Docker

Docker is used to run software packages called "containers". Containers are isolated from each other and bundle their own tools, libraries and configuration files; they can communicate with each other through well-defined channels 
                                                                                              --Wikipedia 

I have already written a article about the containers you can check out in here https://thangaayyanar.blogspot.com/2018/06/containers.html

This time, let's learn more about docker engine how we can use this. The important things we need to know in docker are

Docker Image:

 The container can be created with the help of Image.

The Image file consists of

• code,
• libraries,
• environment variables,
• configuration files

 It is like a blueprint, if you know about Object Oriented Programming Language - It is similar to class

containers are instance of image

you can able find ton of images in dockerhub ( just like github for open source software ) which is maintained by docker

you can able to pull the image from dockerhub using

docker pull [image_name]

docker pull [image_name:tag]

[or]

If you want custom docker image,you can able to do that using the dockerfile

find the images you have downloaded using

docker images

Docker container:

To create a container from run

docker run --name [name_for_container] -it [image_name]

-it => create a pseudo tty to interact with container

Note: 

• Before you run a image best check the image docs on how to start the specific docker image.
• Sometimes you need to expose port if the image contain server or other services.
• you can run the container in background ( add -d option while starting the container )

you to start container using

docker start [container_name]

and stop using

docker stop [container_name]

To interact with docker container with

docker attach [container_name]

To check the containers created and running containers using

docker ps -a

These are the basics things that is necessary get and run docker container other than that we have

Docker compose file - where we can configure your container and how much container need to started,..

Docker swarm - group of machine running docker to form a cluster simply multi-conatiner with multi-machine

Got excited need to learn more, follow the link below:

https://docs.docker.com/get-started/