As mentioned earlier in this chapter, the App Engine flexible environment is an attempt to find some middle ground between the flexibility of traditional virtual machines and the convenience of the App Engine standard environment. Developers are able to assume control over the underlying infrastructure when needed, and fall back on the more traditional aspects of a managed platform when control is not needed.
There are a number of advantages of using the flexible environment over the standard environment. The following are a few of the major benefits, though the list is not comprehensive.
In the flexible environment, each service is packaged as a Docker image. App Engine runs services as containers based on these images, each running in a dedicated Compute Engine VM. This provides developers with three levels of infrastructure to manage applications—the application layer, the container...