Health Checks - Register path/options with dependency injection

[jcoutch]

Is your feature request related to a problem? Please describe.

This feature would directly support development efforts on:
domaindrivendev/Swashbuckle.AspNetCore#1058

When adding health checks using IApplicationBuilder.UseHealthChecks, the values of path and HealthCheckOptions are only used to map HealthCheckMiddleware. After the middleware is registered, there is no way to retrieve this information at runtime.

Describe the solution you'd like

To have HealthCheckApplicationBuilderExtensions.cs refactored in a non-breaking way so that the path and HealthCheckOptions information is accessible at runtime (preferably via dependency injection).

[ghost]

We've moved this issue to the Backlog milestone. This means that it is not going to be worked on for the coming release. We will reassess the backlog following the current release and consider this item at that time. To learn more about our issue management process and to have better expectation regarding different types of issues you can read our Triage Process.

[weichch]

I'm not sure about the path, but for HealthCheckOptions, I used a workaround in my project:

var options = new HealthCheckOptions
{
    Predicate = check => check.Tags.Contains("test")
};

// Set options directly to IOptionsMonitor<HealthCheckOptions>
app.ApplicationServices
    .GetRequiredService<IOptionsMonitorCache<HealthCheckOptions>>()
    .TryAdd("my-options", options);

app.UseHealthChecks("/health", options);

Then I can access the options using dependency injection:

public MyController(IOptionsMonitor<HealthCheckOptions> optionsMonitor)
{
    var healthCheckOptions = optionsMonitor.Get("my-options");
}

Note: this doesn't mean HealthCheckOptions can be configured using the options pattern, because by the time TryAdd is called, it is unlikely you will have HealthCheckOptions already created in the cache, and there is no solid way to determine if you have registered any configuration for HealthCheckOptions in ConfigureServices.