As presented at PHPCon Poland 2016 It's a situation many of us are familiar with: a large legacy application, limited or no tests, slow & manual release process, low velocity, no confidence.... Oh, and management wants new features, fast. But how to proceed? Using examples and lessons learned from a real-world case, I'll show you how to strangle the legacy application with a modern service architecture and build a continuous deployment pipeline to deliver value from the first sprint. On the way, we take a look at testing strategies and various (possibly controversial!) tips and best practices.

1. THE ROAD TO CONTINUOUS
DEPLOYMENT - A CASE STUDY
MICHIEL ROOK - @MICHIELTCS

2. ▸ Java, PHP & Scala developer
▸ Consultant, trainer, speaker
▸ make.io
▸ Dutch Web Alliance
▸ Maintainer of Phing
▸ @michieltcs

3. THIS TALK
▸ Background
▸ The approach
▸ Process / standards
▸ Build pipelines
▸ Results & lessons learned

5. THE SYSTEM - SAN DIEGO
▸ ... or the Big Ball Of Mud
▸ Large legacy monolith
▸ Generates significant income
▸ Slow & complex
▸ Technical debt

6. SAN DIEGO
FRONTEND
MYSQL
DB
SAN DIEGO
BACKEND
LOAD BALANCERS / VARNISH
ITBANEN INTERMEDIAIR NATIONALEVACATUREBANK
SAN DIEGO
FRONTEND
SAN DIEGO
FRONTEND
SAN DIEGO
FRONTEND
SAN DIEGO
BACKEND
SAN DIEGO
BACKEND
SAN DIEGO
BACKEND
MEMCACHE FTP
EXT.
SERVICES
SOLR

7. THE SYSTEM - SAN DIEGO
▸ Infrequent, manual releases
▸ Fragile tests
▸ Low velocity
▸ Frequent outages / bugs / issues
▸ Frustrated team
▸ Low confidence modifying existing code

8. GOALS
▸ Reduce issues
▸ Reduce cycle time
▸ Increase productivity
▸ Increase motivation

9. REFACTOR? REBUILD?

10. APPROACH
▸ Strangler pattern
▸ Services per domain object
(job, jobseeker, ...)
▸ Proxy to switch between
old/new
▸ Migrate individual pages

11. ORIGINAL
MONOLITH
PROXY
SERVICE
ORIGINAL
MONOLITH
ORIGINAL
MONOLITH
SERVICE SERVICE
SERVICE
PROXY
DB
DB
DB
DB
DB DB

12. APPROACH
▸ Services behind load balancers
▸ Access legacy db’s
▸ Continuous deployment
▸ Docker containers
▸ Frontends are services

13. SAN DIEGO
ELASTIC
SEARCHLEGACY
DB
JOB
SERVICE
RMQ
ITBANEN INTERMEDIAIR NATIONALEVACATUREBANK
MONGO
DB
ITBANEN
JOBSEEKER
SERVICE
NVBINTERMEDIAIR

14. PROCESS

15. STARTING OFF
▸ Scrum, 1 week sprints
▸ TDD / BDD
▸ Definition of Done
▸ Team mindset / experience
▸ Focus on value
▸ Replace old features with new (legacy becomes obsolete)

16. CONTINUOUS EVERYTHING

17. DEV BUILD / TEST
CONTINUOUS INTEGRATION

18. DEV BUILD / TEST ACCEPTANCE PRODUCTION
CONTINUOUS DELIVERY

19. DEV BUILD / TEST ACCEPTANCE PRODUCTION
CONTINUOUS DEPLOYMENT

20. WHY CONTINUOUS DEPLOYMENT
▸ Small steps
▸ Less overhead
▸ Early feedback
▸ Reduce cycle time
▸ Reduce risk

21. ONLY COMMIT TO MASTER

22. NO BRANCHES

23. NO BRANCHES
REALLY.

24. PAIR PROGRAMMING

25. BOY SCOUT RULE

26. QUALITY GATES

27. 100% CODE COVERAGE*

28. FEATURE TOGGLES, A/B TESTS

29. DEVOPS

30. DASHBOARDS

31. BUILD
PIPELINE

32. AUTOMATE REPEATABLE THINGS

33. EVERY COMMIT GOES TO
PRODUCTION

34. DEFENSE IN DEPTH
UNIT TESTS
INTEGRATION
TESTS
ACCEPTANCE
TESTS
UI TESTS

35. DEFENSE IN DEPTH
UNIT TESTS
INTEGRATION
TESTS
ACCEPTANCE
UI TESTS
public function testJobCannotBeFound() {
$jobRepository = $this->prophesize(JobRepository::class);
$jobRepository->getById(EXPECTED_JOB_ID)
->shouldBeCalled()
->willReturn(false);
$jobService = new JobService($jobRepository->reveal());
$this->assertFalse($jobService->getById(EXPECTED_JOB_ID));
}

36. DEFENSE IN DEPTH
UNIT TESTS
INTEGRATION
TESTS
ACCEPTANCE
TESTS
UI TESTS
public function testFindJob() {
$expectedJob = $this->loadFixture('active_job.yml');
$actualJob = $this->repository->getById($expectedJob->getId());
self::assertInstanceOf(Job::class, $actualJob);
self::assertEquals($expectedJob->getId(), $actualJob->getId());
}

37. DEFENSE IN DEPTH
UNIT TESTS
INTEGRATION
TESTS
ACCEPTANCE
TESTS
UI TESTSScenario: Link to related job
Given a job exists
And there are related jobs available
When that job is viewed
Then a list of related jobs is shown
And each related job links to the detail page of the related job

38. DEFENSE IN DEPTH
UNIT TESTS
INTEGRATION
TESTS
ACCEPTANCE
TESTS
UI TESTS

39. DEFENSE IN DEPTH
MANUAL
TESTING?
UNIT TESTS
INTEGRATION
TESTS
ACCEPTANCE
TESTS
UI

40. CONTINUOUS TESTING
UNIT TESTS
INTEGRATION TESTS
ACCEPTANCE TESTS
UI TESTS
SMOKE
TESTS
Cost Speed
Exploratory
testing
Monitoring

41. PIPELINE AS CODE
node {
stage 'Run tests'
sh "phpunit"
sh "behat"
stage 'Build docker image'
sh "phing build"
sh "docker build -t jobservice:${env.BUILD_NUMBER} ."
sh "docker push jobservice:${env.BUILD_NUMBER}"
stage 'Deploy acceptance'
sh "ansible-playbook -e BUILD=${env.BUILD_NUMBER}
-i acc deploy.yml"
stage 'Deploy production'
sh "ansible-playbook -e BUILD=${env.BUILD_NUMBER}
-i prod deploy.yml"
}

42. DOCKERFILE
FROM php:7.0-apache
ADD vhost.conf /etc/apache2/sites-available/000-default.conf
ADD . /var/www/html

43. DEPLOYING
PULL IMAGE
START NEW CONTAINER
WAIT FOR PORT
SMOKE TESTS / HEALTH CHECKS
ADD NEW CONTAINER TO LB
REMOVE OLD CONTAINER FROM LB
STOP OLD CONTAINER

44. DEPLOYING
PULL IMAGE
START NEW CONTAINER
WAIT FOR PORT
SMOKE TESTS / HEALTH CHECKS
ADD NEW CONTAINER TO LB
REMOVE OLD CONTAINER FROM LB
STOP OLD CONTAINER
docker pull

45. DEPLOYING
PULL IMAGE
START NEW CONTAINER
WAIT FOR PORT
SMOKE TESTS / HEALTH CHECKS
ADD NEW CONTAINER TO LB
REMOVE OLD CONTAINER FROM LB
STOP OLD CONTAINER
docker run

46. DEPLOYING
PULL IMAGE
START NEW CONTAINER
WAIT FOR PORT
SMOKE TESTS / HEALTH CHECKS
ADD NEW CONTAINER TO LB
REMOVE OLD CONTAINER FROM LB
STOP OLD CONTAINER
wait_for: port=8080 delay=5 timeout=15

47. DEPLOYING
PULL IMAGE
START NEW CONTAINER
WAIT FOR PORT
SMOKE TESTS / HEALTH CHECKS
ADD NEW CONTAINER TO LB
REMOVE OLD CONTAINER FROM LB
STOP OLD CONTAINER
uri:
url: http://localhost:8080/_health
status_code: 200
timeout: 30

48. DEPLOYING
PULL IMAGE
START NEW CONTAINER
WAIT FOR PORT
SMOKE TESTS / HEALTH CHECKS
ADD NEW CONTAINER TO LB
REMOVE OLD CONTAINER FROM LB
STOP OLD CONTAINER
template: src=haproxy.cfg.j2
dest=/etc/haproxy/haproxy.cfg
service: name=haproxy state=reloaded

49. DEPLOYING
PULL IMAGE
START NEW CONTAINER
WAIT FOR PORT
SMOKE TESTS / HEALTH CHECKS
ADD NEW CONTAINER TO LB
REMOVE OLD CONTAINER FROM LB
STOP OLD CONTAINER
template: src=haproxy.cfg.j2
dest=/etc/haproxy/haproxy.cfg
service: name=haproxy state=reloaded

50. DEPLOYING
PULL IMAGE
START NEW CONTAINER
WAIT FOR PORT
SMOKE TESTS / HEALTH CHECKS
ADD NEW CONTAINER TO LB
REMOVE OLD CONTAINER FROM LB
STOP OLD CONTAINER
docker stop
docker rm

51. BUILD PIPELINE

52. FEEDBACK!

53. RESULTS

54. RESULTS
▸ Total build time per service < 10 minutes
▸ Significantly improved page load times
▸ Improved audience stats (time on page, pages per session,
session duration, traffic, seo ranking, etc)
▸ Increased confidence and velocity
▸ Experimented with new tech/stacks (angular, jvm, event
sourcing)
▸ More fun

55. LESSONS LEARNED
▸ Team acceptance
▸ Change is hard
▸ Overhead of weekly sprint; requires discipline
▸ Docker orchestration
▸ Issues with traffic between Amazon <-> on-premise
datacenter
▸ Javascript testing

56. LESSONS LEARNED
▸ Experience with new tech
▸ Stability of build pipelines
▸ Management/leadership buy-in
▸ Business alignment
▸ Not enough focus on replacing legacy application

57. QUESTION TIME

58. THANK YOU!
@michieltcs / michiel@make.io