Docker Article

Introduction

Docker is a set of coupled software-as-a-service and platform-as-a-service products that use operating-system-level virtualisation to develop and deliver software in packages called containers. The software that hosts the containers is called Docker Engine.

The Docker Engine was first started in 2013 and is developed by Docker. It is written in the Go language. Solomon Hykes pioneered the founding.

Containers in Docker are isolated from each other and bundle their own software, libraries and configuration files; they can communicate with each other through well-defined channels. They are run by a single operating-system kernel and are thus more lightweight than virtual machines.

Features

Easy and Faster Configuration - Code can be deployed in less time and with less effort. As Docker can be used in a wide variety of environments, the requirements of the infrastructure are no longer linked with the environment of the application.

Increase Productivity - By easing technical configuration and rapid deployment of application. Docker not only helps to execute the application in isolated environment but also it has reduced the resources.

Application Isolation - It provides containers that are used to run applications in isolation environment. Each container is independent to another and allows us to execute any kind of application.

Swarm - It is a clustering and scheduling tool for Docker containers. Swarm uses the Docker API as its front end, which helps us to use various tools to control it. It also helps us to control a cluster of Docker hosts as a single virtual host. It's a self-organising group of engines that are used to enable pluggable backends.

Routing Mesh - It routes the incoming requests for published ports on available nodes to an active container. This feature enables the connection even if there is no task is running on the node.

Services - These are a list of tasks that let us specify the state of the container inside a cluster. Every task represents one instance of a container that should be running and Swarm schedules them across nodes.

Security Management - It allows us to save secrets into the swarm itself and then choose to give services access to certain secrets. It includes some important commands to the engine like secret inspect, secret create etc.

Pros/Cons

Docker has its pros and cons:

Pros	Cons
Docker On Mac and Windows are better than ever - Docker is getting more and more mature by the day, especially as more developers are turning to it for the development and production environments. Docker for Mac and Docker for Windows reduces much of the complexity of leveraging Docker on non-Linux environments through abstraction. It now works as simply as any other application in your environment -- install it in the same fashion as your other tools like your text editor and browser -- and you are off to the races.	Docker has some gaps in documentation - Docker is moving at a fast pace and it is very hard to keep up with the latest advances and changes. While there is some fantastic documentation, there seem to be some gaps specifically within the docs for the abstraction layers.
Docker gives you consistency across your team - Another aspect of Docker that I love is the reliability that you have the same setup as your team. This is great for a couple of reasons: There is so much value in being able to run with the assumption that your entire team is using the same setup, and it enables you to run scripts and processes that will empower your entire development team to perform common operations with a simple command.	Docker has performance problems on non-native environments - Despite Mac being based on the native Unix layer. Docker still requires the actual Linux kernel in order to perform its operations. What Docker provides for Mac provides for you is an abstracted VM containing the Kernel, which you never interact with directly. You will interact with the containers within that VM, but they are networked together with your host in a way that you will rarely need any information about the VM itself.
Docker speeds up the provisioning process - You can avoid wild goose chases by providing all you need from within the docker container, potentially using a set of shared ssh keys, or requiring users to use personal keys on an identity service (can be impractical for some teams though).	There can be a significant learning curve to migrating to Docker - Learning Docker is a significant time sink. There are a lot of concepts that are just different enough from a Virtual Machine (VM) infrastructure to cause confusion and make unlearning concepts from other areas a bit more of a challenge, even for experienced developers.
They work well in DevOps and CI/CD - Container based Virtualisation are a great option for Microservices, DevOps, and continuous deployment since it is easy to manage them.	Security - Since there is no full operating system, people tend to overlook the security aspect of containers, but if you look up online, you will see that hackers are targeting systems that are hosted in containers and not secured properly.

Extra Programs

Related Features to Docker are below:

Front End Web Dev - HTML, CSS, JS
Front End JS Frameworks - ReactJS, Vue.js, Angular
App Development - Web Apps, Native Apps, IOS, Android, Windows
Testing Methodologies and Software
Alternatives to Docker - BSD Jails, LXD, LXC, RKT, Solaris Zones

Sources

Summary

In conclusion:

Docker is a exciting up and coming technology that enables the user to develop and distribute software via packages called containers, this can be very useful in the long run, especially for web and mobile applications. It can be used on different operating systems and Virtual Machines. IF you are planning on developing apps, please do your research on Docker.