How Docker containers Work

• Refer Here to understand how containers work
• To Make contianers work linux uses
• Isolations are created using kernel feature called as Namespace
• Resource limits are applied using kernel feature called as cgroups

Docker Engine (Earlier Versions)

• In ther earlier versions Docker used to rely on lxc to create container.
• LXC was part of linux releases, any feature changes used to impact the docker containers.
• Docker has built a project called as libcontainer and the the goal of libcontainer was to provide Docker with building blocks that exist in the host kernel to create containers.

Open Container Initiative (OCI)

• While docker was trying to refactor the code of docker daemon, The OCI standards came up with two specifications
• Image spec Refer Here
• Container runtime spec Refer Here