What is Docker:-
Docker is the advance version of virtulisation. Virtulisation is nothing but spillting and adding of resources for better use
Docker is an open source platform designed to create deploy and run application we can install docker on any os but it uses linux to run itself.
It is written in “GO” language. It performs OS level virtulisation also known as containerization
Why Docker:-
Suppose a development team create a application which they forward to operational team to deploy on the servers but it failed to run on operation site
Which doesn’t means application is not code well and error in it but it lags on some dependencies which the operation team doesn’t have for example it needs Java 16 but the operation team doesn’t have that dependency that’s why it is not running on the that site
Only Solution to this is the development team must transfer his whole system to operational team in which app runs which is not possible
At that time docker comes in picture docker makes the image of the container in which your application is running and you can transfer the image to anyone which contain the whole OS
We can only go through the theory of docker in part 1
1. Docker is the advance version of virtulisation
2. Containers is nothing but when the image is in running state it is called container
3. Container doesn’t have its own OS it uses the OS of your hardware or laptop
4. It provides all the dependency which is available on docker hub to run the application
5. Docker hub is the central repository just like GitHub
6. We can only change the container but not able to change the image
7. Before docker many users faces the problem is that particular code is running on the developer System but in the User’s System
Advantages of docker:-
1. No pre allocation of RAM as it use the resources directly from your computer whenever required
2. Less cost — → Efficient use of hardware resources
3.It is light in weight — -> doesn’t have anything of it’s own uses computer resources
4.It can be run on physical of virtual Hardware
5.you can reuse the image if the same work is also need to done by your friend you can send it to him
6.It took very less time to create container as compared to creating VM
Disadvantages of docker — —
1. It is not the good solution for GUI you need to work with the commands
2. Require the same OS on both the development and operational site
3.Difficult to manage large amount of containers
4.Docker doesn’t provide a cross platform compatibility if the application is designed to run on windows that it can’t run on linux. For eg:- Android app is not working on iphone because of the difference in OS
Architecture and commands will be discussed in next blog
Just click on link — -> Best playlist to learn docker in YouTube