Container Lifetime & Persistent Data

• Containers are usually immuitable and ephemeral

• “immutable infrastructure”: Only re-deploy containers, never change

• This is the ideal scenario, but what about databases or unique data?

• DOcker gives us features to ensure these “seperation of concerns”

• This is known as persistent data

• Two ways: Volumes and Bind Mounts

• Volumes: make special location outside of container UFS

• Bind Mounts: link container path to host path

Data Volumes

• VOLUME command in Dockerfile

Bind Mounting

• Maps a host file or directory to a container file or directory

• Basically just two locations pointing to the same file(s)

• Again, skip UFS, and host files overwrite any in container

• Can’t use in Dockerfile, must be at container run

• … run -v /Users/caleb/stuff:/path/container