Add microservices-based composing guide

Signed-off-by: Sherlock113 <sherlockxu@yunify.com>

content/en/docs/project-user-guide/application/compose-app.md

@@ -1,10 +1,114 @@
 ---
-title: "Compose a Microservice App"
-keywords: 'kubesphere, kubernetes, docker, devops, service mesh, openpitrix'
-description: 'Compose a microservice-based application'
-
-
+title: "Create a Microservices-based App"
+keywords: 'KubeSphere, Kubernetes, service mesh, microservices'
+description: 'Create a microservices-based app'
+linkTitle: "Create a Microservices-based App"
 weight: 10140
 ---
 
-TBD
+With each microservice handling a single part of the app's functionality, an app can be divided into different components. These components have their own responsibilities and limitations, independent from each other. In KubeSphere, this kind of app is called **Composing App**, which can be built through newly created Services or existing Services.
+
+This tutorial demonstrates how to create a microservices-based app Bookinfo, which is composed of four Services, and set a customized domain name to access the app.
+
+## Prerequisites
+
+- You need to create a workspace, a project, and a user account (`project-regular`) for this tutorial. The account needs to be invited to the project with the `operator` role. For more information, see [Create Workspaces, Projects, Accounts and Roles](../../../quick-start/create-workspace-and-project/).
+- `project-admin` needs to [set the project gateway](../../../project-administration/project-gateway/) so that `project-regular` can define a domain name when creating the app.
+
+## Create Microservices that Compose an App
+
+1. Log in to the web console of KubeSphere and navigate to **Applications** in **Application Workloads** of your project. In the **Composing App** tab, click **Create Composing Application**.
+
+   ![create-composing-app](/images/docs/project-user-guide/applications/create-a-microservices-based-app/create-composing-app.png)
+
+2. Set a name for the app (e.g. `bookinfo`) and click **Next**.
+
+3. On the **Components** page, you need to create microservices that compose the app. Click **Add Service** and select **Stateless Service**.
+
+4. Set a name for the Service (e.g `productpage`) and click **Next**.
+
+   ![product-page](/images/docs/project-user-guide/applications/create-a-microservices-based-app/product-page.png)
+
+   {{< notice note >}}
+
+   You can create a Service on the dashboard directly or enable **Edit Mode** in the top right corner to edit the YAML file.
+
+   {{</ notice >}} 
+
+5. Click **Add Container Image** under **Container Image** and input `kubesphere/examples-bookinfo-productpage-v1:1.13.0` in the search bar to use the Docker Hub image.
+
+   ![container-image](/images/docs/project-user-guide/applications/create-a-microservices-based-app/container-image.png)
+
+   {{< notice note >}}
+
+   You must press **Enter** in your keyboard after you input the image name.
+
+   {{</ notice >}} 
+
+6. Click **Use Default Ports**. For more information about image settings, see [Container Image Settings](../../../project-user-guide/application-workloads/container-image-settings/). Click **√** in the bottom right corner and **Next** to continue.
+
+7. On the **Mount Volumes** page, [add a volume](../../../project-user-guide/storage/volumes/) or click **Next** to continue.
+
+8. Click **Add** on the **Advanced Settings** page directly.
+
+9. Similarly, add the other three microservices for the app. Here is the image information:
+
+   | Service   | Name      | Image                                            |
+   | --------- | --------- | ------------------------------------------------ |
+   | Stateless | `details` | `kubesphere/examples-bookinfo-details-v1:1.13.0` |
+   | Stateless | `reviews` | `kubesphere/examples-bookinfo-reviews-v1:1.13.0` |
+   | Stateless | `ratings` | `kubesphere/examples-bookinfo-ratings-v1:1.13.0` |
+
+10. When you finish adding microservices, click **Next**.
+
+    ![microservices-done](/images/docs/project-user-guide/applications/create-a-microservices-based-app/microservices-done.png)
+
+11. On the **Internet Access** page, click **Add Route Rule**. In the **Specify Domain** tab, set a domain name for your app (e.g. `demo.bookinfo`) and select `http` in the **Protocol** field. For `Paths`, select the Service `productpage` and port `9080`. Click **OK** to continue.
+
+    ![route](/images/docs/project-user-guide/applications/create-a-microservices-based-app/route.png)
+
+    {{< notice note >}}
+
+The button **Add Route Rule** is not visible if the project gateway is not set.
+
+{{</ notice >}} 
+
+12. You can add more rules or click **Create** to finish the process.
+
+13. Wait for your app to reach the **Ready** status.
+
+    ![status-active](/images/docs/project-user-guide/applications/create-a-microservices-based-app/status-active.png)
+
+## Access the App
+
+1. As you set a domain name for the app, you need to add an entry in the hosts (`/etc/hosts`) file. For example, add the IP address and hostname as below:
+
+   ```txt
+   192.168.0.9 demo.bookinfo
+   ```
+
+   {{< notice note >}}
+
+   You must add your **own** IP address and hostname.
+
+   {{</ notice >}} 
+
+2. In **Composing App**, click the app you just created.
+
+3. In **Application Components**, click **Click to visit** to access the app.
+
+   ![click-to-visit](/images/docs/project-user-guide/applications/create-a-microservices-based-app/click-to-visit.png)
+
+   ![dashboard](/images/docs/project-user-guide/applications/create-a-microservices-based-app/dashboard.png)
+
+   {{< notice note >}}
+
+   Make sure you open the port in your security group.
+
+   {{</ notice >}}
+
+4. Click **Normal user** and **Test user** respectively to see other **Services**.
+
+   ![review-page](/images/docs/project-user-guide/applications/create-a-microservices-based-app/review-page.png)
+
+