What is Docker?
Docker is a platform used to containerize your software, using which you can easily build your application, the package with the dependencies required for your application into the container further, these containers are easily shipped to run on other machines. Docker is simplifying the DevOps methodology by allowing developers to create templates called images using which you can create a lightweight, virtual machine called a container.
Docker is making things easier for software industries giving them the capabilities to automate the infrastructure, isolate the application, maintain consistency, and improve resource utilization.
Key Feature of Docker
- Easy configuration: This is one of the key features of Docker in which you can easily deploy your code in less time & effort as you can use Docker in a wide variety of environments. The requirement of the infrastructure is no longer linked with the environment of the application helping in configuring the system easier and faster.
- You can use swarm: It is a clustering and scheduling tool for Docker containers, SO swarm used the Docker API as a frontend which helps us to use various tools to the controller, it also helps us to control clusters for Docker host as a single virtual host, it is a self-organizing group of engines that is used to enable, pluggable backbends.
- Manages security: Docker allows us to save secrets in the swarm itself. And then choose to give services access to certain secrets. It includes some important commands to the engine like secret inspection, secretly creating, etc.
- Services: Service is a list of tasks that lets us specify the state of a container inside of a cluster. Each task represents one instance of a container that should be running and Swan schedules them across the nodes.
- More Productivity: By easing technical configuration & rapid deployment of applications no doubt it has increased productivity, Docker not only helps to execute the application in an isolated environment but also reduces the resources also.
Docker Advantages
- Build app only once: An application inside a container can run on a system that has Docker installed. So there is no need to build and configure apps multiple times on different platforms.
- More sleep and less worry: With Docker, you test your application inside a container and ship it inside a container. This means the environment in which you test is identical to the one on which the app will run in production
- Portability: Docker containers can run on any platform. It can run on any local system, Amazon EC2, Google Cloud, Virtual Box, etc.
- Version control: Like git, Docker has a built version control system. Docker containers work just like GIT repositories, allowing you to commit changes to your Docker images and version control them.
Docker Disadvantages
- Missing feature: It has got Missing features. There are tons of features that are under progress like container self-registration, self-inspect copying files from host to container, and many more.
- Data in the container: When the container is going down after that it needs a backup and recovery strategy although we have several solutions for that they are not automated or not very scalable yet.
- Graphical app: Docker was designed as a solution for deploying server apps that do not require a graphical interface, while there are some creative strategies such as x11 video forwarding that u can use to run GUI apps inside the container.
- The benefit is few: Generally, only apps that are designed to run as a discrete set of microservices stand to gain the most from containers, otherwise, Docker’s only real benefit is that it can simplify application delivery by providing an easy package machinima.
Kubernetes vs Docker
Pre-requisites: Kubernetes, Docker
Docker is a platform for containerization, while Kubernetes manages containers for numerous container runtimes. There are various container runtimes supported by Kubernetes. Some are
- Docker
- Containers
- CRI-O
- Mirantis Container Runtime