ktor-apirest-sample

This project was created using the Ktor Project Generator.

Here are some useful links to get you started:

• Ktor Documentation
• Ktor GitHub page
• The Ktor Slack chat. You'll need to request an invite to join.

Features

Here's a list of features included in this project:

Name	Description
Routing	Provides a structured routing DSL
Content Negotiation	Provides automatic content conversion according to Content-Type and Accept headers
kotlinx.serialization	Handles JSON serialization using kotlinx.serialization library
Mongo db	Enables integration with MongoDB to perform database operations within Ktor applications
Json Web Tokens	Enables secure transmission of information between parties as a JSON object, commonly used for authentication

Building & Running

Important:

To avoid exposing the connection string of our database (in this case, MongoDB), a file named local.conf has been created inside the resources/ directory. This file contains the connection string we will use. You must create this file to provide your own connection string.

mongo {
    uri = "mongodb+srv://yourUser:yourPassword@cluster1.pa7b55e.mongodb.net/"
}

The local.conf file will be used in our database class:

val config = ConfigFactory.parseResources("local.conf").resolve()
        val mongoUriLocal = config.getString("mongo.uri")
        
        val applicationConfig = ApplicationConfig("application.conf")
        val mongoUri = applicationConfig.propertyOrNull("ktor.database.uri")?.getString()?:mongoUriLocal

Or you can simply use the following:

mongoClient = MongoClient.create("your connection url to mongo db")

All of the above is intended for development mode. When deploying the application to any service in production mode, you should use the environment variable DATABASE_URL, which is configured in the application.conf file.

To do that, just leave everything like this:

val applicationConfig = ApplicationConfig("application.conf")
val mongoUri = applicationConfig.propertyOrNull("ktor.database.uri")?.getString()!!

To test the API on a cloud hosting service such as Render, simply upload the repository to the service and add the DATABASE_URL environment variable with your connection string. The Dockerfile in your application will take care of compiling everything necessary.

# Use Gradle with JDK 11 or latest to build the project
FROM gradle:8.4-jdk11 AS build
# Copy the project files into the container and set correct ownership
COPY --chown=gradle:gradle . /home/gradle/src
# Set working directory
WORKDIR /home/gradle/src
# Build the fat JAR (includes all dependencies)
RUN gradle buildFatJar --no-daemon
# Use a lightweight base image with only JDK 11 for running the app
FROM openjdk:11
# Expose port 8080 to allow external access to the application
EXPOSE 8080:8080
# Create a directory for the application
RUN mkdir /app
# Copy the fat JAR from the build container and rename it
COPY --from=build /home/gradle/src/build/libs/*.jar /app/ktor-sample-api_server.jar

# Set the entry point to run the application
ENTRYPOINT ["java","-jar","/app/ktor-sample-api_server.jar"]

Postman

This repository includes a file that can be imported into Postman and contains all the requests needed to test the API.

Please note that to perform the "get all users" request, you must first create a user and then execute the "login user" request to obtain a token.
This token should be used as a Bearer in the authorization header for protected endpoints like retrieving all users.
This allows you to properly test JWT-based authentication.

To build or run the project, use one of the following tasks:

Task	Description
./gradlew test	Run the tests
./gradlew build	Build everything
buildFatJar	Build an executable JAR of the server with all dependencies included
buildImage	Build the docker image to use with the fat JAR
publishImageToLocalRegistry	Publish the docker image locally
run	Run the server
runDocker	Run using the local docker image

If the server starts successfully, you'll see the following output:

2024-12-04 14:32:45.584 [main] INFO  Application - Application started in 0.303 seconds.
2024-12-04 14:32:45.682 [main] INFO  Application - Responding at http://0.0.0.0:8080