How to Monitor Your Ktor (Kotlin) API with Vigilmon (Free Uptime + Health Checks)

#kotlin #ktor #monitoring #uptime

How to Monitor Your Ktor (Kotlin) API with Vigilmon (Free Uptime + Health Checks)

Ktor is a lightweight Kotlin framework for building asynchronous servers and clients. If your API is running on Ktor, you need uptime monitoring to know when it goes down, when responses degrade, and when SSL certificates are close to expiring.

This guide shows you how to add a health endpoint to your Ktor app and hook it up to Vigilmon for free external monitoring.

Why External Monitoring Matters

Your internal health checks only run if your server is still running and responding. External monitoring from multiple regions catches:

The entire server going offline (no process, no check)
Network routing failures that prevent traffic from reaching you
Crashes or deadlocks that stop the Kotlin coroutine dispatcher

Step 1: Add a Health Endpoint to Your Ktor App

Add a simple /health route:

import io.ktor.server.application.*
import io.ktor.server.engine.*
import io.ktor.server.netty.*
import io.ktor.server.routing.*
import io.ktor.server.response.*
import io.ktor.http.*

fun main() {
    embeddedServer(Netty, port = 8080) {
        routing {
            get("/health") {
                call.respond(HttpStatusCode.OK, mapOf("status" to "ok"))
            }
        }
    }.start(wait = true)
}

Deploy this change and verify it responds with HTTP 200 at your domain.

Step 2: Create a Monitor in Vigilmon

Sign in at vigilmon.online and go to Monitors > New Monitor
Set URL to your health endpoint
Set Check interval: 1 minute for production APIs
Set Regions: 2-3 for multi-region consensus
Set Expected status code: 200
Save the monitor

Vigilmon starts checking your endpoint immediately.

Step 3: Configure Alerts

Go to Alert Channels and add:

Email: instant notification when the check fails
Slack: post to your ops or alerts channel
Webhook: send to PagerDuty, Discord, or any HTTP endpoint

Set escalation to alert after 2 consecutive failures to avoid false positives from transient network blips.

Step 4: Monitor SSL Certificate Expiry

Add a separate SSL certificate monitor in Vigilmon:

New Monitor > SSL Certificate
Set the domain
Alert at 30 days remaining and 7 days remaining

Advanced: Deep Health Check with Coroutines

get("/health/deep") {
    val dbOk = runCatching {
        withContext(Dispatchers.IO) { checkDatabaseConnection() }
    }.isSuccess

    call.respond(
        if (dbOk) HttpStatusCode.OK else HttpStatusCode.ServiceUnavailable,
        mapOf(
            "status" to if (dbOk) "ok" else "degraded",
            "database" to if (dbOk) "ok" else "error"
        )
    )
}