Docker

Introduction
Linux and Networking
Commands
Resources

Introduction

Crash course
- Exploring Docker [1] - Getting Started
- Exploring Docker [2] - Docker Compose With Node & MongoDB
Docker in 100 secs
Aim: To run software services/progs/applications inside containers.
Eg: Apache, MySQL, MongoDB, NginX (web server common to Apache), Wordpress, etc...
Advantages: Convenient, fast, simple, easy to re-create the same environment.
Docker Hub == GitHub of Docker

NOTE:

Docker Desktop for Windows Home is here!

For Win 10 Home (2004 and above), Pro and Enterprise, install Docker Desktop.

For Win 10 Home 1909 and lower, install Docker Toolkit.

Docker might not work on VSCode integrated terminal. In that case, open VSCode as an administrator, use ext cmd or use powershell.

Some commands might not work in cmd. Use Powershell in that case.

$(pwd) in MacOS is $(%cd%) in Cmd and ${PWD} in Powershell

localhost:port might not work. Use 198.168.99.100:port instead.

Container privileges

Network privileges might be required sometimes

All privileges

Linux and Networking

Please refer to linux-networking.md.

Commands

Miscellaneous Commands

docker version
Server: Docker Engine (built on Go lang)
docker info

Images

To view images on local machine: docker images
To remove images: docker image rm ed2 (the entire image ID is not required)
To pull image from DockerHub: docker pull nginx
To build image
- docker image build -t harshkapadia/nginx-website .
  - harshkapadia/nginx-website = Docker_ID/img_name
  - . = refering to Dockerfile in currect dir (make sure your cmd is pointing to the correct folder)
To push image to DockerHub: docker push harshkapadia/nginx-website

Containers

To show running containers
- docker container ls
- docker container ps
- docker ps
To show all containers on the system
- docker container ls -a
- docker ps -a
To run container in the foreground
- docker container run -it -p 80:80 --name my_custom_name_for_nginx nginx
  - container = management command
  - run = sub-command
  - it = interactive terminal, ie, run in the foreground
  - -p or --publish = publish
  - 80:80 = mapping ports (portto_be_used_on_local_machine(useany_port):port_exposed_from_container- (use_default_port_of_service_in_container))
  - nginx = image name
- Once the img is downloaded:
  - localhost:80 or localhost (default is 80) or 127.0.0.1 (localhost)
  - Win 10 Home users (might not be needed with Docker Desktop): 192.168.99.100 (Since Toolbox is running a Linux VM in VirtualBox, localhost won't work. Use 192.168.99.100 (default) instead.)
- To stop container: ctrl + c
To run container in the background:
- docker container run -d -p 8080:80 --name my_custom_name_for_nginx nginx
  - -d or --detach = detached
- To stop container: docker stop my_custom_name_for_nginx or docker container stop my_custom_name_for_nginx
- To view:
  192.168.99.100:8080 (Win 10 Home users - might not be needed with Docker Desktop - localhost might work)
To remove container: docker container rm c699 (the entire container ID is not required) (deleting container does not remove the image from the system)
To remove running container:
- First stop the container and use the remove command
- OR use force: docker container rm c699 -f
To remove all containers on the system: docker rm $(docker ps -aq) -f (-f added to remove any running container(s) as well) (this ran in powershell, but not in cmd)
Env variables: docker container run -d -p 3306:3306 --name my_sql_user --env MYSQL_ROOT_PASSWORD=123456 mysql (you can find the env vars on Docker Hub)
To start a new container from an existing image: docker container run -d -p 80:80 --name custom_name_nginx nginx
To start an existing container: docker start <container_id>
To enter a container: docker container exec -it mynginx bash (start the container using the abv cmd before doing this)
- After entering:
  - To view file system: ls
  - To get to index.html (displayed on screen at port) (for nginx): cd usr/share/nginx/html
  - To come out of container: exit
  - To edit file, refer to the bind mount section below.

Bind Mount

NOTE: Ports 80 or 8081 might not work with below example. Use 8080, 8082, 8083...

To create container:
- With Docker Toolbox:
  - Refer to bind_mount.md for further details on 'x_drive'.
  - Make sure docker-machine is running (docker-machine start)
  - docker container run -d -p 8080:80 -v /x_drive/coding/docker/docker_basics/mounting_example:/usr/share/nginx/html --name - nginx-website nginx
  - Refer to files in the mounting_example folder.
- With Docker Desktop:
  docker container run -it -v "%cd%":/mnt --name kali kalilinux/kali-rolling