Docker, say what?
As the logo resembles, docker analogically is a shipping dock where one loads on multiple containers and ships the goods where and when required. So, containers in technical sense are the bucket that contain apps. Each container is oblivious to what other container has, no damage whatsoever. According to docker’s official site: Docker is an open platform for developing, shipping, and running applications. Docker enables you to separate your applications from your infrastructure so you can deliver software quickly. If one needs a simple one liner about what docker is, then one can say: Docker is like virtual machine system. But, if one concludes saying just this; then surely there are people who will rip you because there are a few or should I say more than few differences.
Why Docker?
Why Docker begs the question:Â Why not VirtualMachine? Let’s illustrate this by an image.
Docker is based on the container architecture. And, the best thing about it is: containers use shared operating system which virtually is efficient than hypervisor architecture. The useless VM junk that is of little to no need, why not getting a capsule for each of your application. Basically, what I mean is: create containers that contain your app and rather than using VM’s that utilize much system resources without having that much effect on regular basis.To put in a nutshell, containers are smaller than Virtual Machines and enable faster start up with better performance, less isolation and greater compatibility possible due to sharing of the host’s kernel. Dependency issues faced during production give headaches more often than not, which docker resolves by the use of encapsulated containers that are preloaded with dependencies.
What comprises a docker engine?
Docker Engine is what we use to develop docker images, develop, push ,etc. you might wonder what docker images? Docker images have a big say later on. Docker engine contains:
- A server which is a type of long-running program called a daemon process.
- A REST API which specifies interfaces that programs can use to talk to the daemon and instruct it what to do.
- A command line interface (CLI) client.
The docker engine can be virtually described by the figure below:
Docker Images and Containers
An image is a snapshot of a container. Images are created by build command and they’ll produce a container after the run command. An image can be large so to minimize such criteria, images are and should be designed to be composed of layers of other images, allowing a minimal amount of data to be sent when transferring images over the network. Containers in context of programmatic metaphor: is an instance of a class if the class is an image. Containers are basically the reason why Docker is so popular; they’re lightweight and portable encapsulations of an environment in which to run applications.
So, for now this is where it ends about a quick glance to Docker. But, we are happy to report you that we have setup a docker registry server within Javra but yet there are possibilities we cannot yet fathom. We will soon post the tutorials for the setup so and so.