I want to use healthchecks and Serilog (with request logging), but I get a flood of useless log events, as well as ones for the failure cases.
The v8 docs (and this) show there are differences between UseHealthChecks and MapHealthChecks. I prefer the latter (which is the recommended option as per the docs).
I think the middleware order must be the problem. What is the correct order?
I found some guidance here, here and here.
Apparently when using MapHealthChecks one cannot simply rely on the position of the middleware in the pipeline; one must also use short-circuiting.
The middleware pipeline should be configured in this order:
// must be before serilog so not logged
app.UseStaticFiles();
// must be before healthchecks, so can use `ShortCircuit`
app.UseRouting();
// can be before serilog...
app.MapHealthChecks("/healthz")
.ShortCircuit(); // prevents double-logging healthcheck errors
app.UseSerilogRequestLogging();
// ...or after serilog
//app.MapHealthChecks("/healthz").ShortCircuit();
// other middleware...
// lastly (though could move auth upward if needed)
app.UseAuthentication();
app.UseAuthorization();
app.MapRazorPages();
app.MapControllers();
Failed healthcheck in Development:
[2024-12-02T08:01:29.307Z+00:00 DBG Microsoft.Extensions.Diagnostics.HealthChecks.DefaultHealthCheckService] Running health checks
[2024-12-02T08:01:29.308Z+00:00 DBG Microsoft.Extensions.Diagnostics.HealthChecks.DefaultHealthCheckService] Running health check Default
[2024-12-02T08:01:29.309Z+00:00 ERR Microsoft.Extensions.Diagnostics.HealthChecks.DefaultHealthCheckService] Health check Default with status Unhealthy completed after 0.0941ms with message 'null'
[2024-12-02T08:01:29.310Z+00:00 DBG Microsoft.Extensions.Diagnostics.HealthChecks.DefaultHealthCheckService] Health check processing with combined status Unhealthy completed after 2.5307ms
Failed healthcheck in Production:
[2024-12-02T07:34:15.879Z+00:00 ERR Microsoft.Extensions.Diagnostics.HealthChecks.DefaultHealthCheckService] Health check Default with status Unhealthy completed after 0.8362ms with message 'null'
Successful healthcheck in Development:
[2024-12-02T07:28:42.124Z+00:00 DBG Microsoft.Extensions.Diagnostics.HealthChecks.DefaultHealthCheckService] Running health checks
[2024-12-02T07:28:42.137Z+00:00 DBG Microsoft.Extensions.Diagnostics.HealthChecks.DefaultHealthCheckService] Running health check Default
[2024-12-02T07:28:42.145Z+00:00 DBG Microsoft.Extensions.Diagnostics.HealthChecks.DefaultHealthCheckService] Health check Default with status Healthy completed after 2.2999ms with message 'null'
[2024-12-02T07:28:42.167Z+00:00 DBG Microsoft.Extensions.Diagnostics.HealthChecks.DefaultHealthCheckService] Health check processing with combined status Healthy completed after 38.1864ms
Successful healthcheck in Production: there should be no log entries.