doc: doc for casdoor (#47)

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@@ -7,9 +7,7 @@
     to you under the Apache License, Version 2.0 (the
     "License"); you may not use this file except in compliance
     with the License.  You may obtain a copy of the License at
-
         http://www.apache.org/licenses/LICENSE-2.0
-
     Unless required by applicable law or agreed to in writing,
     software distributed under the License is distributed on an
     "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
@@ -37,7 +35,9 @@
 
 [前端服务运行说明](frontend/README.md)
 
+## Casdoor运行
 
+[Casdoor单点登录运行说明](casdoor.md)
 
 
 ## Docker
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     to you under the Apache License, Version 2.0 (the
     "License"); you may not use this file except in compliance
     with the License.  You may obtain a copy of the License at
-
         http://www.apache.org/licenses/LICENSE-2.0
-
     Unless required by applicable law or agreed to in writing,
     software distributed under the License is distributed on an
     "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
@@ -36,4 +34,6 @@
 
 [前端服务运行说明](frontend/README.md)
 
+## Casdoor运行
 
+[Casdoor单点登录运行说明](casdoor.md)
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+<!--
+
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you under the Apache License, Version 2.0 (the
+    "License"); you may not use this file except in compliance
+    with the License.  You may obtain a copy of the License at
+        http://www.apache.org/licenses/LICENSE-2.0
+    Unless required by applicable law or agreed to in writing,
+    software distributed under the License is distributed on an
+    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+    KIND, either express or implied.  See the License for the
+    specific language governing permissions and limitations
+    under the License.
+
+-->
+
+[![License](https://img.shields.io/badge/license-Apache%202-4EB1BA.svg)](https://www.apache.org/licenses/LICENSE-2.0.html)
+![](https://img.shields.io/badge/java--language-1.8-blue.svg)
+
+# Casdoor
+
+Casdoor can simply connect to [Apache IoTDB](https://github.com/apache/iotdb).
+
+Because the code for connecting casdoor has been added in [Apache IoTDB Web Workbench](https://github.com/apache/iotdb-web-workbench), we just need to configure application.yml in back-end and open front switch.
+
+## Step1. Deploy Casdoor
+
+Firstly, the Casdoor should be deployed.
+
+You can refer to the Casdoor official documentation for the [Server Installation](/docs/basic/server-installation).
+
+After a successful deployment, you need to ensure:
+
+- The Casdoor server is successfully running on **http://localhost:8000**.
+- Open your favorite browser and visit **http://localhost:7001**, you will see the login page of Casdoor.
+- Input `admin` and `123` to test login functionality is working fine.
+
+Then you can quickly implement a Casdoor-based login page in your own app with the following steps.
+
+## Step2. Configure Casdoor
+
+Configure casdoor can refer to [casdoor](https://door.casdoor.com/login)(Configure casdoor's browser better not use one browser as your develop browser).
+
+You also should configure an organization and an application. You also can refer to [casdoor](https://door.casdoor.com/login).
+
+### 2.1 you should create an organization
+
+![organization](/backend/doc/image/editOrganization.png)
+
+### 2.2 you should create an application
+
+![application](/backend/doc/image/editApplication.png)
+
+## Step3. Open Apache IoTDB Web Workbench front-end switch
+
+Open this switch to make code and state send to back-end.
+
+This switch in the iotdb-web-workbench/fronted/.env
+
+![frontSwitch](/backend/doc/image/frontSwitch.png)
+
+## Step4. Configure back-end code
+
+You should configure casdoor's Configuration in the iotdb-web-workbench/backend/src/main/resources/application.properties
+
+```ini
+casdoor.endpoint = http://localhost:8000
+casdoor.clientId = <client id in previous step>
+casdoor.clientSecret = <client Secret in previous step>
+casdoor.certificate=<client certificate in previous step>
+casdoor.organizationName=IoTDB
+casdoor.applicationName=app-IoTDB
+```
+
+## Result
+
+![result](/backend/doc/image/iotdb.gif)
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