update dmi docs

docs/developer/dmi.md

@@ -0,0 +1,40 @@
+---
+title: Device Management Interface
+sidebar_position: 1
+---
+
+## DMI
+Device Management Interface(DMI) integrates the device management interface and optimizes the device management capability of KubeEdge. 
+It is the goal of KubeEdge DMI that builds a cloud native device twin management platform which covers device management, device operation and device data management.
+DMI defines a unified connection entrance between EdgeCore and Mapper, and EdgeCore and Mapper implement the upstream data flow and downstream data flow respectively,
+At the same time, DMI decouples device management plane and device data plane , allowing device management plane to only carry the life cycle 
+management of the device itself, while device data plane is directly provided to data consumer applications through microservices.
+Under such an architecture, device data is pushed directly from the data plane and does not necessarily need to be pushed to the cloud. 
+This allows the cloud-edge channel to transmit only a small amount of management plane information, reducing the possibility of cloud-edge communication congestion.
+
+
+### Architecture
+![DMI](/img/device/DMI.png)
+
+### Device management and data management in DMI
+The picture above is the design diagram of DMI device management and data management. The yellow line is the 
+device management process and the blue line is the data management process.
+
+In the architectural design of DMI, the device management plane mainly includes the device's metadata, 
+device attributes, configuration, status, life cycle, etc. It is characterized by being relatively stable. 
+After creation, there are fewer updates of information except status reporting, and it is closer to the Pod. 
+Users can maintain the life cycle of Device through the cloud Kubernetes API just like accessing Pod, while minimizing the additional data transmission overhead caused by 
+device management.
+
+In DMI design, the device provides data services to device data consumers in a cloud-native manner. Device data access under 
+the DMI framework supports multiple scenarios and is more flexible. The above figure lists several main data access 
+methods, including push data and pull data, etc. The details are as follows:
+1. Mapper pushes data to cloud/edge applications by configuring the destination address.
+2. Mapper pushes data to cloud/edge databases by configuring the destination address.
+3. Users applications actively pull device data through the API.
+4. Mapper pushes device data to the cloud through the cloud edge channel
+
+### DMI interface definition
+DMI interface definition refers to [DMI interface](https://github.com/kubeedge/kubeedge/blob/master/pkg/apis/dmi/services.go)
+The current version of DMI interface is defined in gRPC proto.  
+You can use the generate-dmi-proto [script](https://github.com/kubeedge/kubeedge/blob/master/hack/generate-dmi-proto.sh) to create the corresponding gRPC-go code.

i18n/zh/docusaurus-plugin-content-docs/current/developer/dmi.md

@@ -0,0 +1,34 @@
+---
+title: 设备管理框架
+sidebar_position: 1
+---
+
+## 设备管理框架
+
+设备管理框架（Device Management Interface，DMI）集成了设备管理接口，优化了KubeEdge的设备管理能力。KubeEdge DMI的目标是
+构建一个涵盖设备管理、设备操作和设备数据处理的云原生设备孪生管理平台。 DMI定义了EdgeCore和Mapper之间的统一连接入口，
+EdgeCore和Mapper分别实现上游数据流和下游数据流，同时，DMI解耦了设备管理面和设备数据面，让设备管理面只承载设备生命周期的管理，
+而设备数据面通过微服务直接提供给数据消费应用程序。在这样的架构下，设备数据直接从数据面推送，不一定需要推送到云端。这使得云边通道能够
+只传输少量的管理面信息，减少了云边通信拥塞的可能性。
+
+### 架构
+![DMI](/img/device/DMI.png)
+
+### DMI中的设备管理和数据管理
+上图是DMI设备管理和数据管理的设计图。黄线是设备管理流程，蓝线是数据管理流程。
+
+在DMI的架构设计中，设备管理面主要包括设备的元数据、设备属性、配置、状态、生命周期等。其特点是比较稳定。创建后，除了状态报告之外，
+信息的更新较少，接近于Pod。 用户可以像访问Pod一样通过云端Kubernetes API维护Device的生命周期，同时最大限度地减少设备管理带来的
+额外数据传输开销。
+
+在DMI设计中，设备以云原生的方式向设备数据消费者提供数据服务。DMI框架下的设备数据访问支持多种场景，更加灵活。上图列出了几个主要的数据访问
+方法，包括推送数据和拉取数据等，具体如下：
+
+1. Mapper通过配置目标地址将数据推送到云/边缘应用程序。
+2. Mapper通过配置目标地址将数据推送到云/边缘数据库。
+3. 用户应用程序通过 API 主动拉取设备数据。
+4. Mapper通过云边通道将设备数据推送到云端。
+
+### DMI接口定义
+DMI接口定义可以参考 [DMI interface](https://github.com/kubeedge/kubeedge/blob/master/pkg/apis/dmi/services.go)。
+当前版本的 DMI 接口是在 gRPC proto 中定义的。你可以使用generate-dmi-proto脚本创建相应的gRPC-go代码。