Run and debug Docker projects in Fast mode

When you run or debug Docker applications from JetBrains Rider, it uses a Fast mode by default. Docker Fast mode builds and launches the application directly, without the need to build and publish the container. In this mode, only the base stage of the Dockerfile is executed; build, publish, and final are ignored.

When running in Fast mode, JetBrains Rider builds the project outside the container and mounts it inside the container via bind mounts. The mount location inside the container is specified with the DockerFastModeProjectMountDirectory project property. If this property is undefined or invalid, JetBrains Rider will create and mount the /app directory for that.

The only benefit of the Fast mode is that the application startup from the IDE happens significantly faster. As soon as the application is running, there will be no difference in performance.

If you need to test your application in exactly the same way as it will run after the deployment in a Docker container , you can disable the Fast mode: open the corresponding run configuration, click Modify options and choose Don't use Docker Fast mode.

Another way to disable Fast mode for a specific project is to use <ContainerDevelopmentMode>Regular</ContainerDevelopmentMode> property in the project file.