Running complex project setups with Testcontainers
In a lot of my #testing content, I’ve been showing how to run projects locally, for example by using Docker containers. In this video, I’m showing how to build up a complex project setup using Testcontainers, while keeping a flexible and efficient development workflow.
My goal is to separate the life cycles of my system / acceptance tests from the test environment’s life cycle, in order to allow for quick turnarounds and to re-use my test scenarios in different scopes. In this way, this shows how to build up what I’d consider a local test environment that is optimized for developer productivity.
To try it out yourself, you can find the source code on GitHub: coffee-testing
The example contains the following coffee-shop system:
The three containers (black in the picture) are started by Testcontainers, but separately from my test scenarios:
public class CoffeeShop { static Network network = Network.newNetwork(); static GenericContainer<?> barista = new GenericContainer<>("rodolpheche/wiremock:2.6.0") .withExposedPorts(8080) .waitingFor(Wait.forHttp("/__admin/")) .withNetwork(network) .withNetworkAliases("barista"); static PostgreSQLContainer<?> coffeeShopDb = new PostgreSQLContainer<>("postgres:9.5") .withExposedPorts(5432) .withDatabaseName("postgres") .withUsername("postgres") .withPassword("postgres") .withNetwork(network) .withNetworkAliases("coffee-shop-db"); static GenericContainer<?> coffeeShop = new GenericContainer<>(new ImageFromDockerfile("coffee-shop") .withDockerfile(Paths.get(System.getProperty("user.dir"), "../coffee-shop/Dockerfile"))) .withExposedPorts(8080) .waitingFor(Wait.forHttp("/q/health")) .withNetwork(network) .withNetworkAliases("coffee-shop") .dependsOn(barista, coffeeShopDb); @Test void startContainers() throws IOException { Startables.deepStart(coffeeShop, barista, coffeeShopDb).join(); String coffeeShopHost = coffeeShop.getHost(); int coffeeShopPort = coffeeShop.getMappedPort(8080); String baristaHost = barista.getHost(); int baristaPort = barista.getMappedPort(8080); writeDotEnvFile(coffeeShopHost, coffeeShopPort, baristaHost, baristaPort); String uri = "http://" + coffeeShopHost + ":" + coffeeShopPort + "/index.html"; System.out.println("The coffee-shop URLs is: " + uri); System.out.println("\nContainers started. Press any key or kill process to stop"); System.in.read(); } }
As shown in the video, you can run the example in your IDE or via the command line:
mvn -Dtest=com.sebastian_daschner.coffee_shop.CoffeeShop test
The reason why these classes are called CoffeeShop
and CoffeeShopDev
, respectively, is that they won’t be executed via Maven Surefire per default, since they don’t contain the sequence Test
.
Network configuration
Since Testcontainers urges us to have a non-fixed setup, here with regards to port bindings, we need to reconfigure our URLs for in test scenarios and for manual access. Our test environment has been started in a separate JVM, which is why the Testcontainers code has no access as to which dynamic ports have been assigned.
We could find out the actual ports by using docker ps
or similar methods:
gt; docker ps CONTAINER ID IMAGE [...] STATUS PORTS cad0913a4787 coffee-shop:latest Up 2 seconds 0.0.0.0:49230->8080/tcp, :::49230->8080/tcp a1dd67f758e5 rodolpheche/wiremock:2.6.0 Up 19 seconds 8081/tcp, 0.0.0.0:49228->8080/tcp, :::49228->8080/tcp aa3759e70103 postgres:9.5 Up 19 seconds 0.0.0.0:49229->5432/tcp, :::49229->5432/tcp 1113ebda12b4 testcontainers/ryuk:0.3.1 Up 20 seconds 0.0.0.0:49227->8080/tcp, :::49227->8080/tcp
However, still there would be manual effort involved, to find out and configure the URLs, such as localhost:49228
, :49229
, and :49230
, each and every time. Thus, we use a way to automatically re-configure our system tests. Our CoffeeShop
class will write the port configuration into a .env
file, which will be read from our system test, via MicroProfile Config, here with Smallrye as the implementation:
Config config = ConfigProvider.getConfig(); String host = config.getValue("coffee-shop.test.host", String.class); String port = config.getValue("coffee-shop.test.port", String.class); return UriBuilder.fromUri("http://{host}:{port}/orders") .build(host, port);
The code on GitHub and the video gives you the full picture of how the URLs are configured. Per default, the values from a microprofile-config.properties
is taken, or the properties in .env
with a higher priority.
# META-INF/microprofile-config.properties coffee-shop.test.host=localhost coffee-shop.test.port=8001 barista.test.host=localhost barista.test.port=8002
# .env, written by CoffeeShop class COFFEE_SHOP_TEST_HOST=localhost COFFEE_SHOP_TEST_PORT=49230 BARISTA_TEST_HOST=localhost BARISTA_TEST_PORT=49228
This enables us to start up the environment, and use the system tests in a very fast and flexible way, as shown in the video.
Quarkus remote-dev mode
It also works to run Quarkus’ dev
mode in containers, as remote-dev
mode. My second Testcontainers example, that you find in the class CoffeeShopDev
, starts up the coffee-shop application in a way that allows to be accessed by quarkus:remote-dev
. This is really handy for us, since we don’t have to start & stop our application while we’re coding.
The CoffeeShopDev
class will output the mvn
command with the correct port, similar to:
mvn quarkus:remote-dev -Ddebug=false -Dquarkus.package.type=mutable-jar \ -Dquarkus.live-reload.url=http://localhost:49230 -Dquarkus.live-reload.password=123
Shortening the test turnaround time
As one more bonus, I’m showing how to even shorten the initialization & waiting time of our tests, by (mis-)using quarkus:dev
for our system test project, which in fact is not even a Quarkus project. This is the same approach that I’ve been showing in a previous video.
We can run the example, similar to what is shown in this video, as follows:
cd coffee-shop-st/ mvn quarkus:dev -Ptest \ -Dquarkus.test.exclude-pattern='.*\.CoffeeShop|.*\.CoffeeShopDev|.*UITest'
Trying it out yourself
You can find the source code on GitHub: coffee-testing
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Published on Java Code Geeks with permission by Sebastian Daschner, partner at our JCG program. See the original article here: Running complex project setups with Testcontainers Opinions expressed by Java Code Geeks contributors are their own. |