[C#/ASP.NET MVC/.NETCORE] PollyHttpClientBuilderExtensions 클래스 : AddPolicyHandler 확장 메소드를 사용해 동적으로 정책 선택하기

■ PollyHttpClientBuilderExtensions 클래스의 AddPolicyHandler 확장 메소드를 사용해 동적으로 정책을 선택하는 방법을 보여준다.

▶ Startup.cs


using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using System;
using System.Net.Http;

using Polly;
using Polly.Timeout;

namespace TestProject
{
    /// <summary>
    /// 시작
    /// </summary>
    public class Startup
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Property
        ////////////////////////////////////////////////////////////////////////////////////////// Public

        #region 구성 - Configuration

        /// <summary>
        /// 구성
        /// </summary>
        public IConfiguration Configuration { get; }

        #endregion

        //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor
        ////////////////////////////////////////////////////////////////////////////////////////// Public

        #region 생성자 - Startup(configuration)

        /// <summary>
        /// 생성자
        /// </summary>
        /// <param name="configuration">구성</param>
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        #endregion

        //////////////////////////////////////////////////////////////////////////////////////////////////// Method
        ////////////////////////////////////////////////////////////////////////////////////////// Public

        #region 서비스 컬렉션 구성하기 - ConfigureServices(services)

        /// <summary>
        /// 서비스 컬렉션 구성하기
        /// </summary>
        /// <param name="services">서비스 컬렉션</param>
        public void ConfigureServices(IServiceCollection services)
        {
            AsyncTimeoutPolicy<HttpResponseMessage> regularTimeoutPolicy = Policy.TimeoutAsync<HttpResponseMessage>
            (
                TimeSpan.FromSeconds(10)
            );

            AsyncTimeoutPolicy<HttpResponseMessage> longTimeoutPolicy = Policy.TimeoutAsync<HttpResponseMessage>
            (
                TimeSpan.FromSeconds(30)
            );

            services.AddHttpClient("test")
                .AddPolicyHandler
                (
                    request => request.Method == HttpMethod.Get ? regularTimeoutPolicy : longTimeoutPolicy
                );

            services.AddControllers();

            services.AddRazorPages();
        }

        #endregion
        #region 구성하기 - Configure(app, environment)

        /// <summary>
        /// 구성하기
        /// </summary>
        /// <param name="app">애플리케이션 빌더</param>
        /// <param name="environment">웹 호스트 환경</param>
        public void Configure(IApplicationBuilder app, IWebHostEnvironment environment)
        {
            if(environment.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Error");
            }

            app.UseRouting();

            app.UseEndpoints
            (
                endpoints =>
                {
                    endpoints.MapControllerRoute
                    (
                        name    : "default",
                        pattern : "{controller=Home}/{action=Index}/{id?}"
                    );

                    endpoints.MapRazorPages();
                }
            );
        }

        #endregion
    }
}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

using Microsoft.AspNetCore.Builder;

using Microsoft.AspNetCore.Hosting;

using Microsoft.Extensions.Configuration;

using Microsoft.Extensions.DependencyInjection;

using Microsoft.Extensions.Hosting;

using System;

using System.Net.Http;

using Polly;

using Polly.Timeout;

namespace TestProject

{

/// <summary>

/// 시작

/// </summary>

public class Startup

{

//////////////////////////////////////////////////////////////////////////////////////////////////// Property

////////////////////////////////////////////////////////////////////////////////////////// Public

#region 구성 - Configuration

/// <summary>

/// 구성

/// </summary>

public IConfiguration Configuration { get; }

#endregion

//////////////////////////////////////////////////////////////////////////////////////////////////// Constructor

////////////////////////////////////////////////////////////////////////////////////////// Public

#region 생성자 - Startup(configuration)

/// <summary>

/// 생성자

/// </summary>

/// <param name="configuration">구성</param>

public Startup(IConfiguration configuration)

{

Configuration = configuration;

}

#endregion

//////////////////////////////////////////////////////////////////////////////////////////////////// Method

////////////////////////////////////////////////////////////////////////////////////////// Public

#region 서비스 컬렉션 구성하기 - ConfigureServices(services)

/// <summary>

/// 서비스 컬렉션 구성하기

/// </summary>

/// <param name="services">서비스 컬렉션</param>

public void ConfigureServices(IServiceCollection services)

{

AsyncTimeoutPolicy<HttpResponseMessage> regularTimeoutPolicy = Policy.TimeoutAsync<HttpResponseMessage>

(

TimeSpan.FromSeconds(10)

);

AsyncTimeoutPolicy<HttpResponseMessage> longTimeoutPolicy = Policy.TimeoutAsync<HttpResponseMessage>

(

TimeSpan.FromSeconds(30)

);

services.AddHttpClient("test")

.AddPolicyHandler

(

request => request.Method == HttpMethod.Get ? regularTimeoutPolicy : longTimeoutPolicy

);

services.AddControllers();

services.AddRazorPages();

}

#endregion

#region 구성하기 - Configure(app, environment)

/// <summary>

/// 구성하기

/// </summary>

/// <param name="app">애플리케이션 빌더</param>

/// <param name="environment">웹 호스트 환경</param>

public void Configure(IApplicationBuilder app, IWebHostEnvironment environment)

{

if(environment.IsDevelopment())

{

app.UseDeveloperExceptionPage();

}

else

{

app.UseExceptionHandler("/Error");

}

app.UseRouting();

app.UseEndpoints

(

endpoints =>

{

endpoints.MapControllerRoute

(

name : "default",

pattern : "{controller=Home}/{action=Index}/{id?}"

);

endpoints.MapRazorPages();

}

);

}

#endregion

}

※ 설치 패키지 : Microsoft.Extensions.Http.Polly