6. 对象存储

6. 对象存储

什么是对象存储

在工作中,我们经常需要将文件内容(文件或二进制流)存储在应用程序中,例如你可能要保存商品的封面图片。Masa框架为此提供了对象存储的功能,并对功能抽象,抽象给我们带来的好处:

  • 存储的无关性(不关心存储平台时阿里云OSS还是腾讯云的COS)
  • 更换存储平台成本更低(仅需要更改下存储的提供者,业务侵染低)
  • 支持自定义存储提供者(仅需要自行实现IClient

对象存储提供程序

目前仅支持阿里云存储,后续将逐步提供更多的云存储平台支持,如果您有喜欢的其它云存储平台,欢迎提建议,或者自己实现它并为Masa框架做出贡献

如何制作自定义存储程序?

快速入门

Masa.BuildingBlocks.Storage.ObjectStorage是对象存储服务的抽象包,你可以在项目中使用它来进行编写代码,最后在Program.cs中选择一个存储提供程序使用即可

  1. 新建ASP.NET Core 空项目Assignment.OSS,并安装Masa.Contrib.Storage.ObjectStorage.Aliyun

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    dotnet new web -o Assignment.OSS
    cd Assignment.OSS
    dotnet add package Masa.Contrib.Storage.ObjectStorage.Aliyun --version 0.5.0-preview.2
  2. 修改Program.cs

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    builder.Services.AddAliyunStorage();

    #region 或者通过代码指定传入阿里云存储配置信息使用,无需使用配置文件
    // builder.Services.AddAliyunStorage(new AliyunStorageOptions()
    // {
    // AccessKeyId = "Replace-With-Your-AccessKeyId",
    // AccessKeySecret = "Replace-With-Your-AccessKeySecret",
    // Endpoint = "Replace-With-Your-Endpoint",
    // RoleArn = "Replace-With-Your-RoleArn",
    // RoleSessionName = "Replace-With-Your-RoleSessionName",
    // Sts = new AliyunStsOptions()
    // {
    // RegionId = "Replace-With-Your-Sts-RegionId",
    // DurationSeconds = 3600,
    // EarlyExpires = 10
    // }
    // }, "storage1-test");
    #endregion
  3. 修改appsettings.json,增加阿里云配置

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    {
    "Aliyun": {
    "AccessKeyId": "Replace-With-Your-AccessKeyId",
    "AccessKeySecret": "Replace-With-Your-AccessKeySecret",
    "Sts": {
    "RegionId": "Replace-With-Your-Sts-RegionId",
    "DurationSeconds": 3600,
    "EarlyExpires": 10
    },
    "Storage": {
    "Endpoint": "Replace-With-Your-Endpoint",
    "RoleArn": "Replace-With-Your-RoleArn",
    "RoleSessionName": "Replace-With-Your-RoleSessionName",
    "TemporaryCredentialsCacheKey": "Aliyun.Storage.TemporaryCredentials",
    "Policy": "",
    "BucketNames" : {
    "DefaultBucketName" : "storage1-test"//默认BucketName,非必填项,仅在使用IClientContainer时需要指定
    }
    }
    }
    }
  4. 新增上传文件服务

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    app.MapPost("/upload", async (HttpRequest request, IClient client) =>
    {
    var form = await request.ReadFormAsync();
    var formFile = form.Files["file"];
    if (formFile == null)
    throw new FileNotFoundException("Can't upload empty file");

    await client.PutObjectAsync("storage1-test", formFile.FileName, formFile.OpenReadStream());
    });

进阶

IClient

IClient是用来存储和读取对象的主要接口,可以在项目的任意地方通过DI获取到IClient来上传、下载或删除指定BucketName下的对象,也可用于判断对象是否存在,获取临时凭证等。

  1. 上传对象

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    app.MapPost("/upload", async (HttpRequest request, IClient client) =>
    {
    var form = await request.ReadFormAsync();
    var formFile = form.Files["file"];
    if (formFile == null)
    throw new FileNotFoundException("Can't upload empty file");

    await client.PutObjectAsync("storage1-test", formFile.FileName, formFile.OpenReadStream());
    });

    Form表单提交,key为file,类型为文件上传

  2. 删除对象

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    public class DeleteRequest
    {
    public string Key { get; set; }
    }

    app.MapDelete("/delete", async (IClient client, [FromBody] DeleteRequest request) =>
    {
    await client.DeleteObjectAsync("storage1-test", request.Key);
    });
  3. 判断对象是否存在

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    app.MapGet("/exist", async (IClient client, string key) =>
    {
    await client.ObjectExistsAsync("storage1-test", key);
    });
  4. 返回对象数据的流

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    app.MapGet("/download", async (IClient client, string key, string path) =>
    {
    await client.GetObjectAsync("storage1-test", key, stream =>
    {
    //下载文件到指定路径
    using var requestStream = stream;
    byte[] buf = new byte[1024];
    var fs = File.Open(path, FileMode.OpenOrCreate);
    int len;
    while ((len = requestStream.Read(buf, 0, 1024)) != 0)
    {
    fs.Write(buf, 0, len);
    }
    fs.Close();
    });
    });
  5. 获取临时凭证(STS)

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    app.MapGet("/GetSts", (IClient client) =>
    {
    client.GetSecurityToken();
    });

    阿里云腾讯云存储等平台使用STS来获取临时凭证

  6. 获取临时凭证(字符串类型的临时凭证)

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    app.MapGet("/GetToken", (IClient client) =>
    {
    client.GetToken();
    });

    七牛云等存储平台使用较多

IBucketNameProvider

IBucketNameProvider是用来获取BucketName的接口,通过IBucketNameProvider可以获取指定存储空间的BucketName,为IClientContainer提供BucketName能力,在业务项目中不会使用到

IClientContainer

IClientContainer对象存储容器,用来存储和读取对象的主要接口,一个应用程序下可能会存在管理多个BucketName,通过使用IClientContainer,像管理DbContext一样管理不同Bucket的对象,不需要在项目中频繁指定BucketName,在同一个应用程序中,有且只有一个默认ClientContainer,可以通过DI获取IClientContainer来使用,例如:

  • 上传对象(上传到默认Bucket

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    app.MapPost("/upload", async (HttpRequest request, IClientContainer clientContainer) =>
    {
    var form = await request.ReadFormAsync();
    var formFile = form.Files["file"];
    if (formFile == null)
    throw new FileNotFoundException("Can't upload empty file");

    await clientContainer.PutObjectAsync(formFile.FileName, formFile.OpenReadStream());
    });
  • 上传到指定Bucket

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    [BucketName("picture")]
    public class PictureContainer
    {

    }

    builder.Services.Configure<StorageOptions>(option =>
    {
    option.BucketNames = new BucketNames(new List<KeyValuePair<string, string>>()
    {
    new("DefaultBucketName", "storage1-test"),//默认BucketName
    new("picture", "storage1-picture")//指定别名为picture的BucketName为storage1-picture
    });
    });

    app.MapPost("/upload", async (HttpRequest request, IClientContainer<PictureContainer> clientContainer) =>
    {
    var form = await request.ReadFormAsync();
    var formFile = form.Files["file"];
    if (formFile == null)
    throw new FileNotFoundException("Can't upload empty file");

    await clientContainer.PutObjectAsync(formFile.FileName, formFile.OpenReadStream());
    });

IClientFactory

IClientFactory对象存储提供者工厂,通过指定BucketName,创建指定的IClientContainer

创建对象存储提供程序

以适配腾讯云存储为例:

  1. 新建类库Masa.Contrib.Storage.ObjectStorage.Tencent

  2. 选中Masa.Contrib.Storage.ObjectStorage.Tencent并新建类DefaultStorageClient,并实现IClient

  3. 由于腾讯云存储提供Sts临时凭证,所以仅需要实现GetSecurityToken方法即可,GetToken方法可抛出不支持的异常,并在文档说明即可

  4. 新建类ServiceCollectionExtensions,并提供对IServiceCollection的扩展方法AddTencentStorage,例如:

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    public static IServiceCollection AddTencentStorage(
    this IServiceCollection services,
    TencentStorageOptions options,
    string? defaultBucketName = null)
    {
    //todo: 添加腾讯云存储的客户端
    if (defaultBucketName != null)
    {
    services.Configure<StorageOptions>(option =>
    {
    option.BucketNames = new BucketNames(new List<KeyValuePair<string, string>>()
    {
    new(BucketNames.DEFAULT_BUCKET_NAME, defaultBucketName)
    });
    });
    services.TryAddSingleton<IClientContainer>(serviceProvider
    => new DefaultClientContainer(serviceProvider.GetRequiredService<IClient>(), defaultBucketName));
    }
    services.TryAddSingleton<IClientFactory, DefaultClientFactory>();
    services.TryAddSingleton<ICredentialProvider, DefaultCredentialProvider>();
    services.TryAddSingleton<IClient, DefaultStorageClient>();
    return services;
    }

总结

目前对象存储暂时并未支持多租户、多环境,后续根据情况逐步完善增加多租户、多环境支持,以适配不同的租户、不同的环境下的对象存储到指定的Bucket

本章源码

Assignment06

https://github.com/zhenlei520/MasaFramework.Practice

开源地址

MASA.BuildingBlocks:https://github.com/masastack/MASA.BuildingBlocks

MASA.Contrib:https://github.com/masastack/MASA.Contrib

MASA.Utils:https://github.com/masastack/MASA.Utils

MASA.EShop:https://github.com/masalabs/MASA.EShop

MASA.Blazor:https://github.com/BlazorComponent/MASA.Blazor

如果你对我们的 MASA Framework 感兴趣,无论是代码贡献、使用、提 Issue,欢迎联系我们

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作者

MASA

发布于

2022-06-01

更新于

2022-09-26

许可协议