1. Understanding Docker images, file systems and containers The image of the container is a file after packaging and compiling the container. The packaging image depends on the Dockerfile file. The From line defines the starting content of the image, which is the basic image for construction. The process of building the image is to upload the entire directory of files to the Docker guardian During the process, Docker will first pull the basic image from the basic image warehouse, and then the packaging of the image is a layered structure, with the basic image as a layer, and then each command will be used as a new layer, layer by layer , the whole is a joint file system.

1. Comparison between monolithic applications and microservices Disadvantages of monolithic applications: run on several servers in the form of a single process or several processes, the deployment cycle is long, and the operation and maintenance and development are disconnected. After the developers complete the development, they are packaged into a whole for operation and maintenance deployment. There is no decoupling between modules. To modify a module, the whole package needs to be deployed.