Introduction

this is part 7 from the journey it's a long journey(360 day) so go please check previous parts , and if you need to walk in the journey with me please make sure to follow because I may post more than once in 1 Day but surely I will post daily at least one 😍.

And I will cover lot of tools as we move on.

Back to Hello World demo

in part 6 we run

docker run Hello-World

As we see in 1 the docker client contacted the docker daemon as we discussed earlier

in step 2 the docker doesn't find the image hello-world locally so he go to the docker hub and downloaded for us!

see how easy it is with one command we got an image!

in step 3 the Docker create a new container using the image we downloaded and run it so we got this output

in step 4 the deamon (server) send back the message to us ! (client)

Docker Image and container

If you are a programmer and you study OOP(Object Oriented Programming) we can think about Image as an Class ,

and the container is an instance of it kind of

Car tesla = new Car();
Car toyota = new Car();

We can imagine the Image as the Car and the Container as tesla and toyota , see I build on top of 1 Image 2 Containers and there is no need to pull image again from dockerhub so it will skip step 2!

let's run an light linux system (alpine)

docker run -it alpine sh

-it stands for i is interactive and t is an pseudo-TTY (pseudo terminal to communicate with bash)

alpine is a light linux distro which contain basic files and kernel to run linux

sh is kind of a bash

as we see , docker doesn't find the alpine locally , so he pull it from docker hub

as we see home directory is empty (home directory is linux folder like D: in windows you can locate personal files not system files)

mkdir (make directory is a linux also windows command to make a directory) and test is folder name

as we see when I restart the docker , I lost the changes I made !

this will be covered later.