Want to learn how to manage and deploy Magnolia in a microservices architecture? Here we will present the main patterns identified in such an architecture and describe how to implement them with Magnolia. We demonstrate an experimental approach based on Docker to create and orchestrate several microservices connected to Magnolia.

1. Using Magnolia in a Microservices Architecture
Presented by Nicolas Barbé
Broadcast on 2015-09-10

2. Nicolas Barbé
Software engineer and
technology enthusiast
working for Magnolia

3. MICROSERVICES
“Loosely coupled
service oriented architecture
with bounded contexts”
Adrian Cockcroft

4. Your organisation can scale
WHY DOES IT MATTER?

5. NOT A FREE LUNCH
Distributed systems are complex
๏ Testability
๏ Eventual consistency
๏ Operational complexity
http://highscalability.com/blog/2014/4/8/microservices-not-a-free-lunch.html

6. COMMON PATTERNS

7. REQUEST - RESPONSE
request
response
BLOCKED
one to one and synchronous
client server
This is a service

8. PUBLISH - SUBSCRIBE
publish
one to many and asynchronous
subscribetopic
producer
consumers

9. FACADE
C
Facade B
A
A facade provides an uniformed API
abstracting several underlying services
Request

10. PROXY
C
proxy B
A
A proxy delegates a request to one of the
underlying services
Request

11. CRUD
Create / Read / Update / Delete
Straightforward mapping to DB operators but
does not perform well with task based UI

12. CQRS
Different models for queries and commands
Commands Queries

13. ROLE OF MAGNOLIA
๏ Editorial Content - Magnolia
๏ Dynamic or User Generated Content
๏ Content & Business Logic - Microservices
๏ Frontend - Magnolia
๏ Backend - Magnolia

14. MAGNOLIA ASK
A proof of concept of a Q&A website like stack-overflow

15. WHICH SERVICES?
References must be checked
- Question / Answer
- Question / User
- Answer / User
- Rating / Answer
- Rating / Question
Users have only one vote
Answers are single threaded
USERS
QUESTIONS ANSWERS
RATINGS

16. ARCHITECTURE
USERS-COMMANDS
users
RATINGS-COMMANDS
ANSWERS-COMMANDS
QUESTIONS-COMMANDS
USERS-QUERIES
votes
questions
answers
QUESTIONS-QUERIES
ANSWERS-QUERIES
pub
pub
pub
pub
sub
sub
sub
sub
sub
sub
sub
sub
sub
req/res
req/res
sub
Magnolia
req/res
req/res
req/res

17. ANATOMY OF A MICROSERVICE
Commands Queries
QUESTIONS
‣ AskQuestion
‣ CloseQuestion
{
title: Eget lacinia odio sem nec
elit?
description: Cum sociis natoque
penatibus et magnis dis
parturient ontes, nascetur
ridiculus mus.
initiator: nbarbe
createdAt: 2015-08-14T14:45:43
closed: false
}
‣ ListQuestions
‣ ShowQuestion
{
title: Eget lacinia odio sem nec
elit?
description: Cum sociis natoque
penatibus et magnis dis
parturient ontes, nascetur
ridiculus mus.
initiator: Nicolas Barbé
createdAt: 2015-08-14T14:45:43
closed: false
votes: 12
answers: 3
answersBucketId: fh34t738
}

18. DEEP DIVE IN THE IMPLEMENTATION

19. CONTAINERS
Additional layer of abstraction and
automation of an OS

20. CONTAINERS OR VM?
Actually both !
Virtual machine for the hosts
Containers for the microservices

21. CONTAINER = MICROSERVICE
๏ Clear Boundaries
๏ Reproducible Builds
๏ Network Plumbing
๏ From Dev to Prod to
Dev
๏ Uniform Operations
- Packaging
- Distribution
- Deployment / Upgrade
- Backup / Restore
- Monitoring
- Logging
- Snaphots

22. DOCKERIZE MAGNOLIA
$ echo
'FROM nicolasbarbe/magnolia-base
MAINTAINER Nicolas Barbé "https://github.com/nicolasbarbe"
RUN wget -nv http://sourceforge.net/projects/magnolia/files/
magnolia/Magnolia%20CE%205.4.2/magnolia-bundled-
webapp-5.4.2.war/download?use_mirror=autoselect -O
$CATALINA_BASE/webapps/ROOT.war' > Dockerfile
$ docker build -t magnolia .
$ docker run -p 3000:8080 magnolia

23. TIPS & TRICKS
๏ Follows the recommendations of
the Filesystem Hierarchy Standard
๏ Configuration through
environment variables
- INSTANCE_TYPE
- DB_TYPE
- DB_SCHEMA
- DB_USERNAME
- DB_PASSWORD
- DEVELOP_MODE
- CLUSTER_ID
๏ Tomcat & JVM settings can be
customised
COPY setenv.sh $CATALINA_BASE/bin/setenv.sh
๏ Map a volume from the host to the
container to persist the JCR
repository
-v /var/lib/magnolia/repositories:/var/lib/
magnolia/repositories
๏ Map a volume from the host to the
container for the resources
-v $MAGNOLIA_WEB_RESOURCES:/var/opt/magnolia

24. MORE INFORMATION
http://nicolasbarbe.com/2015/01/02/a-docker-image-for-magnolia/

25. FROM DEV …
Build a clone of the production environment locally with Docker Compose
db-author:
image: postgres
environment:
- POSTGRES_USER=magnolia
- POSTGRES_PASSWORD=mysecretpassword
author:
image: nicolasbarbe/ms-frontend:1.0-SNAPSHOT
command: run
ports:
- "3000:8080"
links:
- db-author:db
environment:
- INSTANCE_TYPE=author
- DB_TYPE=postgresql
- DB_ADDRESS=db
- DB_PORT=5432
- DB_SCHEMA=magnolia
- DB_USERNAME=magnolia
- DB_PASSWORD=mysecretpassword
Create a new container for
the database
Create a network link between
the database and magnolia
Create another container for Magnolia
Configure the instance as an author
and to use the postgresql driver
Thanks to the link, we don’t have to specify the
database IP address

26. … TO PROD
๏ Use a full Docker stack
- Reuse the same Docker Compose definition
- If the architectures are slightly different use extends keyword
- Use Docker Swarm to deploy on multiple hosts
- Use Docker Machine to provision the hosts
๏ But, wait, Docker Compose/Swarm are still in Beta
- Use Kubernetes if you want a cluster with dynamic provisioning and hosts allocation
- Use Ansible if you want static hosts provisioning and allocation (see my blog post*)
๏ In all cases use the same Docker Images !
* http://nicolasbarbe.com/2015/07/13/magnolia-devops-automate-deployment/

27. SERVICE DISCOVERY
Build a Service Registry to let Magnolia discovers the services automatically
The Service Registry
- Defines microservices in a YAML file
- Discovers the services through
environment variables, Java system
properties, from the JCR or by value
- Injects services in the templates
- Provides a generic connector to
build dedicated content apps in
YAML
services:
questions:
connection:
host: QUESTIONS_QUERIES_HOST
port: QUESTIONS_QUERIES_PORT
type: env
apiVersion: v1
resource:
name: question
properties:
- name: id
type: Integer
- name: title
type: String
- name: description
https://github.com/nicolasbarbe/magnolia-http-utils

28. DISPLAYING CONTENT
[#assign id=ctx.getParameter("id")]
[#assign question=httpfn.service("question").GET(id)]
<div class="row">
<h2>${question.title}</h2>
<h4>${question.initiator}</h4>
<p class="lead">
${question.description}
</p>
<div class="pull-right">Asked ${question.createdAt?datetime?date}</div>
</div>

29. MANAGING CONTENT
Presenters uses
Query side
Actions connect to the
Command side

30. HTTPS://GITHUB.COM/NICOLASBARBE/MAGNOLIA-ASK

31. QUESTIONS?