Testing different configuration of your software on the developer machine, directly from your IDE. Presented at Devoxx FR 2019 Video at https://youtu.be/0TvWv4L_IJM

1. #DevoxxFR
Functional Configuration Testing
with Docker & TestContainers
Vincent Massol @vmassol
1

2. #DevoxxFR
Use Case: XWiki
2
Application with functional tests, e.g. web app & UI tests
Database
Servlet Engine
Webapp (XWiki)
Browser
JDBCHTTP

3. #DevoxxFR
DB Type DB Version
JDBC
Driver
Servlet
E.Type
Servlet E.
Version
Browser
Type
Browser
Version
Other
5.7.24 5.1.45 8.5.35 63.0 N/A
9.6.8 42.1.4 Latest 9.x
70.0.3538.
77
Solr
External
2.4.1 2.4.1 9.4.12 60.0.2 Clustering
Latest
10.3.x
Latest
9.4.8.v201
71121
67.0.3396.
87
LibreOffice
Server
Problem: Configurations
3
Validate that XWiki works on supported configurations

4. #DevoxxFR
Docker Container #3Docker Container #2Docker Container #1
Solution: Dockerization
4
Use Docker to represent the various configurations
Database
Servlet Engine
Webapp (XWiki)
Browser

5. #DevoxxFR
Implementation 1: Jenkins
5
Dependency on CI, not able to run & debug locally
pipeline {
agent {
docker {
image 'xwiki-maven-firefox'
args '-v $HOME/.m2:/root/.m2'
}
}
stages {
stage('Test') {
steps {
docker.image('mysql:5').withRun('-e
"MYSQL_ROOT_PASSWORD=my-secret-pw"') { c ->
docker.image('tomcat:8').withRun('-v
$XWIKIDIR:/usr/local/tomcat/webapps/
xwiki').inside("--link ${c.id}:db") {
[...]

6. #DevoxxFR
Implementation 2: Maven
6
Dependency on Maven, not easy to debug in IDE
<plugin>
<groupId>io.fabric8</groupId>
<artifactId>docker-maven-plugin</artifactId>
<configuration>
<imagePullPolicy>IfNotPresent</imagePullPolicy>
<images>
[…]

7. #DevoxxFR
Implementation 3: TestContainers
7
@Testcontainers
public class MyTestcontainersTests {
@Container
private static final MySQLContainer MY_SQL_CONTAINER = new
MySQLContainer();
@Container
private PostgreSQLContainer pgsqlContainer = new PostgreSQLContainer()
.withDatabaseName("foo")
.withUsername("foo")
.withPassword("secret");
Best solution so far: Reproduce and debug locally and in IDE testcontainers.org

8. #DevoxxFR
XWiki & TestContainers
8
@UITest(
database = Database.MYSQL,
databaseTag = "5",
servletEngine = ServletEngine.TOMCAT,
servletEngineTag = "8",
browser = Browser.CHROME)
public class MenuIT
Custom JUnit5 Extension, makes it easy to use for XWiki devs
Selenium test here

9. #DevoxxFR 9
Demo Time

10. #DevoxxFR
TestContainers Features
10
• Several built-in Containers: MySQL, PostgreSQL,
Selenium/WebDriver, ElasticSearch, Nginx, and a lot
more… even a DockerCompose one!
• Automatically record videos
• Automatic and powerful clean up of containers
• Full Docker API available (uses docker-java underneath)
• Create Docker images on the fly

11. #DevoxxFR
Conclusion
11
• Very easy to reproduce/debug problems from production
• Supports about everything including Docker Outside of
Docker (DOOD)
• Consistent behavior: didn’t notice many false positives
due to the environment
Configuration Testing in your IDE
testcontainers.org