Primitives and APIs for declaring and triggering cronjobs with webhooks.
At Turkish Technic, we have tens of development teams, each tasked with a number of projects. Many applications we develop need a periodic nudge to perform tasks in the background.
This package provides us with the primitives necessary to define, manage, and trigger them in a central application.
Install TT.Cronjobs.AspNetCore package
dotnet add package TT.Cronjobs.AspNetCoreThen implement ICronjob interface, and add [Cron] attribute. There's only one method you need to
implement: ExecuteAsync. This method gets called when the cronjob gets triggered.
[Cron("1 * * * *")] // every hour
public class CreateHourlyReport : ICronjob
{
private readonly ILogger<CreateHourlyReport> _logger;
private readonly AppDbContext _db;
public CreateHourlyReport(ILogger<CreateReport> logger, AppDbContext db)
{
_logger = logger;
_db = db;
}
public async Task ExecuteAsync(CancellationToken cancellationToken)
{
_logger.LogInformation("creating report...");
await Task.Delay(TimeSpan.FromSeconds(10), cancellationToken);
var sum = _db.Sales.Sum(s => s.Total);
_logger.LogInformation($"created report. sum = {sum}");
}
}Register necessary services in Startup.cs.
public void ConfigureServices(IServiceCollection services) {
services.AddCronjobs();
services.AddTransient<CreateHourlyReport>();
// ...
}AddCronjobs() extension method registers a background service that calls RegistrationApi with the list of cronjobs
defined in the assembly. This service then sends a POST request to our application at intervals defined in [Cron]
attribute. (This service is not included in this project)
Define an endpoint for webhooks:
public void Configure(IApplicationBuilder app)
{
// ...
app.UseEndpoints(endpoints =>
{
endpoints.MapCronjobWebhook("/-/cronjobs");
// ...
});
}For configuration you can supply a delegate to services.AddCronjobs(), or define it in appsettings.json
// services.Configure<CronjobsOptions>(Configuration.GetSection(CronjobsOptions.Key));
services.AddCronjobs(options => {});{
"Cronjobs": {
"RegistrationApiUrl": "https://cronjobs.app.turkishtechnic.com",
"UrlTemplate": "https://my.app/-/cronjobs/{name}"
}
}Webhook URLs are generated using UrlTemplate option. Here we mapped the webhook URL as /-/cronjobs, and configured
an absolute URL template. This means you can trigger a webhook with
https://my.app/-/cronjobs/createhourlyreport (case-insensitive).
Other options you can define:
public class CronjobsOptions
{
public const string Key = "Cronjobs";
public string RegistrationApiUrl { get; set; }
public string UrlTemplate { get; set; }
public int RetryCount { get; set; } = 5;
public int WaitSeconds { get; set; } = 5;
public int TimeoutSeconds { get; set; } = 60;
}