Hello everyone. Today I am talking a few minutes for this important mission to introduce you to this fantastic project, test containers. So why I am so excited about test containers? The answer is so simple. Test containers is a framework that makes testing the dependencies of your backend application really easy. And the most important part of test containers is that everything is coded in your favorite programming language. If you want to use go, if you want to use rust or closure, test container is there for you. And of course, as the name suggests, all the dependencies are simple containers. Containers are easy to transport, containers are easy to distribute, immutable, and in fact, containers are easy to deploy. So today I'm going to show you how how to use test containers models and the sharing in the cake. I will quickly show you how to create your own test containers model. So let's go. And a big question is, what's a test containers model? So let's start with a simple test containers models Redis Redis is the world's fastest in memory database, Redis IO. About models, there are over 15 of them already created. For you to find model, go to the model section on the website just here and then select its language. Go for example. Then search for the model just here, or type just into the search bar. Sorry, Redis. As you can see, the redis model is available in several languages. For example javago.net js. Okay great. So, okay, let's go back to our code for the first time. It's time. So as you can see, I just close my terminal. As you can see, I've got a little application that lets you count the number of visitors to a webpage. And for that I have HTTP server, HTTP server here I have a root handler with my business logic to increment the counter and just get the current number and just print it. Okay, if we want to test that. Okay, it's really easy because you can run a docker container or just use docker compose. So let's go multi macfly back to the nineties with a simple contour application. So normally this application connects to my production redis instance, but I need to test the function that increment the counter. Well, it's precisely at this moment that I can use the text containers model. And just for, just for fun and to play with it. Okay, you open a terminal here, okay. And we go to the simple model just here. And after that we just run redis, sorry, Redis. Redis in background. And after that let's go for go. Run main dot go. Okay, not precisely important to build the application. And after that, okay, let's go for curl, the HTTP 323. Okay, we have a counter. Great. You have a sound like Tada. And if you cut the application, okay, I stop the application and run the application when you play with it. Let's go. You have the counter because you use a docker counter to play with application. Sorry. Okay, so good. But you know, it's not reliable to use docker. So we keep, we keep for example, redis in background and now we discover the test. So let's go to see how to use, okay, I just radius my terminal. Let's go to see how to use the redis model. Okay. To use the redis container. As you can see, it's really, really easy. Just one line, it's really good. So you can use the redis model. Redis model is here inside test containers. Test containers, go package, inside mole. And with the redis package and you can run the container just like that. So it's not necessary to precise the image, but it's just an option. After that we just get the endpoint of my redisaber to create a new client. Okay. And finally we can use the increment function, you remember the increment function here to test my redis. So, okay, this example is so trivial. No problem with that, just a tip. I used to set the counter to a value and to increment to use a 20, for example, other value. And let's go to execute this test. Oh, magic. Okay, so it's possible that I have a little bit of cash about this, this test. But as you can see, okay, we have here the port of test containers. Okay. And finally we have here just a port of my test. So, okay. And in this example, if you want, for example, if I cannot change redis for mongodB, for example, the test containers models exist. So it's really good. Okay. It was the first, very first example. So let's go for most advanced example. Okay, I just keep the first example here. Sorry, just here, keep my guru inside my first example. Okay, close, close. Okay. Just keep this terminal. I will explain what I want to keep this part of my simple model in my advanced, other model. I want to show you just here the main function. Exactly and precisely the same case as the first. But in this case we use an HTTP call to increment my counter. For example, the advance is the second microservice. To use the first simple microservice. Okay, why use this example for you today? Is just because I want to demonstrate another amazing project and its name is microx. Microx is awesome. Microx is here, just here in the test. So I will explain. I have an HTTP server here with root handler here and I use the increment here. So just in this case I print number of visitors with just a number or the error because you call another server. In this demonstration, as you can see, I call the previous. So if I test this second advanced model, I can curl it with 4444. I'm sorry, I'm sorry. I just go run the main, let's go. And finally I change directory for this and I can curl here. And as you can see, we use the previous model as a microservice. Okay, so it's a big, big, big problem because if you have for example 20 microservices, it's really difficult to run all around the world. So in my example I will use the amazing microx model just here. The idea of microx is to create, to put in place a contract testing between your microservices and to keep up to date using for example openapi. So in my test data here, I have the description of my API. So it's not a trivial description because in this example counter API, I have a root path and I have a simple counter here. But the magic here is that I use like a script to generate the increment. Okay? So it's like a mock. And this URL for example is the same as microx. So for example, my test, I create, I use the microx container here, okay. I use the package, this good package testify to, to ensure that I don't have any error here. Finally I import as a main artifact. So I let you discover my crux about that to define my, finally my API. So in fact my mock about API, I get the endpoint of microcs and I will use the rest mock endpoint to have the ability to play with the mock. And finally I use increment with this mock a first time and a second time to be sure that my increment function as really great. So let's go. And if I run the test, as you can see, it's okay, it's okay. So really good to demonstrate the ability to use this amazing project. Okay, so Julian, two amazing project in one video. Yeah, because in the day to day of software engineering, you have to use the precious software, the precious tools. And I think that test containers and microcs are two of best in my set. Okay, so really easy to use as you can see. So now let's go to create our own test container. Okay. And the first question is how to create my own test containers models. What's next? Now it's time to create your own container. Okay. Since for me it's late and I have a little imagination, we're going to create an Nginx model, okay? So let's go. And to create a model, it's very, very simple. Okay, let's go. To create a model, you just declare a go package with a primary function like run container. Okay. It's more like a convention. It's more like a convention. Here you're running always the context is used to create your container and some customizers. So some options about. So in this example we have a first container request. After that we use image property and we can declare exposed ports property. And you have a lot of option to say to test container. Okay, the container is ready, the container restart. So after that you create a generic request. And here you can use started with value to true to say. Okay, start now. Because if you want to prepare, for example, you can create a run container without the started true. But if your model's users use it without started, the model is not started. So easy. After that you can create a generic container. And as you can see, it's really easy inside test containers to use the generic containers. You know, it's not precisely important to, you don't need, in fact, to create all containers. You can use just vanilla test containers with generators, generic containers. In this example, I use the example of the official website of test containers to retrieve the host and to get the map port. In our case, it's this port here and to put the URI inside the destruction. Yeah, easy to use for the rest of this demonstration. So here, for example, you can create some options and in my case, I use with index, with auth file index to replace the default index of NgInX. Okay. And test containers is very, is very cool in fact, because you have all the sets about, about you need. For example, if you want to put files inside the containers, if you want to map some ports, etc. Etc. So, okay, we have our first model, okay, in your imagination you can use this model with this full path. For example, go get blah blah blah blah blah model nginx. Okay. But in our case we use a test file to demonstrate how to use this. Let's go to see our test. This test is a test run container, okay, basic. And we just run the function run container, sorry, with a specific index. My index is really, really good because you have inside just conv. 42, okay. I'm sorry, I closed the test. We check that we don't have no error. We check also the cleanup of the container. And finally we fetch the value of nginx to be sure that it's equal to con 42. So, okay, I just put this comment here. The value con 42 comes from test data index HTML. And I use a tiny function, fetch to get the nginx server. Okay, let's go to run the tests. Okay, so if you want to practice like BDD or other things like that. My first error was here. As you can see, it's okay. We have a bad test. Okay, I just put the initial value. Okay. So like we said, et voila. Know you know how to use test container very quickly. If you'd like more information about test containers, please don't hesitate to get in touch with the community. They are really nice. I'd also like to thank them for this lovely t shirt and in fact, this amazing technology. Because I think that in the software engineering, this is precisely a tool, a missing tool. But now it's good to have test containers. And one more serious note, don't hesitate to simply test your go applications. It's really important and very easy. And now you can use a bunch of tools about AI. So see you next time for new adventure. And really happy to have you today.