About Docker

Docker is a open source solution that is based container management service. The main purpose of docker is to increase the productivity of developers and dev-ops with less error pron. Docker provides a robust client server app architecture with a strong server, REST API and command line interface client. We can follow the same steps to run more containers and utilize fewer resources.

Docker installation on ubuntu

Open a terminal window and type to update repositories:-
> sudo apt-get update

Uninstall Old Versions of Docker if exist:-
> sudo apt-get remove docker docker-engine docker.io

To install Docker on Ubuntu, please follow:-
> sudo apt install docker.io

Start and Automate Docker:-
> sudo systemctl start docker
> sudo systemctl enable docker

Check docker version:-
> docker --version

Setup Postgres Image and container:-

Firstly we need to pull postgres image on our local machine from docker hub. To do that simply we need to run this command:-
> docker pull postgres

To check all exist docker images:-
> docker images

Start postgres instance:-
> docker run --name postgres-0 -e POSTGRES_PASSWORD=mypassword -p 5433:5433 -d postgres

Now we can check docker all running container by this command:-
> docker ps

Connect and run queries:-
> docker exec -it postgres-0 psql -U postgres

Create database:-
> CREATE DATABASE ps_database_1
Connect with database:-
> /c ps_database_1
Create table:-
> CREATE TABLE table_1(something int);
> INSERT INTO table_1 (something) VALUES (1);

Some useful commands for docker

To check docker version:-
> docker --version

To download docker image:-
> docker pull image_name

To list of all exist images on your machine:-
> docker images

To run docker image:-
> docker run -it -d image_name

To check what is running in docker:-
> docker ps

To list all docker running /exist/stopped with container info:-
> docker ps -a

To access docker container:-
> docker exec -it container_id bash

To remove docker container:-
> docker rm container_id

To remove image:-
> docker rmi image_id

To restart docker:-
> docker restart container_id

To stop docker container:-
> docker stop container_id