Linux distributions (Linux distros)

Linux is an open-source: There’s lot of variations according to their usage

• Ubuntu
• Debian
• Alpine
• Fedora
• CentOS

Install ubuntu

Shortcut: $ docker pull ubuntu → $ docker run ubuntu

run automatically download and run image if not already downloaded from docker hub.

$ docker ps shows only running containers, while $ docker ps -a shows stopped containers as well.

Start a container and iteract with it

$ docker run -it ubuntu opens a shell

root@ccbf220836a0:/#
root: user id
ccbf220836a0: machine id
/: current directory
#: Show highest privileges in linux since we logged in as a root

root@ccbf220836a0:/# echo hello
hello
root@ccbf220836a0:/# whoami
root
root@ccbf220836a0:/# echo $0
/bin/bash  # Show location of the shell program
root@ccbf220836a0:/#

Linux is case-sensitive system → Echo $0 will not work

Managing packages

Package managers

• npm
• yarn
• pip
• NuGet
• apt (advanced package tool)

May have tones of packages in this database, but not all of them are installed.

# apt install vim
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package vim

# apt list to see all the packages

# apt update to update package DB (Before installing package, always update package DB)

# apt -y install vim to install vim from updated package DB. (-y to yes to confirmation)

Linux file system

Hierarchical system

• /
  • bin # binaries and programs
  • boot # everything needed for booting
  • dev # devices
  • etc # editable text configuration
  • home # Multiple users have home directory here
  • root # Home directory of root user
  • lib # Library fiels like s/w lib. dependencies
  • var # variable (files that needed to be updated frequently like log, application data)
  • proc # running processes

→ In Linux, everything is a file including directories, devices, processes.

Windows

• C:
  • Program files
  • Temp
  • Windows

도커에 우분투 20.04 이미지 인스톨

$ docker run  -d -t --name ubuntu ubuntu:20.04

• Run contatiner (want exit? —> $ exit)

컨테이너 시작

$ docker exec -it ubuntu bash

• Version check

컨테이너 버전 확인

$ cat /etc/os-release

• Check running container

실행중인 컨테이너 확인

$ docker ps

• Stop container

컨테이너 스톱

$ docker stop [container_id]

• Check stopped container / checking deleted container

멈췄거나 삭제된 컨테이너 확인

$ docker ps -a

• Delete container

컨테이너 삭제

$ docker rm [container_id1] [container_id2]

• Currently installed images check

현재 설치된 이미지 확인

$ docker images

• Delete image

이미지 삭제

$ docker rmi [img_id]

• Delete container b4 deleting image

컨테이너 지우고 이미지 삭제

$ docker rmi -f [img_id]