chp 4:

• you can use multi-stage docker files, to build, test and start your application and copy files between each stage
• not in this chapter but I was curious if you can have docker watch files for changes then build and looks like docker compose has a watch option
• with multi-stage you don't need your build tools to be in with your app run, so the app run part can be even lighter and quicker
• when you need multiple containers to communicate with each other they do it through a virtual networking that docker manages. the IPs allocated on container creation by docker
• docker network create nat - create a docker network, called nat
• containers on the same network can reach each other by name by including --network nat to the container run command, nat is the network name
• benefits of multi-stage Dockerfiles
  1. standardization
  2. performance: layers are cached
  3. lean: only what is need is in the app