Kotlin Application Deployment Checklist

Kotlin Application Deployment Checklist

Kotlin JVM applications share many deployment concerns with Java but have unique considerations. Here's your production checklist.

Build Configuration

// build.gradle.kts
tasks.withType<Jar> {
    manifest {
        attributes["Main-Class"] = "com.example.ApplicationKt"
    }
}

tasks.register<Jar>("fatJar") {
    archiveClassifier.set("all")
    duplicatesStrategy = DuplicatesStrategy.EXCLUDE
    from(configurations.runtimeClasspath.get().map { if (it.isDirectory) it else zipTree(it) })
    with(tasks.jar.get())
}

• [ ] Fat JAR or layered Docker build configured
• [ ] ProGuard/R8 configured for size optimization (if applicable)
• [ ] Kotlin version matches all dependencies

JVM Tuning

java -Xms512m -Xmx2g \
  -XX:+UseG1GC \
  -XX:MaxGCPauseMillis=200 \
  -XX:+UseContainerSupport \
  -jar app-all.jar

• [ ] Heap size configured (-Xms and -Xmx)
• [ ] Container-aware JVM flags enabled
• [ ] GC algorithm selected for workload type

Coroutine Configuration

// Use appropriate dispatchers
val dbDispatcher = Dispatchers.IO.limitedParallelism(20)
val cpuDispatcher = Dispatchers.Default

// Install exception handler
val handler = CoroutineExceptionHandler { _, exception ->
    logger.error("Unhandled coroutine exception", exception)
}

val scope = CoroutineScope(SupervisorJob() + handler)

• [ ] Coroutine exception handlers installed
• [ ] Dispatchers configured for workload types
• [ ] SupervisorJob used for independent child coroutines

Health and Monitoring

routing {
    get("/health") {
        val dbHealthy = checkDatabase()
        val status = if (dbHealthy) HttpStatusCode.OK else HttpStatusCode.ServiceUnavailable
        call.respond(status, mapOf("status" to if (dbHealthy) "healthy" else "degraded"))
    }
}

• [ ] Health endpoint checks all dependencies
• [ ] Structured logging with kotlin-logging
• [ ] Error tracking with Bugsly for exception visibility
• [ ] Metrics endpoint for monitoring

Container Setup

FROM eclipse-temurin:21-jre-alpine
COPY build/libs/app-all.jar /app.jar
EXPOSE 8080
ENTRYPOINT ["java", "-jar", "/app.jar"]

• [ ] Minimal base image (JRE, not JDK)
• [ ] Non-root user configured
• [ ] Graceful shutdown handles SIGTERM