Docker – An Open-Source Container Technology

Docker is an open source software platform. It creates, deploys and manages virtualized application containers on a common operating system. Docker Inc. originally developed this software. It supports a commercial edition also and is the principal sponsor of the open source tool.

Docker is an open platform for developers and system administrators to build, ship, and run distributed applications on laptops, data center VMware’s, or cloud as per requirement.

Docker makes it easy to package and ship programs.

Docker packages the software and runs it independent of the OS. The container makes available all the required libraries, configuration files, dependencies and other necessary parts to operate. Each container shares the services of one of the underlying operating system.

Google also has its own open-source, container technology. Whenever you use some of Google functionality like Search, Gmail, Google Docs, you will be issued a new container.

Docker was designed originally to work on the Linux platform, but also supports non-Linux operating systems. Now it is also available on Microsoft Windows, Apple OS X,  Amazon Web Services and Microsoft Azure versions.

Advantages:

Docker permits a high degree of portability so that the users can register and share containers over various hosts in private and public environments. Docker has its own file system, storage, CPU, RAM. Containers use shared operating systems. It means they are much more efficient than hypervisors. Other benefits are efficient application development, lower resource use and faster deployment as compared to VMware.

The main difference between a container and a VMware is that while the hypervisor abstracts an entire device, container just abstract the operating system kernel. This means that hypervisors can do what containers cannot, is to use different operating systems or kernels. Hypervisor is a computer software, firmware or hardware that creates and runs virtual machines.

Disadvantages:

The efficient management and security of so many containers may provide difficulty. Although container and the OS are separate but any problem in the OS may compromise the container. That is why, some organizations run container within a VMware, but virtual machines are not required here.

Features:

• Easy and Faster Configuration – The system can be configured easily. Docker can be used in a wide variety of environments.

• Increased productivity – Docker has reduced the resources, that helps to execute the application in an isolated environment.
• Application Isolation – Each container is independent of another that permits to execute any kind of application.
• Swarm – Docker swarm mode in Docker Engine supports cluster load balancing for Docker. Multiple Docker host resources are pooled together to act as one with Docker swarm mode. It enables users to quickly scale up container deployments to multiple hosts.
• 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 – It provides a list of tasks that help us specify the state of the container inside a cluster. Each task represents the running of one step of a container and Swarm makes their schedule across nodes.

• Security Management – This saves the secrets in the swarm and then decides to give service access to some secrets like secret inspect, secret create etc.

Conclusion:

Docker can get more applications running on the same hardware than other technologies. It makes it easy for developers to quickly create ready-to-run container applications that makes managing and deploying of applications much easier. Companies are seriously considering to move their server applications to Docker.