Docker! Build Ship Run!
Hello Folks,
With this post we are going to learn about;
- What is Docker?
- How it works?
- What problems does Docker solve?
And also we are going start thinking about using Docker in our projects ;)
Let's start!
What is Docker?
Docker is a great solution of virtualization to implementing, transferring and running your applications.
So, virtualization is great but what is making Docker so good?
Docker is a virtualization solution but it differs from other ones in a great way. Docker runs applications in a container so instead of re-installing the whole operating system you just start a new container and voila! Docker just defined a new category, which is containerazation :)
Docker is the world's leading software containerization platform.says in Docker.com
Why containerization is so important? What is the big deal?
To answer that question we should go back in time... to 50's..
In April 1951 some of the world's leading countries gathered together and decided a standart container.
Nowadays it seems not so important to us. But after that simple standart logistics industry grown exponentially! Until that consensus we had following problems :
- What if my coffe beans be smashed under the piano on the same ship?
- If my product/application be affected from other product/application
- Should I need any other tool to load my coffe beans into ship?
- Any other tools needed to install my product?
- What if one of my coffe bean sacks lost or mixed with another sack?
- If there will be a difference between production environment and development environment?
With containers we solved all problems above. After the container usage people only needed to place their products into well known metal box (container). The rest is easy transfer of the container have a consensus all over the world.
Seperation of Concerns take place here. You all need to load your thing on that container the rest is standartized process.
That is also Docker's way.
Docker is providing standartized container, once you load your application you are able to run and transfer it easily. With docker you don't need a new ship for your application to have a isolated environment you just need a container.
I see the value of Docker. But how does it work?
Docker is based on a Linux technology which is Linux Containers (LXC) it introduced in 2008 and then included in Linux kernel. LXC, is providing different root path, environmental variables other needed functions for every container. By doing so the containers thinks the whole operating system belongs to them. You may find more information about LXC here
Docker used that technology to eliminate the need of "Guest OS" by doing so Docker provided valuable resources back to us. The other virtualization platforms needs a guest os on top of host os as seen below,
With that approach we have the valuable resources avaliable for other containers. If we do a simple math; for 10 virtual environment we should allocate 2 GB of ram for each and 10's GB of disc space. Use Docker and have that 20 GB RAM and 100 GB of HDD back :)
Oh by the way, you can use Docker in Windows, Linux and MacOs. So don't hesitate if you are not using linux.