What does docker container provide

• Every application needs
  • a process to execute as this allocates CPU and RAM
  • a network interface for accessing the application
  • a storage space or mounts which will have os and other necessary contents
• As we have observed in the class all of the above were present in linux as well as windows server or vms
• Now lets login into container and explore. As we have seen container also has network interfaces, its own process treee which starts from pid1 and a filesystem from / (root)
  
• As of now container is an isolated area which has its own
  • process tree
  • network interface
  • file system
  • users

How are these created

• The isolations are created with the help of namespaces
  • process namespace
  • mount namespace
  • net namespace
  • user namespace
• The limitations or restrictions on isolated areas can be acheived using control groups
  
• Initially docker used lxc (linux containers) to create containers. LXC are part of linux kernel releases
• Docker has created a component which is called as libcontainer, which is a low level component to create containers using namespaces and cgroups.
• Refer Here this article