public static OcelotRequestDelegate BuildOcelotPipeline(this IOcelotPipelineBuilder builder, OcelotPipelineConfiguration pipelineConfiguration) { // This is registered to catch any global exceptions that are not handled // It also sets the Request Id if anything is set globally builder.UseExceptionHandlerMiddleware(); // If the request is for websockets upgrade we fork into a different pipeline builder.MapWhen(context => context.HttpContext.WebSockets.IsWebSocketRequest, app => { app.UseDownstreamRouteFinderMiddleware(); app.UseDownstreamRequestInitialiser(); app.UseLoadBalancingMiddleware(); app.UseDownstreamUrlCreatorMiddleware(); app.UseWebSocketsProxyMiddleware(); }); // Allow the user to respond with absolutely anything they want. builder.UseIfNotNull(pipelineConfiguration.PreErrorResponderMiddleware); // This is registered first so it can catch any errors and issue an appropriate response builder.UseResponderMiddleware(); // Then we get the downstream route information builder.UseDownstreamRouteFinderMiddleware(); // This security module, IP whitelist blacklist, extended security mechanism builder.UseSecurityMiddleware(); //Expand other branch pipes if (pipelineConfiguration.MapWhenOcelotPipeline != null) { foreach (var pipeline in pipelineConfiguration.MapWhenOcelotPipeline) { builder.MapWhen(pipeline); } } // Now we have the ds route we can transform headers and stuff? builder.UseHttpHeadersTransformationMiddleware(); // Initialises downstream request builder.UseDownstreamRequestInitialiser(); // We check whether the request is ratelimit, and if there is no continue processing builder.UseRateLimiting(); // This adds or updates the request id (initally we try and set this based on global config in the error handling middleware) // If anything was set at global level and we have a different setting at re route level the global stuff will be overwritten // This means you can get a scenario where you have a different request id from the first piece of middleware to the request id middleware. builder.UseRequestIdMiddleware(); // Allow pre authentication logic. The idea being people might want to run something custom before what is built in. builder.UseIfNotNull(pipelineConfiguration.PreAuthenticationMiddleware); // Now we know where the client is going to go we can authenticate them. // We allow the ocelot middleware to be overriden by whatever the // user wants if (pipelineConfiguration.AuthenticationMiddleware == null) { builder.UseAuthenticationMiddleware(); } else { builder.Use(pipelineConfiguration.AuthenticationMiddleware); } // The next thing we do is look at any claims transforms in case this is important for authorisation builder.UseClaimsToClaimsMiddleware(); // Allow pre authorisation logic. The idea being people might want to run something custom before what is built in. builder.UseIfNotNull(pipelineConfiguration.PreAuthorisationMiddleware); // Now we have authenticated and done any claims transformation we // can authorise the request // We allow the ocelot middleware to be overriden by whatever the // user wants if (pipelineConfiguration.AuthorisationMiddleware == null) { builder.UseAuthorisationMiddleware(); } else { builder.Use(pipelineConfiguration.AuthorisationMiddleware); } // Now we can run the claims to headers transformation middleware builder.UseClaimsToHeadersMiddleware(); // Allow the user to implement their own query string manipulation logic builder.UseIfNotNull(pipelineConfiguration.PreQueryStringBuilderMiddleware); // Now we can run any claims to query string transformation middleware builder.UseClaimsToQueryStringMiddleware(); builder.UseClaimsToDownstreamPathMiddleware(); // Get the load balancer for this request builder.UseLoadBalancingMiddleware(); // This takes the downstream route we retrieved earlier and replaces any placeholders with the variables that should be used builder.UseDownstreamUrlCreatorMiddleware(); // Not sure if this is the best place for this but we use the downstream url // as the basis for our cache key. builder.UseOutputCacheMiddleware(); //We fire off the request and set the response on the scoped data repo builder.UseHttpRequesterMiddleware(); return(builder.Build()); }