This walkthrough will explain you how to correctly create a microservice from a Ktor Template using our DevOps Console.
In order to do so, access to Mia-Platform DevOps Console, create a new project and go to the Design area.
From the Design area of your project select Microservices and then create a new one, you have now reached Mia-Platform Marketplace!
In the marketplace you will see a set of Examples and Templates that can be used to set-up microservices with a predefined and tested function.
For this walkthrough select the following example: Ktor Template.
Give your microservice the name you prefer, in this walkthrough we'll refer to it with the following name: my-ktor-service-name. Then, fill the other required fields and confirm that you want to create a microservice.
A more detailed description on how to create a Microservice can be found in Microservice from template - Get started section of Mia-Platform documentation.
In order to access to your new microservice it is necessary to create an endpoint that targets it.
In particular, in this walkthrough you will create an endpoint to your microservice my-ktor-service-name. To do so, from the Design area of your project select Endpoints and then create a new endpoint.
Now you need to choose a path for your endpoint and to connect this endpoint to your microservice. Give to your endpoint the following path: /ktor-template. Then, specify that you want to connect your endpoint to a microservice and, finally, select my-ktor-service-name.
Step 3 of Microservice from template - Get started section of Mia-Platform documentation will explain in detail how to create an endpoint from the DevOps Console.
After having created an endpoint to your microservice you should save the changes that you have done to your project in the DevOps console.
Remember to choose a meaningful title for your commit (e.g "created service my_ktor_service_name"). After some seconds you will be prompted with a popup message which confirms that you have successfully saved all your changes.
Step 4 of Microservice from template - Get started section of Mia-Platform documentation will explain how to correctly save the changes you have made on your project in the DevOps console.
Once all the changes that you have made are saved, you should deploy your project through the DevOps Console. Go to the Deploy area of the DevOps Console.
Once here select the environment and the branch you have worked on and confirm your choices clicking on the deploy button. When the deploy process is finished you will receveive a pop-up message that will inform you.
Step 5 of Microservice from template - Get started section of Mia-Platform documentation will explain in detail how to correctly deploy your project.
Now, if you copy/paste the following url in the search bar of your broser (remember to replace <YOUR_PROJECT_HOST> with the real host of your project):
https://<YOUR_PROJECT_HOST>/ktor-template/you should see a Whitelabel Error Page. This behaviour is expected since this template has no routes defined.
Wonderful! You are now ready to start customizing your service! Read next section to learn how.
Go back to Microservices, select my-ktor-service-name and access its git repository from the DevOps Console.
This is a kotlin project, in this repository you will find a directory where you can find most of the source code of the template that you have created.
We have already created the controller package to group all the files with route definitions, you can change the file structure as you prefer.
Add inside this folder directory a file named HelloWorld.kt with the following content:
package eu.miaplatform.service.controller
import io.ktor.application.Application
import com.papsign.ktor.openapigen.route.apiRouting
import com.papsign.ktor.openapigen.route.info
import com.papsign.ktor.openapigen.route.path.normal.get
import com.papsign.ktor.openapigen.route.response.respond
import com.papsign.ktor.openapigen.route.route
import com.papsign.ktor.openapigen.route.tag
import com.fasterxml.jackson.annotation.JsonProperty
import eu.miaplatform.service.model.ServiceTag
data class HelloWorldResponse (
@JsonProperty("message")
@get:JsonProperty("message")
val message: String
)
fun helloWorld(application: Application) {
application.apiRouting {
route("/") {
tag(ServiceTag) {
get<Unit, HelloWorldResponse>(
info("The description of the endpoint")
) { params ->
var response = HelloWorldResponse("Hello world!")
respond(response)
}
}
}
}
}In line respond(HelloWorldResponse("Hello world!")) you are creating an instance of a class called HelloWorld.
As you can notice we are not using the original ktor routing but the apiRouting that permits you to construct
automatically the open-api.json.`
For more details about how to use the `apiRouting see https://github.com/papsign/Ktor-OpenAPI-Generator
You have to import this file in the file inside the apiRouting installation.
import eu.miaplatform.service.controller.helloWorld
...
...
apiRouting {
//here goes your controller
helloWorld(this@module)
}
...
In this file you can see the instantiation of the library that creates the swaggers reachable at the endpoint /documentation.
After committing these changes to your repository, you can go back to Mia Platform DevOps Console.
Go to the Deploy area of the DevOps Console and deploy your project in a similar way to what you have done before modifying your git repository.
Once the deploy process is finished, go back to
https://<YOUR_PROJECT_HOST>/ktor-template/or type the following in your terminal:
curl https://<YOUR_PROJECT_HOST>/ktor-template/What you should see now is a very simple welcome message:
{"message":"Hello World!"}Congratulations! You have successfully learnt how to use our Ktor Template on the DevOps Console!