Serilog sending blank CorrelationId to Seq logger - .net-core

I'm using Serilog and Seq in a .net core web api to handle the logging. I've added a reference to Steve Gordon's CorrelationId Middleware to get the X-Correlation-ID from the headers (or create a new one) to update the TraceIdentifier.
I've then added another middleware class to push the correlation id into the log context, but this isn't working correctly:
public class LogCorrelationIdMiddleware
{
private readonly RequestDelegate _next;
public LogCorrelationIdMiddleware(RequestDelegate next)
{
_next = next;
}
public Task Invoke(HttpContext context)
{
// doesn't work - blank CorrelationId in Seq
using (LogContext.PushProperty("CorrelationId", context.Request.HttpContext.TraceIdentifier)) { return _next(context); }
// works - correct CorrelationId2 in Seq
//using (LogContext.PushProperty("CorrelationId2", context.Request.HttpContext.TraceIdentifier)) { return _next(context); }
}
}
Any ideas why?

It's working for me when I do the following (not as middleware):
using (LogContext.PushProperty("CorrelationId", "This is a test..."))
{
Log.Write(level, exception, messageTemplate, propertyValues);
}
So I suspect that it's your CorrelationId being overwritten by ASP.NET Core MVC as eluded to here:
https://github.com/serilog/serilog-aspnetcore/issues/59
Some background to the issue and their plan to deal with it in 3.0 is also here:
https://github.com/aspnet/AspNetCore/issues/5918
Apologies that this isn't a "fix", however I had the same issue and was able to work around it by adding a level of indirection between the log call (in my code) and the call to Log.Write (as shown above).

Related

Consume OpenApi client .NET Core with Interface

Someone out there must have run into this already...
I created a WebApi solution with swagger implemented, full documentation, the whole 9 yards!
When I run my web api solution, see the swagger output (and I've tested the endpoints, all working fine)
I can see the swagger definition: https://localhost:5001/swagger/v1/swagger.json
Now, I want to consume this Api as a connected service on my web app.
So following every single tutorial online:
I go to my webapp
right click on Connected Services
Add Connected Service
Add Service Reference > OpenApi > add Url, namespace & class name
That generates a partial class in my solution (MyTestApiClient)
public parial class MyTestApiClient
{
// auto generated code
}
Next step, inject the service in Startup.cs
services.AddTransient(x =>
{
var client = new MyTestApiClient("https://localhost:5001", new HttpClient());
return client;
});
Then, inject the class into some class where it's consumed and this all works
public class TestService
{
private readonly MyTestApiClient _client; // this is class, not an interface -> my problem
public TestService(MyTestApiClient client)
{
_client = client;
}
public async Task<int> GetCountAsync()
{
return _client.GetCountAsync();
}
}
So everything up to here works. BUT, this generated OpenApi client doesn't have an interface which sucks for the purposes of DI and Unit Testing.
I got around this by creating a local interface IMyTestApiClient, added to the generated class (MyTestApiClient). I only have 1 endpoint in my WebApi so have to declare that on my interface.
public parial class MyTestApiClient : IMyTestApiClient
{
// auto generated code
}
public interface IMyTestApiClient
{
// implemented in generated MyTestApiClient class
Task<int> GetCountAsync();
}
services.AddTransient<IMyTestApiClient, MyTestApiClient>(x =>
{
IMyTestApiClient client = new MyTestApiClient("https://localhost:5001", new HttpClient());
return client;
});
public class TestService
{
private readonly IMyTestApiClient _client; // now injecting local interface instead of the generated class - great success
public TestService(IMyTestApiClient client)
{
_client = client;
}
public async Task<int> GetCountAsync()
{
return _client.GetCountAsync();
}
}
But this is a bad approach because it makes me manually create an interface and explicitly declare the methods I want to consume. Furthermore, every time my Api gets updated, I will have to tweak my local interface.
So question time:
How can I add an OpenApi Service Reference that automagically also generates an interface as well?
Thanks in advance for any help getting to a viable solution.
You may have already found the answer but I had the same issue and managed to resolve it by adding /GenerateClientInterfaces:true in the Options section for the OpenAPI reference in my .csproj:
<OpenApiReference Include="api.json" CodeGenerator="NSwagCSharp" Namespace="MyNamespace" ClassName="MyClassName">
<SourceUri>https://localhost:7040/swagger/v1/swagger.json</SourceUri>
<OutputPath>MyClient.cs</OutputPath>
<Options>/GenerateClientInterfaces:true</Options>
</OpenApiReference>

How to make application insights ignore cancel

Gives a 500 response code when the cancel button is pressed multiple types by the users.
Not causing performance issues but just a lot of clutter in application insights.
Any way to filter this out would be helpful.
Nothing is shown in the telemetry to share too, only the API method that is been called with a 500 code and time. sharing the screenshot of that.
Since you know the response code is 500, you can use telemetry processor to filter out these kinds of request with code 500.
Assume you're using .NET core, you can follow the steps below:
Create a class which implements ITelemetryProcessor, then filter out the request whose response code is 500(or more conditions as per your need.). The sample code looks like below:
public class IgnoreCancelFilter : ITelemetryProcessor
{
private ITelemetryProcessor Next { get; set; }
// next will point to the next TelemetryProcessor in the chain.
public IgnoreCancelFilter(ITelemetryProcessor next)
{
this.Next = next;
}
public void Process(ITelemetry item)
{
var request = item as RequestTelemetry;
if (request != null &&
request.ResponseCode.Equals("500", StringComparison.OrdinalIgnoreCase))
{
// To filter out an item, return without calling the next processor.
return;
}
// Send everything else
this.Next.Process(item);
}
}
Then, register it in ConfigureServices method of your Startup.cs class.
public void ConfigureServices(IServiceCollection services)
{
// ...
services.AddApplicationInsightsTelemetry();
services.AddApplicationInsightsTelemetryProcessor<IgnoreCancelFilter>();
}
If the programming language is not .NET core, you can find the proper method for .NET framework / js etc. in this article.

What is the entry point for adding code to Blazor?

I need to add some code to a Blazor WASM app that run as the application is starting up. I want to make a call to an API to get some settings to use during the rest of the application's lifetime.
I have verified that the API is configured correctly and that it returns data.
I've tried adding both MainLayout.razor.cs as well as App.razor.cs in order to make the call.
Neither of these worked. However when I add the SAME code to one of my other components (below), it works fine.
public class ViewMenuModel : ComponentBase
{
[Inject] HttpClient Http { get; set; }
[Inject] AppState AppState { get; set; }
protected override async Task OnInitializedAsync()
{
Settings = await Http.GetJsonAsync<List<Settings>>("settings");
UpdateSettings(Settings);
}
protected void UpdateSettings(List<Settings> settings)
{
AppState.SetSettings(settings);
}
}
Is it possible that I'm just missing something? Is this kind of thing supposed to work from either MainLayout or App?? If so, what's the trick?
It's been some time since I asked this question initially, but I think it might be valuable for future people....
When I started, I think we were on .Net core 3.1, since then, migrating to .net 6, there's actual Microsoft documentation on how to add these types of configurations
https://learn.microsoft.com/en-us/aspnet/core/blazor/fundamentals/configuration?view=aspnetcore-6.0
In Program.cs
var http = new HttpClient()
{
BaseAddress = new Uri(builder.HostEnvironment.BaseAddress)
};
builder.Services.AddScoped(sp => http);
using var response = await http.GetAsync("cars.json");
using var stream = await response.Content.ReadAsStreamAsync();
builder.Configuration.AddJsonStream(stream);

TelemetryProcessor - Multiple instances overwrite Custom Properties

I have a very basic http-POST triggered api which creates a TelemetryClient. I needed to provide a custom property in this telemetry for each individual request, so I implemented a TelemtryProcessor.
However, when subsequent POST requests are handled and a new TelemetryClient is created that seems to interfere with the first request. I end up seeing maybe a dozen or so entries in App Insights containing the first customPropertyId, and close to 500 for the second, when in reality the number should be split evenly. It seems as though the creation of the 2nd TelemetryClient somehow interferes with the first.
Basic code is below, if anyone has any insight (no pun intended) as to why this might occur, I would greatly appreciate it.
ApiController which handles the POST request:
public class TestApiController : ApiController
{
public HttpResponseMessage Post([FromBody]RequestInput request)
{
try
{
Task.Run(() => ProcessRequest(request));
return Request.CreateResponse(HttpStatusCode.OK);
}
catch (Exception)
{
return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, Constants.GenericErrorMessage);
}
}
private async void ProcessRequest(RequestInput request)
{
string customPropertyId = request.customPropertyId;
//trace handler creates the TelemetryClient for custom property
CustomTelemetryProcessor handler = new CustomTelemetryProcessor(customPropertyId);
//etc.....
}
}
CustomTelemetryProcessor which creates the TelemetryClient:
public class CustomTelemetryProcessor
{
private readonly string _customPropertyId;
private readonly TelemetryClient _telemetryClient;
public CustomTelemetryProcessor(string customPropertyId)
{
_customPropertyId = customPropertyId;
var builder = TelemetryConfiguration.Active.TelemetryProcessorChainBuilder;
builder.Use((next) => new TelemetryProcessor(next, _customPropertyId));
builder.Build();
_telemetryClient = new TelemetryClient();
}
}
TelemetryProcessor:
public class TelemetryProcessor : ITelemetryProcessor
{
private string CustomPropertyId { get; }
private ITelemetryProcessor Next { get; set; }
// Link processors to each other in a chain.
public TelemetryProcessor(ITelemetryProcessor next, string customPropertyId)
{
CustomPropertyId = customPropertyId;
Next = next;
}
public void Process(ITelemetry item)
{
if (!item.Context.Properties.ContainsKey("CustomPropertyId"))
{
item.Context.Properties.Add("CustomPropertyId", CustomPropertyId);
}
else
{
item.Context.Properties["CustomPropertyId"] = CustomPropertyId;
}
Next.Process(item);
}
}
It's better to avoid creating Telemetry Client per each request, isntead re-use single static Telemetry Client instance. Telemetry Processors and/or Telemetry Initializers should also typically be registered only once for the telemetry pipeline and not for every request. TelemetryConfiguration.Active is static and by adding new Processor with each request the queue of processor only grows.
The appropriate setup would be to add Telemetry Initializer (Telemetry Processors are typically used for filtering and Initializers for data enrichment) once into the telemetry pipeline, e.g. though adding an entry to ApplicationInsights.config file (if present) or via code on TelemetryConfiguration.Active somewhere in global.asax, e.g. Application_Start:
TelemetryConfiguration.Active.TelemetryInitializers.Add(new MyTelemetryInitializer());
Initializers are executed in the same context/thread where Track..(..) was called / telemetry was created, so they will have access to the thread local storage and or local objects to read parameters/values from.

In ASP.NET 5, how do I get the chosen route in middleware?

I am building an ASP.NET 5 (vNext) site that will host dynamic pages, static content, and a REST Web API. I have found examples of how to create middleware using the new ASP.NET way of doing things but I hit a snag.
I am trying write my own authentication middleware. I would like to create a custom attribute to attach to the controller actions (or whole controllers) that specifies that it requires authentication. Then during a request, in my middleware, I would like to cross reference the list of actions that require authentication with the action that applies to this current request. It is my understanding that I configure my middleware before the MVC middleware so that it is called first in the pipeline. I need to do this so the authentication is done before the request is handled by the MVC controller so that I can't prevent the controller from ever being called if necessary. But doesn't this also mean that the MVC router hasn't determined my route yet? It appears to me the determination of the route and the execution of that routes action happen at one step in the pipeline right?
If I want to be able to determine if a request matches a controller's action in a middleware pipeline step that happens before the request is handled by the controller, am I going to have to write my own url parser to figure that out? Is there some way to get at the routing data for the request before it is actually handled by the controller?
Edit: I'm beginning to think that the RouterMiddleware might be the answer I'm looking for. I'm assuming I can figure out how to have my router pick up the same routes that the standard MVC router is using (I use attribute routing) and have my router (really authenticator) mark the request as not handled when it succeeds authentication so that the default mvc router does the actual request handling. I really don't want to fully implement all of what the MVC middleware is doing. Working on trying to figure it out. RouterMiddleware kind of shows me what I need to do I think.
Edit 2: Here is a template for the middleware in ASP.NET 5
public class TokenAuthentication
{
private readonly RequestDelegate _next;
public TokenAuthentication(RequestDelegate next)
{
_next = next;
}
public async Task Invoke(HttpContext context)
{
//do stuff here
//let next thing in the pipeline go
await _next(context);
//do exit code
}
}
I ended up looking through the ASP.NET source code (because it is open source now!) and found that I could copy the UseMvc extension method from this class and swap out the default handler for my own.
public static class TokenAuthenticationExtensions
{
public static IApplicationBuilder UseTokenAuthentication(this IApplicationBuilder app, Action<IRouteBuilder> configureRoutes)
{
var routes = new RouteBuilder
{
DefaultHandler = new TokenRouteHandler(),
ServiceProvider = app.ApplicationServices
};
configureRoutes(routes);
routes.Routes.Insert(0, AttributeRouting.CreateAttributeMegaRoute(
routes.DefaultHandler,
app.ApplicationServices));
return app.UseRouter(routes.Build());
}
}
Then you create your own version of this class. In my case I don't actually want to invoke the actions. I will let the typical Mvc middleware do that. Since that is the case I gut all the related code and kept just what I needed to get the route data which is in actionDescriptor variable. I probably can remove the code dealing with backing up the route data since I dont think what I will be doing will affect the data, but I have kept it in the example. This is the skeleton of what I will start with based on the mvc route handler.
public class TokenRouteHandler : IRouter
{
private IActionSelector _actionSelector;
public VirtualPathData GetVirtualPath(VirtualPathContext context)
{
EnsureServices(context.Context);
context.IsBound = _actionSelector.HasValidAction(context);
return null;
}
public async Task RouteAsync(RouteContext context)
{
var services = context.HttpContext.RequestServices;
EnsureServices(context.HttpContext);
var actionDescriptor = await _actionSelector.SelectAsync(context);
if (actionDescriptor == null)
{
return;
}
var oldRouteData = context.RouteData;
var newRouteData = new RouteData(oldRouteData);
if (actionDescriptor.RouteValueDefaults != null)
{
foreach (var kvp in actionDescriptor.RouteValueDefaults)
{
if (!newRouteData.Values.ContainsKey(kvp.Key))
{
newRouteData.Values.Add(kvp.Key, kvp.Value);
}
}
}
try
{
context.RouteData = newRouteData;
//Authentication code will go here <-----------
var authenticated = true;
if (!authenticated)
{
context.IsHandled = true;
}
}
finally
{
if (!context.IsHandled)
{
context.RouteData = oldRouteData;
}
}
}
private void EnsureServices(HttpContext context)
{
if (_actionSelector == null)
{
_actionSelector = context.RequestServices.GetRequiredService<IActionSelector>();
}
}
}
And finally, in the Startup.cs file's Configure method at the end of the pipeline I have it setup so that I use the same routing setup (I use attribute routing) for the both my token authentication and mvc router.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
//Other middleware delcartions here <----------------
Action<IRouteBuilder> routeBuilder = routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
};
app.UseTokenAuthentication(routeBuilder);
//Middleware after this point will be blocked if authentication fails by having the TokenRouteHandler setting context.IsHandled to true
app.UseMvc(routeBuilder);
}
Edit 1:
I should also note that at the moment I am not concerned about the extra time required to select the route twice which is what I think would happen here since both my middleware and the Mvc middleware will be doing that. If that becomes a performance problem then I will build the mvc and authentication in to one handler. That would be best idea performance-wise, but what I have shown here is the most modular approach I think.
Edit 2:
In the end to get the information I needed I had to cast the ActionDescriptor to a ControllerActionDescriptor. I am not sure what other types of actions you can have in ASP.NET but I am pretty sure all my action descriptors should be ControllerActionDescriptors. Maybe the old legacy Web Api stuff needs another type of ActionDescriptor.

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