.net - 使用Azure Service Fabric的默认客户端时如何向请求添加消息头？

Question

我想知道是否可以将自定义消息头注入(inject)到传出请求中以携带附加信息，而无需反序列化有效负载来完成身份验证、验证或请求关联等功能，例如通过消息检查器提供的 wcf ？

Answer 1

更新

使用 SDK v2，您现在可以(相对)轻松地修改 Reliable Services 和 Actor 的 header 。请注意，为了简洁起见，在下面的示例中省略了一些包装器成员。

客户端

我们使用ServiceProxyFactory来创建代理而不是静态ServiceProxy。然后我们可以包装 IServiceRemotingClientFactory 和 IServiceRemotingClient 并拦截服务调用。使用 ActorProxyFactory 也可以完成同样的操作。请注意，这会覆盖 WcfServiceRemotingProviderAttribute 等属性的行为，因为我们自己显式指定客户端工厂。

_proxyFactory = new ServiceProxyFactory(c => new ServiceRemotingClientFactoryWrapper(
 // we can use any factory here
 new WcfServiceRemotingClientFactory(callbackClient: c)));

    private class ServiceRemotingClientFactoryWrapper : IServiceRemotingClientFactory
    {
        private readonly IServiceRemotingClientFactory _inner;

        public ServiceRemotingClientFactoryWrapper(IServiceRemotingClientFactory inner)
        {
            _inner = inner;
        }

        public async Task<IServiceRemotingClient> GetClientAsync(Uri serviceUri, ServicePartitionKey partitionKey, TargetReplicaSelector targetReplicaSelector,
            string listenerName, OperationRetrySettings retrySettings, CancellationToken cancellationToken)
        {
            var client = await _inner.GetClientAsync(serviceUri, partitionKey, targetReplicaSelector, listenerName, retrySettings, cancellationToken).ConfigureAwait(false);
            return new ServiceRemotingClientWrapper(client);
        }
    }

    private class ServiceRemotingClientWrapper : IServiceRemotingClient
    {
        private readonly IServiceRemotingClient _inner;

        public ServiceRemotingClientWrapper(IServiceRemotingClient inner)
        {
            _inner = inner;
        }

        public Task<byte[]> RequestResponseAsync(ServiceRemotingMessageHeaders messageHeaders, byte[] requestBody)
        {
            // use messageHeaders.AddHeader() here
            return _inner.RequestResponseAsync(messageHeaders, requestBody);
        }

        public void SendOneWay(ServiceRemotingMessageHeaders messageHeaders, byte[] requestBody)
        {
            // use messageHeaders.AddHeader() here
            _inner.SendOneWay(messageHeaders, requestBody);
        }
    }

服务器

继承 ServiceRemotingDispatcher 和 ActorServiceRemotingDispatcher 以检查 header 。

class CustomServiceRemotingDispatcher : ServiceRemotingDispatcher
{
    public override async Task<byte[]> RequestResponseAsync(IServiceRemotingRequestContext requestContext, ServiceRemotingMessageHeaders messageHeaders, byte[] requestBody)
    {
        // read messageHeaders here
        // or alternatively put them in an AsyncLocal<T> scope
        // so they can be accessed down the call chain
        return base.RequestResponseAsync(requestContext, messageHeaders, requestBody);
    }
}

要使用此类，我们再次需要通过直接创建通信监听器来重写 ServiceRemotingProviderAttribute:

class MyService : StatelessService
{
     protected override IEnumerable<ServiceInstanceListener> CreateServiceInstanceListeners()
     {
          yield return new ServiceInstanceListener(context => new WcfServiceRemotingListener(context, new CustomServiceRemotingDispatcher());
     }
}