Upgrade to 3.1 produces empty ocelot.json

[mkanakis]

Expected Behavior

In .NET Core 2.2, inside the Startup constructor we have the following configuration:

var builder = new ConfigurationBuilder().SetBasePath(env.ContentRootPath);

if (env.IsLocal())
{
  builder.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);
} else
{
   builder.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true);
}
builder.AddEnvironmentVariables();

 // Loads corresponding folder -> e.g. Products/Local/*.json
var gateway = System.Environment.GetEnvironmentVariable("ASPNETCORE_GATEWAY");
builder.AddOcelot($"/{gateway}/{env.EnvironmentName}/", env);

Configuration = builder.Build();
Environment = env;

In ConfigureServices we use the following line to add Ocelot as a middleware:

services.AddOcelot(Configuration);

As you can see, we specify a certain path for merging ocelot files for different environments.

After upgrading to .NET Core 3.1 the only difference is in Configure method:

app.UseRouting();

app.UseCors("CorsPolicy"); // to remove

app.UseAuthentication();

app.UseEndpoints(endpoints =>
{
    endpoints.MapControllers();
});

app.UseOcelot().Wait();

The above snippets should merge all ocelot.*.json files into ocelot.json and work as intended. At least with 2.2 that was the case.

Actual Behavior

In 3.1, the generated ocelot.json is empty! So every request leads to => 404

One thing I noticed is in this line:

builder.AddOcelot(string, env);

It used to get the ContentRootPath and add the rest {gateway}/{env.name}.
Instead, it goes to "C:/" now. I fixed this by adding the ContentRootPath in front, but still the generated routing config is empty.

Produced ocelot.json:

{"Routes":[],"DynamicRoutes":[],"Aggregates":[],"GlobalConfiguration":{"RequestIdKey":null,"ServiceDiscoveryProvider":{"Scheme":null,"Host":null,"Port":0,"Type":null,"Token":null,"ConfigurationKey":null,"PollingInterval":0,"Namespace":null},"RateLimitOptions":{"ClientIdHeader":"ClientId","QuotaExceededMessage":null,"RateLimitCounterPrefix":"ocelot","DisableRateLimitHeaders":false,"HttpStatusCode":429},"QoSOptions":{"ExceptionsAllowedBeforeBreaking":0,"DurationOfBreak":0,"TimeoutValue":0},"BaseUrl":"http://localhost:56512","LoadBalancerOptions":{"Type":null,"Key":null,"Expiry":0},"DownstreamScheme":null,"HttpHandlerOptions":{"AllowAutoRedirect":false,"UseCookieContainer":false,"UseTracing":false,"UseProxy":true,"MaxConnectionsPerServer":2147483647},"DownstreamHttpVersion":null}}

Specifications

• Version: Ocelot 16.0.1
• Platform: .NET Core 3.1

[mkanakis]

Update:

If I downgrade Ocelot to latest 15 version (v15.0.7), the configuration (ocelot.json) is back again, with .NET Core 3.1.

So narrowing down the problem, the empty configuration only occurs in: v16.0.0 & v16.0.1

[Mato-01]

Thank you for sharing, i spent a lot of time resolving this bug

[amweiss]

I've also found the 16 versions have an issue where it seems to break JWT authentication. Running 15.0.7 everything was fine. If I upgrade to 16.0.x and rename "ReRoutes" to "Routes" in the appsettings.json, the basic routes seem ok but when I inspect the Identity in the context it's not translating claims correctly. I don't have a simple case to post yet, but it seems like there's a step missing for the config upgrade or something is very broken.

[ediblecode]

It looks like this is caused by this method:

Ocelot/src/Ocelot/DependencyInjection/ConfigurationBuilderExtensions.cs

Line 37 in 3ef6abd

public static IConfigurationBuilder AddOcelot(this IConfigurationBuilder builder, string folder, IWebHostEnvironment env)

And specifically by this line:

Ocelot/src/Ocelot/DependencyInjection/ConfigurationBuilderExtensions.cs

Line 78 in 3ef6abd

File.WriteAllText(primaryConfigFile, json);

I followed the config from this answer for .NET Core 3.1. But did the following instead:

-config.AddOcelot("your folder", hostingContext.HostingEnvironment);
+config.AddJsonFile($"ocelot.{hostingContext.HostingEnvironment.EnvironmentName}.json", true, true);

So avoiding the call to AddOcelot avoids the ocelot.json file being overwritten.

But according to the docs:

The way Ocelot merges the files is basically load them, loop over them, add any Routes, add any AggregateRoutes and if the file is called ocelot.global.json add the GlobalConfiguration aswell as any Routes or AggregateRoutes. Ocelot will then save the merged configuration to a file called ocelot.json and this will be used as the source of truth while ocelot is running.

So it looks like it's by design and not a bug!

[raman-m]

@mkanakis Hi Marios!
Thanks for your interest in Ocelot!

I see you fought with Ocelot config files for different environments.
I believe linked PR 1569 will help you much.

[raman-m]

@mkanakis

In .NET Core 2.2, inside the Startup constructor we have the following configuration:

Specifications

• Version: Ocelot 16.0.1
• Platform: .NET Core 3.1

We don't support .NET Core 3.x since 16.0.2 release.
Current version is .NET 7 with Ocelot 19.0.x releases.

If the issue still persists, please open new issue/PRs.