. In this talk we will build a set of Java based Microservices that uses a mix of technologies with: - Spring Boot with Apache Camel - Apache Tomcat with Apache Camel You will see how we can build small discrete microservices with these Java technologies and build and deploy on the Kubernets/OpenShift3 container platform. We will discuss practices how to build distributed and fault tolerant microservices using technologies such as Kubernetes Services, Camel EIPs, Netflixx Hysterix, and Ribbon. We will use Zipkin service tracing across all four Java based microservices to provide a visualization of timings and help highlight latency problems in our mesh of microservices. And the self healing and fault tolerant aspects of the Kubernetes/OpenShift3 platform is also discussed and demoed when we let the chaos monkeys loose killing containers. This talk is a 50/50 mix between slides and demo.

1. Developing
Java based microservices
ready for the world of containers
@davsclaus
davsclaus
davsclaus.com
Claus Ibsen

2. I was here in 2015
.. and talking about Apache Camel

3. Claus Ibsen
• Principal Software Engineer
at Red Hat
• Apache Camel
8 years working with Camel
• Author of
Camel in Action books
@davsclaus
davsclaus
davsclaus.com

7. ?

8. ?

9. OS Level Virtualization
Docker Orchestration
PaaS Platform on top of
Kubernetes
Services and Tools for
Kubernetes and OpenShift

10. Kubernetes

11. Kubernetes
‣ Open Source orchestration platform for Docker
containers
• Rewrite of Google’s internal framework “Borg”
‣ Declarative specification of a desired state
‣ Self-healing
‣ Service discovery
‣ Scheduling across hosts
‣ Replication

12. Architecture

13. Key Concepts
‣Nodes
• Worker machine (physical or VM) running pods
‣Pods
• Collection of one or more Docker containers
‣Replication Controller
• Creates and takes care of Pods
‣Services
• Network Proxy for a collection of Pods
‣Labels
• Grouping and organization of Objects
‣Namespaces
• Virtual clusters backend by same physical cluster

14. What is Kubernetes?
http://blog.kubernetes.io/2016/06/illustrated-childrens-guide-
to-kubernetes.html

16. fabric8
‣ Tools and Services for value add to Kubernetes and
OpenShift
• Management: console, logging, metrics, dashboards, …
• Continuous Delivery Workflow
• iPaaS: Camel route visualization, API registry, Messaging as
a Service, …
• Tools: Kubernetes/OpenShift build integration, Kubernetes
component test support, CDI extensions
• Quickstarts: Ready to use examples, also available as
Maven archetypes

17. Kubernetes
Demo Time

18. Java Developer
?

19. Build a
Camel Demo
Time

20. Hello Service
Hello
Service
Client

21. Hello Service
Hello
Service
name=Claus
Hi $name I am $HOSTNAME
Client

22. Implementation
Client Hello Service
HTTP
Apache
Tomcat
Spring Boot

23. Implementation
Hello
Service
Client Hello Service
HTTP

24. Implementation
Client Hello Service
HTTP
from timer
to http
log
from servlet
transform
helloservice

25. Hello Service

26. Client

27. Ready to run local
Client Hello Service
HTTP 8080
from timer
to netty
log
from servlet
transform
helloservice

28. How to build Docker Image?
Maven Project Docker Image

29. Docker Maven Plugin
Maven Project
Docker Maven
Plugin
Docker Image
build

30. Docker Maven Plugin
in pom.xml

31. Docker Maven Plugin
in pom.xml

32. Build Docker Image
mvn clean install docker:build

33. Local Docker Repository
Hello Service
Client

34. Our Demo
Client Hello Service
HTTP 8080
from timer
to http
log
from servlet
transform
helloservice

35. Static vs Dynamic Platform
Client Hello Service
HTTP 8080
from timer
to http
log
from servlet
transform
helloservice
Hardcoded
hostname and port

36. Dynamic Platform
Hello Service
HTTP 8080
Client
from timer
to http
log
from servlet
transform
helloservice
Kubernetes
Service

37. Kubernetes Service
• Network Connection to one or more Pods
• Unique static IP and port (lifetime of service)

38. Kubernetes
Service
HTTP 8080
from timer
to http
log
from servlet
transform
helloservice
kubeproxy
Kubernetes
Master
enlisted on deployment
changes
pod
node
pod
node

39. Kubernetes Service
from user point of view
service ip:port
from timer
to http
log
from servlet
transform
helloservice
pod pod

40. Service defined
in pom.xml
Hello Service
from servlet
transform
helloservice
Container Port =
Inside
Service Port = Outside

41. Using Kubernetes
Service
Client
from timer
to http
log
We want to use hello service
How do we do that?

42. Using Kubernetes
Service
• Environment Variables
• Hostname
• Port
Client
from timer
to http
log
Service Discovery using DNS is available
in newer versions of Kubernetes.

43. Camel using service
• Use {{service:hello}} Client
from timer
to http
log

44. Ready to run in Kubernetes
Client Hello Service
service:hello
from timer
to netty
log
from servlet
transform
helloservice
kubeproxy

45. How to deploy to
Kubernetes?
Maven Project

46. How to deploy to
Kubernetes?
Maven Project
fabric8 Maven
Plugin
apply

47. Deploy - Hello Service
Hello Service
from servlet
transform
helloservice
• mvn -Pf8-local-deploy

48. Deploy - Client
• mvn -Pf8-local-deploy Client
from timer
to http
log

49. fabric8 Web Console

50. OpenShift CLI
• oc get pods
You can also use CLI from
docker &
kubernetes

51. OpenShift CLI
• oc get services

52. OpenShift CLI
• oc logs -f <pod name>

53. OpenShift CLI
No they are not Camel routes,
but networking routes.
• oc get routes

54. Scaling
• Change replication controller replicas

55. Scaling
• Service load balancing
Load balancing
is random

56. Angry Pods
1st person shooter - Kill your pods

57. Zipkin
Distributed message tracing

58. Zipkin
• camel-zipkin (coming in Camel 2.18)
• https://github.com/apache/camel/tree/master/
examples/camel-example-zipkin
• kubernetes-zipkin
• https://github.com/fabric8io/kubernetes-zipkin
• https://github.com/fabric8io/kubeflix/blob/master/
examples/loanbroker/readme.md

59. Links
• fabric8
• http://fabric8.io
• https://blog.fabric8.io/
• Try kubernetes / fabric8
• http://fabric8.io/guide/getStarted/vagrant.html
@davsclaus
davsclaus
davsclaus.com