Definition:
Dockers is an open-source software platform to create, deploy and manage virtualized application containers on a common operating system (OS), with an ecosystem of allied tools. Docker Inc., the company that originally developed Docker; supports a commercial edition and is the principal sponsor of the open-source tool. It is also termed Containerization which means to is a lightweight alternative to full machine virtualization that involves encapsulating an application in a container with its own operating environment. It has gained recent prominence with the open-source Docker.
Types of Dockers:
A host volume lives on the Docker host’s file system and can be accessed from within the container; It can be difficult, however; to refer to the same volume over time when it is an anonymous volume, A named volume is similar to an anonymous volume. Docker manages where on disk the volume is created, but you give it a volume name.
Also Read: understanding of virtualization
Diagram
Theory:
Solomon Hykes started Docker in France as an internal project within dotCloud, a platform-as-a-service company, with initial contributions by other dotCloud engineers including Andrea Luzzardi and Francois-Xavier Bourlet Jeff Lindsay also became involved as an independent collaborator. Docker represents an evolution of dotCloud’s; The software debuted to the public in Santa Clara at PyCon in 2013. Docker was released as open-source in March 2013. On March 13, 2014, with the release of version 0.9, Docker dropped LXC as the default execution environment and replaced it with its own lib container library written in the Go programming language.
Benefits of Dockers:
ROI and Cost Savings: the biggest advantage of Docker is the return on investment. The more a solution can drive down costs while raising profits, the better a solution it is, especially for large; established companies, Standardization and Productivity: Docker containers ensure consistency across multiple developments and release cycles, standardizing your environment. One of the biggest advantages to a Docker-based architecture is actually standardization; CI Efficiency: Docker enables you to build a container image and use that same image across every step of the deployment process. A huge benefit of this is the ability to separate non-dependent steps and run them in parallel.
Demerits of Dockers:
Containers don’t run at bare-metal speeds. Containers consume resources more efficiently than virtual machines. But containers are still subject to performance overhead due to overlay networking, interfacing between containers and the host system and so on. If you want 100% bare-metal performance; you need to use bare metal, not containers. Although the core Docker platform is open-source; some container products don’t work with other ones — usually due to competition between the companies that back them. For example, OpenShif; Red Hat’s container-as-a-service platform only works with the Kubernetes orchestrator.