Logging

For logging what is happening on routing infrastructure, you can create a KtorSimpleLogger instance and pass to the routing instance:

internal val LOGGER = KtorSimpleLogger("com.example.application")

val router = routing(logger = LOGGER) {
    handle("/hello") {
        // Handle any call to the "/hello" route
    }
}

• On JVM, KtorSimpleLogger uses SLF4J API as a facade for various logging frameworks (for example, Logback or Log4j) and allows you to log application events. To enable logging, you need to add dependencies for the desired framework and provide configuration specific for this framework.

You can also install and configure the CallLogging plugin to log route requests.

• For others KtorSimpleLogger provides a logger that prints everything to the standard output.

More info about setup Logging can be found in the origin docs here.

Access logger in code

The Logger instance is represented by a class that implements the Logger interface. You can access the Logger instance inside the Application using the Application.logger property. For example, the code snippet below shows how to add a message to a log inside the module.

import dev.programadorthi.routing.core.application
// ...

val router = routing(logger = LOGGER) {
    application.logger?.info("Hello from Kotlin Routing!")
    // ...
}

You can also access the Logger from ApplicationCall using the call.application.environment.log property.

import dev.programadorthi.routing.core.application.application
// ...

val router = routing(logger = LOGGER) {
    handle("/hello") {
        application.logger?.info("Hello from /hello!")
    }
}

Call logging plugin

The CallLogging plugin allows you to log incoming route requests.

Add dependencies

sourceSets {
    commonMain.dependencies {
        implementation("dev.programadorthi.routing:call-logging:$version")
    }
}

Install CallLogging

val router = routing(logger = LOGGER) {
    install(CallLogging)
    // ...
}

Set the logging level

By default, it uses the CallLevel.INFO logging level. To change it, use the level property:

val router = routing(logger = LOGGER) {
    install(CallLogging) {
        level = CallLevel.DEBUG
    }
    // ...
}

Filter log requests

The filter property allows you to add conditions for filtering requests. In the example below, only requests made to /home/profile get into a log:

val router = routing(logger = LOGGER) {
    install(CallLogging) {
        filter { call ->
            call.path().startsWith("/home/profile")
        }
    }
    // ...
}

Customize a log message format

By using the format function, you can put any data related to a route into a log. The example below shows how to log a route method, a name, a URI, and the parameters value to each route.

val router = routing(logger = LOGGER) {
    install(CallLogging) {
        format { call ->
            "Method: ${call.routeMethod}, name: ${call.name}, uri: ${call.uri}, parameters: ${call.parameters.toMap()}"
        }
    }
    // ...
}

Important

There is an embedded support to MDC (Mapped Diagnostic Context) by default but it hasn't been tested yet