Health Checks

Healthchecks are crucial when it comes to complex backend setups. They allow you to monitor the health of your application and ensure that it is running smoothly. Most of the time, a health check is a simple endpoint that returns a status code indicating whether the application is healthy or not.

Serinus provides the HealthCheckModule, which allows you to easily create health check endpoints for your application.

Getting Started

To get started with health checks in Serinus, you nbeed to install the serinus_health_checks package:

dart pub add serinus_health_checks

Setting up a Health Check

An health check represents a summary of health indicators. A health indicators executes a check of a server to determine if it is healthy or not. serinus_health_checks provides a set of built-in health indicators, such as:

• MemoryHealthIndicator: checks the memory usage of the application.
• DiskHealthIndicator: checks the disk usage of the application.
• HttpPingIndicator: checks the availability of an HTTP endpoint.
• LoxiaHealthIndicator: checks the connectivity to a database through loxia.

To get start with your health checks, you can add the HealthCheckModule to your Serinus application and configure it with the desired health indicators. For example:

import 'package:serinus/serinus.dart';
import 'package:serinus_health_checks/serinus_health_checks.dart';

class AppModule extends Module {
  AppModule()
	: super(
		imports: [
		  HealthCheckModule(
			indicators: [
			  MemoryHealthIndicator(),
			  DiskHealthIndicator(),
			  HttpPingIndicator('example', 'https://example.com'),
			],
		  ),
		],
		controllers: [AppController()],
	  );
}

In this example, we have added three health indicators: MemoryHealthIndicator, DiskHealthIndicator, and HttpPingIndicator. The HttpPingIndicator checks the availability of the https://example.com endpoint.

Custom Health Indicators

In some cases the provided health indicators may not be sufficient for your needs. In such cases, you can create your own custom health indicators by implementing the HealthIndicator interface. For example:

import 'package:serinus_health_checks/serinus_health_checks.dart';

class CustomHealthIndicator implements HealthIndicator {
  @override
  Future<HealthIndicatorCheck> pingCheck() async {
	// Perform your custom health check logic here
	final isHealthy = await performCustomCheck();

	return (
		status: isHealth ? HealthStatus.up : HealthStatus.down,
		details: {'custom': 'Custom health check result'},
	);
  }
}

In this example, we have created a custom health indicator called CustomHealthIndicator. The pingCheck method contains the logic for performing the health check and returns a HealthIndicatorCheck record that indicates whether the application is healthy or not, along with any additional details.