Why doesn't Ocelot.Provider.Kubernetes work?

[tuannh6495]

Both Ocelot API and Price API are running on K8s
There are my source code for Ocelot

packages

<PackageReference Include="Ocelot" />
<PackageReference Include="Ocelot.Provider.Kubernetes" />

Program.cs

using Ocelot.DependencyInjection;
using Ocelot.Middleware;
using Ocelot.Provider.Kubernetes;

var builder = WebApplication.CreateBuilder(args);

builder.Configuration
    .AddJsonFile("ocelot.json", optional: false, reloadOnChange: true)
    .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
    .AddEnvironmentVariables();
builder.Services.AddOcelot()
    .AddKubernetes();

var app = builder.Build();
app.UseOcelot().Wait();
app.Run();

ocelot.json

{
  "Routes": [
    {
      "Servicename": "price-webapi",
      "DownstreamPathTemplate": "/api/price/{everything}",
      "UpstreamPathTemplate": "/api/price/{everything}",
      "UpstreamHttpMethod": [ "GET", "POST", "PUT", "DELETE" ],
      "UseServiceDiscovery": true,
      "LoadBalancerOptions": {
        "Type": "RoundRobin"
      }
    }
  ],
  "GlobalConfiguration": {
    "ServiceDiscoveryProvider": {
      "Type": "Kube",
      "Namespace": "cafef-dev1"
    }
  }
}

When I use url from ocelot to route to price-api, I got this error:

[05:33:59 WRN] requestId: 0HN8FDP0KCCDL:00000001, previousRequestId: No PreviousRequestId, message: 'Ocelot Retry strategy for the operation of 'System.Func`1[System.Threading.Tasks.Task`1[KubeClient.Models.EndpointsV1]]' type -> Retry No 1: The predicate has identified erroneous state in the returned result. For further details, implement logging of the result's value or properties within the predicate method.'
[05:33:59 WRN] requestId: 0HN8FDP0KCCDL:00000001, previousRequestId: No PreviousRequestId, message: 'Ocelot Retry strategy for the operation of 'System.Func`1[System.Threading.Tasks.Task`1[KubeClient.Models.EndpointsV1]]' type -> Retry No 2: The predicate has identified erroneous state in the returned result. For further details, implement logging of the result's value or properties within the predicate method.'
[05:33:59 WRN] requestId: 0HN8FDP0KCCDL:00000001, previousRequestId: No PreviousRequestId, message: 'Kube provider. Namespace:cafef-dev1, Service:price-webapi; Unable to use bad result returned by Kube integration endpoint because the final result is invalid/unknown after multiple retries!'
[05:33:59 WRN] requestId: 0HN8FDP0KCCDL:00000001, previousRequestId: No PreviousRequestId, message: 'Error Code: ServicesAreEmptyError Message: There were no services in RoundRobin for 'price-webapi' during LeaseAsync operation! errors found in ResponderMiddleware. Setting error response for request path:/api/price/v1/values, request method: GET'
[05:33:59 INF] Request finished HTTP/1.1 GET http://10.5.45.161:31901/api/price/v1/values - 404 0 null 2147.6126ms

I checked in ocelot api's pod with:

curl http://price-webapi.cafef-dev1.svc.cluster.local:9100/api/price/v1/values

and got success result.

Please help me fix this issue!
Thanks a lot!

[raman-m]

What's your full name?
What are the links to your social networks?

[raman-m]

Please answer, my dear friend from China!

[tuannh6495]

Hi @raman-m !
If you have any solution, please give it on here!

[raman-m]

Read below plz! 👇

[raman-m]

Our extension package is based on KubeClient one.

`message: 'Error Code: ServicesAreEmptyError Message: There were no services in RoundRobin for 'price-webapi' during LeaseAsync operation! errors found in ResponderMiddleware. Setting error response for request path:/api/price/v1/values, request method: GET'

This error means that Kube client either can't connect to the k8s service or it's not configured at all.

If you don't use Pod service then configuration is injected here, and you have to define JSON settings in appsettings.json:

Ocelot/src/Ocelot.Provider.Kubernetes/OcelotBuilderExtensions.cs

Line 31 in 2e352bc

KubeClientOptions options = sp.GetRequiredService<IOptions<KubeClientOptions>>().Value;

If you use Pod service, then it is responsible for connection to the cluster. Please read more instructions in KubeClient documentation!

Hope it helps!

[tuannh6495]

Thanks for your answer!
I checked request "http://10.5.45.161:31901/api/price/v1/values" from apigateway pod with curl cmd (token ca.crt)
With the result, I know the problem is come from K8s cluster binding. I updated it, it worked!

[raman-m]

Congrats! 🎉