Add Support for Microsoft.Extensions.Diagnostics.IHealthCheck?

[Aaronontheweb]

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

We have a couple of different implementations for health-checks floating around in Akka.NET - all of them expressing the same idea: let the platform supervisor (i.e. Kubernetes, Cloud, process monitor etc) know when the Akka.NET service is degraded as a result of common problems:

• Inability to join cluster;
• Akka.Persistence being unavailable;
• Failure to start ActorSystem (i.e. an Akka.Remote port binding failure.)

The first implementation is one I rolled myself a few years ago - and it works well enough: https://github.com/petabridge/akkadotnet-healthcheck - however, it definitely suffers from byte rot to some degree and there isn't a "one liner" way of integrating it with something like ASP.NET.

The second implementation, which is not fully baked as far as I know, is inside Akka.Management's HTTP APIs: https://github.com/akkadotnet/Akka.Management/tree/dev/src/management/Akka.Management#exposed-rest-api-endpoints - this takes a hard dependency on ASP.NET and you basically have to ship your Akka.NET application with a lightweight HTTP API on top of it. Plus, I don't think those checks are configurable beyond whether or not a cluster has been formed.

Describe the solution you'd like

Micrsoft.Extensions.Diagnostics.IHealthCheck provides a somewhat standard way of plugging healthcheck infrastructure together through the HealthCheckService class. Since Akka.Hosting is already built around the Microsoft.Extensions.[DI|Hosting|Configuration] libraries anyway, why not support having pluggable healthchecks from services like Akka.Management or Akka.Persistence available as options on the builder interface here?

Describe alternatives you've considered

Making Akka.Management the end-all-be-all for this.

[Aaronontheweb]

cc @Arkatufus

[Arkatufus]

It is technically the same thing as the health check inside Akka.Management but with a better interface and integration with ASP.NET. It will still need a web API to be accessed from the outside world.

[Aaronontheweb]

Ah, this is why? https://docs.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.builder.healthcheckendpointroutebuilderextensions.maphealthchecks?view=aspnetcore-6.0

We have to expose a route for it?

[Arkatufus]

Well, the interface itself is only a contract for it to be called by the HealthCheck service. The service itself will hook itself into a route in ASP.NET.
https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/health-checks?view=aspnetcore-6.0#use-health-checks-routing

[Aaronontheweb]

Yeah by the looks of it - it all appears to be very ASP.NET-centric

[Aaronontheweb]

So end to end delivery is going to be the end-users' problem - we're not going to implement the healthcheck services for them, only register the Akka.NET IHealthCheck implementations.

"How do I expose this data to Kubernetes / {insert hosting option here}?" - "not our problem" and provide them with a link to the standard MSFT documentation on the subject

[wesselkranenborg]

@Aaronontheweb: is this something which is already being worked on? We want to have the Akka.Persistence and Akka.Cluster parts of https://github.com/petabridge/akkadotnet-healthcheck wrapped in an IHealthCheck (we will wire it up ourselves as we need to combine it with a lot of other healthchecks also). Just a question to see if anything here is in progress, not that we build it ourselves and then after a few days you have built it also 😀.

[Aaronontheweb]

Not actively being worked on at the moment, but something we would like to do!

[wesselkranenborg]

Example implementation for support for IHealthCheck together with Akka.HealthCheck is made here: petabridge/akkadotnet-healthcheck#146

[Arkatufus]

Draft for IHealthCheck integration: petabridge/akkadotnet-healthcheck#148

[Arkatufus]

Resolved by petabridge/akkadotnet-healthcheck#148