Migrating API Gateway from Ocelot to YARP
This guide provides guidance for migrating your existing microservice application's API Gateway from Ocelot to YARP. Since YARP is available with ABP v8.0+, you will need to update your existing application in order to apply YARP changes.
History
Until this version, ABP Commercial was using the Ocelot for the API Gateway, in the Microservice Startup Template. Since the Ocelot library is not actively maintained, we have searched for an alternative and decided to switch from Ocelot to YARP for the API Gateway. YARP is maintained by Microsoft and is actively being developed and seems a better alternative than Ocelot and provides the same feature stack and even more.
YARP Migration Steps
You should update various files in different projects to upgrade your the API Gateway from Ocelot to YARP. All of the required changes are listed below in different sections, please apply the following steps to upgrade from Ocelot to YARP.
Alternatively, you can create a Microservice Startup Template and compare your changes with the microservice template. It's recommended approach to ensure all the required changes have been done.
Shared Hosting Gateways Project
- Remove the Ocelot packages and add YARPpackages as follows:
    <ItemGroup>
-        <PackageReference Include="Ocelot" Version="17.0.0" />
-        <PackageReference Include="Ocelot.Provider.Polly" Version="17.0.0" />
+        <PackageReference Include="Yarp.ReverseProxy" Version="2.0.0" />
    </ItemGroup>
- Open the *SharedHostingGatewaysModule.csand make the following changes:
    public override void ConfigureServices(ServiceConfigurationContext context)
    {
        var configuration = context.Services.GetConfiguration();
        var env = context.Services.GetHostingEnvironment();
-      var ocelotBuilder = context.Services.AddOcelot(configuration)
-           .AddPolly();
-       if (!env.IsProduction())
-       {
-           ocelotBuilder.AddDelegatingHandler<AbpRemoveCsrfCookieHandler>(true);
-       }
+       context.Services.AddReverseProxy()
+           .LoadFromConfig(configuration.GetSection("ReverseProxy"));
    }
- Update the GatewayHostBuilderExtensions.csfile as follows:
using Microsoft.Extensions.Configuration;
namespace Microsoft.Extensions.Hosting;
public static class AbpHostingHostBuilderExtensions
{
    public const string AppYarpJsonPath = "yarp.json";
    public static IHostBuilder AddYarpJson(
        this IHostBuilder hostBuilder,
        bool optional = true,
        bool reloadOnChange = true,
        string path = AppYarpJsonPath)
    {
        return hostBuilder.ConfigureAppConfiguration((_, builder) =>
        {
            builder.AddJsonFile(
                path: AppYarpJsonPath,
                optional: optional,
                reloadOnChange: reloadOnChange
            );
        });
    }
}
- Delete the OcelotConfiguration.csfile from the solution.
Public Web Gateway Project
- Remove the ocelot.json file and instead create a new yarp.json file and update its content as follows (in the root directory of the PublicWebGatewayproject):
{
  "ReverseProxy": {
    "Routes": {
      "AbpApi": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/abp/{**catch-all}"
        }
      },
      "AdministrationSwagger": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/swagger-json/Administration/swagger/v1/swagger.json"
        },
        "Transforms": [
          {
            "PathRemovePrefix": "/swagger-json/Administration"
          }
        ]
      },
      "Account": {
        "ClusterId": "AuthServer",
        "Match": {
          "Path": "/api/account/{**catch-all}"
        }
      },
      "AuthServerSwagger": {
        "ClusterId": "AuthServer",
        "Match": {
          "Path": "/swagger-json/AuthServer/swagger/v1/swagger.json"
        },
        "Transforms": [
          {
            "PathRemovePrefix": "/swagger-json/AuthServer"
          }
        ]
      },
      "Product": {
        "ClusterId": "Product",
        "Match": {
          "Path": "/api/product-service/{**catch-all}"
        }
      },
      "ProductSwagger": {
        "ClusterId": "Product",
        "Match": {
          "Path": "/swagger-json/Product/swagger/v1/swagger.json"
        },
        "Transforms": [
          {
            "PathRemovePrefix": "/swagger-json/Product"
          }
        ]
      }
    },
    "Clusters": {
      "AuthServer": {
        "Destinations": {
          "AuthServer": {
            "Address": "https://localhost:44322/"
          }
        }
      },
      "Administration": {
        "Destinations": {
          "Administration": {
            "Address": "https://localhost:44367/"
          }
        }
      },
      "Product": {
        "Destinations": {
          "Product": {
            "Address": "https://localhost:44361/"
          }
        }
      }
    }
  }
}
- Open the Program.csfile and make the following changes:
    builder.Host
        .AddAppSettingsSecretsJson()
-       .AddOcelotJson()
+       .AddYarpJson() 
        .UseAutofac()
        .UseSerilog();
- Open the module class of the PublicWebGatewayproject and update theOnApplicationInitializationmethod as follows:
+   using Yarp.ReverseProxy.Configuration;
    
    //other configurations...
    
    public override void OnApplicationInitialization(ApplicationInitializationContext context)
    {
        var app = context.GetApplicationBuilder();
        var env = context.GetEnvironment();
        var configuration = context.GetConfiguration();
+       var proxyConfig = app.ApplicationServices.GetRequiredService<IProxyConfigProvider>().GetConfig();
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        app.UseCorrelationId();
        app.UseStaticFiles();
+       app.UseCors();
+       app.UseRouting();
+       app.UseAuthorization();
        app.UseSwagger();
+       app.UseAbpSwaggerUI(options => { ConfigureSwaggerUI(proxyConfig, options, configuration); });
        app.UseAbpSerilogEnrichers();
+       app.UseRewriter(CreateSwaggerRewriteOptions());
        app.UseEndpoints(endpoints => endpoints.MapReverseProxy());
    }
+    private static void ConfigureSwaggerUI(
+        IProxyConfig proxyConfig,
+        SwaggerUIOptions options,
+        IConfiguration configuration)
+    {
+        foreach (var cluster in proxyConfig.Clusters)
+        {
+            options.SwaggerEndpoint($"/swagger-json/{cluster.ClusterId}/swagger/v1/swagger.json", $"{cluster.ClusterId} API");
+        }
+        options.OAuthClientId(configuration["AuthServer:SwaggerClientId"]);
+        options.OAuthScopes(
+            "AdministrationService",
+            "AccountService",
+            "ProductService"
+        );
+    }
+    private static RewriteOptions CreateSwaggerRewriteOptions()
+    {
+        var rewriteOptions = new RewriteOptions();
+        rewriteOptions.AddRedirect("^(|\\|\\s+)$", "/swagger"); // Regex for "/" and "" (whitespace)
+        return rewriteOptions;
+    }
Web Gateway Project
- Remove the ocelot.json file and instead create a new yarp.json file and update its content as follows (in the root directory of the WebGatewayproject):
{
  "ReverseProxy": {
    "Routes": {
      "AbpApi": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/abp/{**catch-all}"
        }
      },
      "SettingManagement": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/setting-management/{**catch-all}"
        }
      },
      "FeatureManagement": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/feature-management/{**catch-all}"
        }
      },
      "PermissionManagement": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/permission-management/{**catch-all}"
        }
      },
      "AuditLogging": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/audit-logging/{**catch-all}"
        }
      },
      "LanguageManagement": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/language-management/{**catch-all}"
        }
      },
      "TextTemplateManagement": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/text-template-management/{**catch-all}"
        }
      },
      "LeptonThemeManagement": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/lepton-theme-management/{**catch-all}"
        }
      },
      "GDPR": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/api/gdpr/{**catch-all}"
        }
      },
      "AdministrationSwagger": {
        "ClusterId": "Administration",
        "Match": {
          "Path": "/swagger-json/Administration/swagger/v1/swagger.json"
        },
        "Transforms": [
          { "PathRemovePrefix": "/swagger-json/Administration" }
        ]
      },
      "Account": {
        "ClusterId": "AuthServer",
        "Match": {
          "Path": "/api/account/{**catch-all}"
        }
      },
      "AccountAdmin": {
        "ClusterId": "AuthServer",
        "Match": {
          "Path": "/api/account-admin/{**catch-all}"
        }
      },
      "AuthServerSwagger": {
        "ClusterId": "AuthServer",
        "Match": {
          "Path": "/swagger-json/AuthServer/swagger/v1/swagger.json"
        },
        "Transforms": [
          { "PathRemovePrefix": "/swagger-json/AuthServer" }
        ]
      },
      "Identity": {
        "ClusterId": "Identity",
        "Match": {
          "Path": "/api/identity/{**catch-all}"
        }
      },
      "OpenIddict": {
        "ClusterId": "Identity",
        "Match": {
          "Path": "/api/openiddict/{**catch-all}"
        }
      },
      "IdentitySwagger": {
        "ClusterId": "Identity",
        "Match": {
          "Path": "/swagger-json/Identity/swagger/v1/swagger.json"
        },
        "Transforms": [
          { "PathRemovePrefix": "/swagger-json/Identity" }
        ]
      },
      "Saas": {
        "ClusterId": "Saas",
        "Match": {
          "Path": "/api/saas/{**catch-all}"
        }
      },
      "Payment": {
        "ClusterId": "Saas",
        "Match": {
          "Path": "/api/payment/{**catch-all}"
        }
      },
      "PaymentAdmin": {
        "ClusterId": "Saas",
        "Match": {
          "Path": "/api/payment-admin/{**catch-all}"
        }
      },
      "SaasSwagger": {
        "ClusterId": "Saas",
        "Match": {
          "Path": "/swagger-json/Saas/swagger/v1/swagger.json"
        },
        "Transforms": [
          { "PathRemovePrefix": "/swagger-json/Saas" }
        ]
      },
      "Product": {
        "ClusterId": "Product",
        "Match": {
          "Path": "/api/product-service/{**catch-all}"
        }
      },
      "ProductSwagger": {
        "ClusterId": "Product",
        "Match": {
          "Path": "/swagger-json/Product/swagger/v1/swagger.json"
        },
        "Transforms": [
          { "PathRemovePrefix": "/swagger-json/Product" }
        ]
      }
    },
    "Clusters": {
      "AuthServer": {
        "Destinations": {
          "AuthServer": {
            "Address": "https://localhost:44322/"
          }
        }
      },
      "Administration": {
        "Destinations": {
          "Administration": {
            "Address": "https://localhost:44367/"
          }
        }
      },
      "Identity": {
        "Destinations": {
          "Identity": {
            "Address": "https://localhost:44388/"
          }
        }
      },
      "Saas": {
        "Destinations": {
          "Saas": {
            "Address": "https://localhost:44381/"
          }
        }
      },
      "Product": {
        "Destinations": {
          "Product": {
            "Address": "https://localhost:44361/"
          }
        }
      }
    }
  }
}
- Open the Program.csfile and make the change in the below:
    builder.Host
        .AddAppSettingsSecretsJson()
-       .AddOcelotJson()
+       .AddYarpJson() 
        .UseAutofac()
        .UseSerilog();
- Open the module class of the WebGatewayproject and update theOnApplicationInitializationmethod as follows:
+   using Yarp.ReverseProxy.Configuration;
    
    //other configurations...
    
    public override void OnApplicationInitialization(ApplicationInitializationContext context)
    {
        var app = context.GetApplicationBuilder();
        var env = context.GetEnvironment();
        var configuration = context.GetConfiguration();
+       var proxyConfig = app.ApplicationServices.GetRequiredService<IProxyConfigProvider>().GetConfig();
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        app.UseCorrelationId();
        app.UseStaticFiles();
+       app.UseCors();
+       app.UseRouting();
+       app.UseAuthorization();
        app.UseSwagger();
+       app.UseAbpSwaggerUI(options => { ConfigureSwaggerUI(proxyConfig, options, configuration); });
        app.UseAbpSerilogEnrichers();
+       app.UseRewriter(CreateSwaggerRewriteOptions());
        app.UseEndpoints(endpoints => endpoints.MapReverseProxy());
    }
+    private static void ConfigureSwaggerUI(
+        IProxyConfig proxyConfig,
+        SwaggerUIOptions options,
+        IConfiguration configuration)
+    {
+        foreach (var cluster in proxyConfig.Clusters)
+        {
+            options.SwaggerEndpoint($"/swagger-json/{cluster.ClusterId}/swagger/v1/swagger.json", $"{cluster.ClusterId} API");
+        }
+        options.OAuthClientId(configuration["AuthServer:SwaggerClientId"]);
+        options.OAuthScopes(
+            "AdministrationService",
+            "AccountService",
+            "IdentityService",
+            "SaasService",
+            "ProductService"
+        );
+    }
+    private static RewriteOptions CreateSwaggerRewriteOptions()
+    {
+        var rewriteOptions = new RewriteOptions();
+        rewriteOptions.AddRedirect("^(|\\|\\s+)$", "/swagger"); // Regex for "/" and "" (whitespace)
+        return rewriteOptions;
+    }
Chart Updates
- Update the gateway-web-public-configmap.yamlas follows (etc/k8s//charts/gateway-web-public/templates/gateway-web-public-configmap.yaml ):
apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ .Release.Name }}-{{ .Chart.Name }}-configmap
data:
  yarp.json: |-
    {
      "ReverseProxy": {
        "Routes": {
          "AbpApi": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/abp/{**catch-all}"
            }
          },
          "AdministrationSwagger": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/swagger-json/Administration/swagger/v1/swagger.json"
            },
            "Transforms": [
              { "PathRemovePrefix": "/swagger-json/Administration" }
            ]
          },
          "Account": {
            "ClusterId": "AuthServer",
            "Match": {
              "Path": "/api/account/{**catch-all}"
            }
          },
          "AuthServerSwagger": {
            "ClusterId": "AuthServer",
            "Match": {
              "Path": "/swagger-json/AuthServer/swagger/v1/swagger.json"
            },
            "Transforms": [
              { "PathRemovePrefix": "/swagger-json/AuthServer" }
            ]
          },
          "Product": {
            "ClusterId": "Product",
            "Match": {
              "Path": "/api/product-service/{**catch-all}"
            }
          },
          "ProductSwagger": {
            "ClusterId": "Product",
            "Match": {
              "Path": "/swagger-json/Product/swagger/v1/swagger.json"
            },
            "Transforms": [
              { "PathRemovePrefix": "/swagger-json/Product" }
            ]
          }
        },
        "Clusters": {
          "AuthServer": {
            "Destinations": {
              "AuthServer": {
                "Address": "{{ .Values.reRoutes.accountService.url }}"
              }
            }
          },
          "Administration": {
            "Destinations": {
              "Administration": {
                "Address": "{{ .Values.reRoutes.administrationService.url }}"
              }
            }
          },
          "Product": {
            "Destinations": {
              "Product": {
                "Address": "{{ .Values.reRoutes.productService.url }}"
              }
            }
          }
        }
      }
    }
- Make the following changes in the gateway-web-public-deployment.yamlfile (etc/k8s//charts/gateway-web-public/templates/gateway-web-public-deployment.yaml ):
-          mountPath: /app/ocelot.json
+          mountPath: /app/yarp.json
-          subPath: ocelot.json
+          subPath: yarp.json
- Update the values.yamlfile as follows (etc/k8s//charts/gateway-web-public/values.yaml ):
config:
  selfUrl: # https://gateway-public.myprojectname.dev
  corsOrigins: # https://myprojectname-st-gateway-web,https://myprojectname-st-gateway-public-web
  authServer:
    authority: # http://myprojectname-st-authserver
    requireHttpsMetadata: # "false"
    metadataAddress: # https://authserver.myprojectname.dev/.well-known/openid-configuration
    swaggerClientId: # WebGateway_Swagger
  dotnetEnv: Staging 
  redisHost: #
  rabbitmqHost: #
  elasticsearchUrl: #
  AbpLicenseCode: #
reRoutes:
  accountService:
    url: http://myprojectname-st-authserver
  saasService:
    url: http://saas-st-administration
  administrationService:
    url: http://myprojectname-st-administration
  productService:
    url: http://myprojectname-st-product
ingress:
  host: gateway-public.myprojectname.dev
  tlsSecret: myprojectname-tls
image:
  repository: mycompanyname/myprojectname-gateway-web-public
  tag: latest
  pullPolicy: IfNotPresent
env: {}
- Update the gateway-web-configmap.yamlas follows (etc/k8s//charts/gateway-web/templates/gateway-web-configmap.yaml ):
apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ .Release.Name }}-{{ .Chart.Name }}-configmap
data:
  yarp.json: |-
    {
      "ReverseProxy": {
        "Routes": {
          "AbpApi": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/abp/{**catch-all}"
            }
          },
          "SettingManagement": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/setting-management/{**catch-all}"
            }
          },
          "FeatureManagement": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/feature-management/{**catch-all}"
            }
          },
          "PermissionManagement": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/permission-management/{**catch-all}"
            }
          },
          "AuditLogging": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/audit-logging/{**catch-all}"
            }
          },
          "LanguageManagement": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/language-management/{**catch-all}"
            }
          },
          "TextTemplateManagement": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/text-template-management/{**catch-all}"
            }
          },
          "LeptonThemeManagement": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/lepton-theme-management/{**catch-all}"
            }
          },
          "GDPR": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/api/gdpr/{**catch-all}"
            }
          },
          "AdministrationSwagger": {
            "ClusterId": "Administration",
            "Match": {
              "Path": "/swagger-json/Administration/swagger/v1/swagger.json"
            },
            "Transforms": [
              { "PathRemovePrefix": "/swagger-json/Administration" }
            ]
          },
          "Account": {
            "ClusterId": "AuthServer",
            "Match": {
              "Path": "/api/account/{**catch-all}"
            }
          },
          "AccountAdmin": {
            "ClusterId": "AuthServer",
            "Match": {
              "Path": "/api/account-admin/{**catch-all}"
            }
          },
          "AuthServerSwagger": {
            "ClusterId": "AuthServer",
            "Match": {
              "Path": "/swagger-json/AuthServer/swagger/v1/swagger.json"
            },
            "Transforms": [
              { "PathRemovePrefix": "/swagger-json/AuthServer" }
            ]
          },
          "Identity": {
            "ClusterId": "Identity",
            "Match": {
              "Path": "/api/identity/{**catch-all}"
            }
          },
          "OpenIddict": {
            "ClusterId": "Identity",
            "Match": {
              "Path": "/api/openiddict/{**catch-all}"
            }
          },
          "IdentitySwagger": {
            "ClusterId": "Identity",
            "Match": {
              "Path": "/swagger-json/Identity/swagger/v1/swagger.json"
            },
            "Transforms": [
              { "PathRemovePrefix": "/swagger-json/Identity" }
            ]
          },
          "Saas": {
            "ClusterId": "Saas",
            "Match": {
              "Path": "/api/saas/{**catch-all}"
            }
          },
          "Payment": {
            "ClusterId": "Saas",
            "Match": {
              "Path": "/api/payment/{**catch-all}"
            }
          },
          "PaymentAdmin": {
            "ClusterId": "Saas",
            "Match": {
              "Path": "/api/payment-admin/{**catch-all}"
            }
          },
          "SaasSwagger": {
            "ClusterId": "Saas",
            "Match": {
              "Path": "/swagger-json/Saas/swagger/v1/swagger.json"
            },
            "Transforms": [
              { "PathRemovePrefix": "/swagger-json/Saas" }
            ]
          },
          "Product": {
            "ClusterId": "Product",
            "Match": {
              "Path": "/api/product-service/{**catch-all}"
            }
          },
          "ProductSwagger": {
            "ClusterId": "Product",
            "Match": {
              "Path": "/swagger-json/Product/swagger/v1/swagger.json"
            },
            "Transforms": [
              { "PathRemovePrefix": "/swagger-json/Product" }
            ]
          }
        },
        "Clusters": {
          "AuthServer": {
            "Destinations": {
              "AuthServer": {
                "Address": "{{ .Values.reRoutes.accountService.url }}"
              }
            }
          },
          "Administration": {
            "Destinations": {
              "Administration": {
                "Address": "{{ .Values.reRoutes.administrationService.url }}"
              }
            }
          },
          "Identity": {
            "Destinations": {
              "Identity": {
                "Address": "{{ .Values.reRoutes.identityService.url }}"
              }
            }
          },
          "Saas": {
            "Destinations": {
              "Saas": {
                "Address": "{{ .Values.reRoutes.saasService.url }}"
              }
            }
          },
          "Product": {
            "Destinations": {
              "Product": {
                "Address": "{{ .Values.reRoutes.productService.url }}"
              }
            }
          }
        }
      }
    }
- Make the following changes in the gateway-web-deployment.yamlfile (etc/k8s//charts/gateway-web/templates/gateway-web-deployment.yaml ):
-          mountPath: /app/ocelot.json
+          mountPath: /app/yarp.json
-          subPath: ocelot.json
+          subPath: yarp.json
- Update the values.yamlfile as follows (etc/k8s//charts/gateway-web/values.yaml ):
config:
  selfUrl: # https://gateway-web.myprojectname.dev
  corsOrigins: # https://myprojectname-st-angular
  globalConfigurationBaseUrl: # http://myprojectname-st-gateway-web
  authServer:
    authority: # http://myprojectname-st-authserver
    requireHttpsMetadata: # "false"
    metadataAddress: # https://authserver.myprojectname.dev/.well-known/openid-configuration
    swaggerClientId: # WebGateway_Swagger
  dotnetEnv: # 
  redisHost: #
  rabbitmqHost: #
  elasticsearchUrl: #
  AbpLicenseCode: #
  
reRoutes:
  accountService:
    url: http://myprojectname-st-authserver
  saasService:
    url: http://saas-st-administration
  administrationService:
    url: http://myprojectname-st-administration
  identityService:
    url: http://myprojectname-st-identity
  productService:
    url: http://myprojectname-st-product
ingress:
  host: # gateway-web.myprojectname.dev
  tlsSecret: myprojectname-tls
image:
  repository: mycompanyname/myprojectname-gateway-web
  tag: latest
  pullPolicy: IfNotPresent
env: {}
- Update the values.yamlfile as follows (etc/k8s//values.yaml ):
- globalConfigurationBaseUrl: http://myprojectname-st-gateway-web
reRoutes:
    accountService:
+      url: http://myprojectname-st-authserver
-      dns: https://authserver.myprojectname.dev
-      schema: http
-      host: myprojectname-st-authserver
-      port: 80
    identityService:
+      url: http://myprojectname-st-identity
-      dns: https://identity.myprojectname.dev
-      schema: http
-      host: myprojectname-st-identity
-      port: 80
    administrationService:
+      url: http://myprojectname-st-administration
-      dns: https://administration.myprojectname.dev
-      schema: http
-      host: myprojectname-st-administration
-      port: 80
    saasService:
+      url: http://myprojectname-st-saas
-      dns: https://saas.myprojectname.dev
-      schema: http
-      host: myprojectname-st-saas
-      port: 80
    productService:
+      url: http://myprojectname-st-product
-      dns: https://product.myprojectname.dev
-      schema: http
-      host: myprojectname-st-product
-      port: 80  
 
                                             
                                    