网关never_host设计

//统一使用配置中心，方便管理
e.startup.useconfigclient(new ipendpoint(ipaddress.parse(configreader["config_host"]), configreader.intinappconfig("config_port")), out var configfileclient);
//启动配置中心，每10秒的心跳，并且指定当前读取配置中心下面的app_host文件内容。
configfileclient.startup(timespan.fromminutes(10), new[] { new configfileclientrequest { filename = "app_host" } }, (c, t) =>
{
    var content = t;
    if (c != null && c.filename == "app_host")
    {
        system.io.file.writealltext(system.io.path.combine(this.environment.contentrootpath, "appsettings.app.json"), content);
    }
}).push("app_host").getawaiter().getresult();

//程序名字
var pathtoexe = system.diagnostics.process.getcurrentprocess().mainmodule.filename;
//程序所在位置
var pathtocontentroot = path.getdirectoryname(pathtoexe);
return webhost.createdefaultbuilder(args)
//监听2个文件
    .usejsonfileconfig(never.web.webapi.startupextension.configfilebuilder(new[] { "appsettings.json", "appsettings.app.json" }))
//使用kestrel
    .usekestrel((builder, option) =>
    {
        //主要是重写监听url
        var ports = string.empty;option.listen(system.net.ipaddress.any, ports);

}) .usecontentroot(pathtocontentroot) .usestartup<startup>()

//config builder
builder.configureappconfiguration((h, g) =>
{
    var files = jsonconfigfiles?.invoke(h);
    if (files.isnotnullorempty())
    {
        foreach (var file in files)
        {
            if (file.exists)
                g.addconfiguration(new configurationbuilder().setbasepath(h.hostingenvironment.contentrootpath).addjsonfile(file.fullname, true, true).build());
            else
                throw new system.io.filenotfoundexception(string.format("找不到文件{0}", file.fullname));
        }
    }
});

//读取服务地址，构造函数可以传递如何匹配a10url内容的回调
private class proxyroutedispatcher : defaultapirouteprovider
{
    private readonly iconfigreader configreader = null;

    public proxyroutedispatcher(iconfigreader configreader)
    {
        this.configreader = configreader;
    }

    public override ienumerable<apiurla10element> apiurla10elements
    {
        get
        {
            /*读取appa10:url:0，appa10:url:.1这个配置信息，如下面的配置
                * {
                    "application": "true",
                    "version": "1123",
                    "appa10": {
                    "url": [ "http://127.0.0.1:8081/", "http://127.0.0.1:8081/" ],
                    "ping": [ "http://127.0.0.1:8081/a10", "http://127.0.0.1:8081/a10" ]
                    }
                }
                */
        }
    }
}

/// <summary>
/// 路由中间件
/// </summary>
private class proxymiddlewear : imiddleware
{
    private readonly authenticationservice authenticationservice = null;
    private readonly iapiuridispatcher proxyroutedispatcher = null;

    public proxymiddlewear(authenticationservice authenticationservice, iconfigreader configreader)
    {
        this.authenticationservice = authenticationservice;
        var provider = new proxyroutedispatcher(configreader);
        //开户一个健康检查，表示60秒会检查一遍，检查地址为proxyroutedispatcher.apiurla10elements里面的a10url
        var a10 = never.deployment.startupextension.startreport().startup(60, new[] { provider });
        this.proxyroutedispatcher = new apiuridispatcher<iapirouteprovider>(provider, a10);
    }
}

//拿api地址，如果存在多条可用的api地址的话，则找出其中一条，这里还要结合限流等策略
var host = new hoststring(this.proxyroutedispatcher.getcurrenturlhost((context.request.contentlength.hasvalue ? context.request.contentlength.value : segments[1].gethashcode()).tostring()));
var url = urihelper.buildabsolute("http", host, context.request.pathbase, context.request.path, context.request.querystring, default(fragmentstring));

//客户端地址
if (context.connection.remoteipaddress != null)
{
    headers["ip"] = context.connection.remoteipaddress.tostring();
}
if (context.request.headers != null)
{
    //通过x-real-ip，x-forwarded-for等nginx传递过来的客户端ip地址
    headers["ip"] = context.getcontextip();
}

//查询身份认证，accesstoken不要传递到api，api根本不知道这个accesstoken是用来做什么的
var user = this.authenticationservice.getuser(context, token);
if (user.hasvalue && user.value > 0)
{
    headers["userid"] = user.value.tostring();
}
//查找platform关键信息
if (context.request.headers != null && context.request.headers.keys.any(ta=>ta.isequals("platform")))
{
    var value = context.request.headers["platform"];
    headers["platform"] = value.tostring();
}

//开始请求
using (var body = this.convertcontentfrombodybytearray(context, enctryptor))
{
    using (var method = new never.utils.methodtickcount(""))
    {
        var task = new httprequestdownloader().poststring(new uri(url), body, header, "application/json");
        var content = task;// task.getawaiter().getresult();
        return this.convertcontenttobody(context, content, enctryptor);
    }
}

//请求的body读取后进行3des解密
private stream convertcontentfrombodybytearray(httpcontext context, icontentencryptor enctryptor)
{
    using (var st = new memorystream())
    {
        context.request.body.copyto(st);
        st.position = 0;
        var @byte = st.toarray();
        return enctryptor.decrypt(@byte, new[] { "utf-8" });
    }
}

//请求回来的内容将进行3desc加密
private task convertcontenttobody(httpcontext context, byte[] content, icontentencryptor enctryptor)
{
    var @byte = enctryptor.encrypt(content);
    return context.response.body.writeasync(@byte, 0, @byte.length);
}

//请求回来的内容将进行3desc加密
private task convertcontenttobody(httpcontext context, string content, icontentencryptor enctryptor)
{
    var @string = enctryptor.encrypt(content);
    return context.response.writeasync(@string);
}

/// <summary>
/// 获取从header中token
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public token gettoken(httpcontext context)
{
    //查询accesstoken
    var token = context.request.headers.containskey("accesstoken") ? context.request.headers["accesstoken"].firstordefault() : string.empty;
    //空的话返回默认的token
    if (string.isnullorempty(token))
    {
        return new token() { crypttoken = "56dc54a07f3d15a400000155" };
    }
    //尝试对accesstoken使用加解密
    try
    {
        var splits = token.from3des("56dc54a07f3d15a400000155").split('|');
        if (splits != null && splits.length == 2)
        {
            return new token()
            {
                accesstoken = token,
                crypttoken = splits[0],
                usertoken = splits[1]
            };
        }
    }
    catch
    {
        //异常的话返回默认的token
        return new token() { crypttoken = "56dc54a07f3d15a400000155" };
    }
    //空的话返回默认的token
    return new token() { crypttoken = "56dc54a07f3d15a400000155" };
}

//host与api约定处理方案生成的accesstoken
using (var body = this.convertcontentfrombodybytearray(context, enctryptor))
{
    //注册与登陆，由于在这里做identity servie
    switch (segments[2])
    {
        //注册
        case "register":
        //登陆
        case "login":
            {
                var logintask = new httprequestdownloader().poststring(new uri(url), body, header, "application/json", 0);
                var logincontent = logintask;
                var target = easyjsonserializer.deserialize<never.web.webapi.controllers.basiccontroller.responseresult<useridtoken>>(logincontent);
                //验证成功，此时要生成accesstoken信息
                if (target != null && target.code == "0000" && target.data.userid > 0)
                {
                    var token2 = this.authenticationservice.signin(context, target.data.userid).getawaiter().getresult();
                    var appresult = new never.web.webapi.controllers.basiccontroller.responseresult<apptoken>(target.code, new apptoken { @accesstoken = token2.accesstoken }, target.message);
                    return this.convertcontenttobody(context, easyjsonserializer.serialize(appresult), enctryptor);
                }
                //验证不成功，返回验证信息
                var appresult2 = new never.web.webapi.controllers.basiccontroller.responseresult<apptoken>(target.code, new apptoken { @accesstoken = string.empty }, target.message);
                return this.convertcontenttobody(context, easyjsonserializer.serialize(appresult2), enctryptor);
            }
    }
}