In this section you will modify the Dockerfile and then build the Docker image.

Modify a Dockerfile

We need to modify the following line in the Dockerfile (in Visual Studio Code):

    

        
        
            FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:7.0 AS build
        
    

to

    

        
        
            FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build
        
    

Ensure the Docker image will be built for the current platform, which is arm64 (alternatively, you could set the BUILDPLATFORM environment variable).

Then, you save the file and go back to the WSL console, where you type:

    

        
        
            cd People.WebApp/
        
    

You can now build the Docker image using the docker build command:

    

        
        
            sudo docker build -t people.webapp:v1 .
        
    

Then, type your password, and you will see the Docker build progress: Image Alt Text: command prompt#left

Figure 19. Building a Docker image

Note

In the above example, we used the -t flag to tag the image (people.webapp:v1). Also, we used . to set the build context to the working directory.

If you see errors during the build, double check that you invoked the build command from the People.WebApp folder as shown in the figure above.

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