DevOps

Lab and Assignment For 25 Oct 2021 – Docker Session

Assignment# 1 – What is Docker and Container? Define in 15 points with example image

Container:

  1. Container in short a runtime of it’s own
  2. Runs in separate namespace isolated from host
  3. Has its own Root FS & USER space, PID tree, MNT and Network etc.
  4. This is not a bootable image like VM and BOOT FS is held with host itself.
  5. Its own quota of Resources like RAM, CPU etc would be Allocated through cgroups

Docker:

  1. Container manager SW that run on host OS
  2. Runs as daemon server and can orchestrate more than one container.
  3. would run in its own user group called “docker” and We can add Non-root users to docker group to run and manage containers and ensure security without needing rely on Admin/root users.
  4. provides complete set of toolkit to manage and tune containers
Assignment# 2 – What is the difference between docker pause and unpuase?
  • docker pause would just suspend current running processes in one or more container by saving their state and keeping Memory print still active.
  • When we unpause it would being back all suspended processes back to runtime by attaching the same memory and process state as before pause.

Assignment# 3 – What is the difference between docker stop and kill?
  • docker stop would gracefully terminate all running process by sending SIGTERM signal
  • docker kill do abrupt shutdown processes by sending SIGKILL signal