What is Docker
This is a special service that was invented for containerization, during which you can develop applications differently and carry out other work with them. Thanks to Docker, this becomes possible; you can package the program along with other elements in so-called containers. The latter guarantee uninterrupted operation of the application, which does not depend on the environment in which it needs to run.
Containers are lightweight, decoupled environments that allow applications to run faster and with fewer resources. This is why Docker has become an excellent tool for improving business processes and continues to grow in popularity. It can solve the vast majority of incompatibility problems (for example, between different settings).
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Companies often wonder what Docker is and why it is needed, especially when it comes to speeding up development processes. Thanks to Docker, it becomes possible to create applications that will later work equally well on different platforms.
To understand what Docker is, Let’s look at how it affects many processes. For example, it becomes possible to separate the application from the operating system and thereby ensure its portability.
Features of containers
These are self-sufficient environments that can ensure the correct operation of the program. The speed of container operation remains at a record level.
A Docker container is an identical image, but is able to run in a dedicated space. This means that possible failures in the simultaneous operation of several programs will be reduced to zero, and they will not affect each other in a negative sense.
It is also worth paying attention to the fact that the containers are “light”. This term means that Docker container does not require a lot of disk space and also does not require many additional resources. This is made possible by using the shared memory of the host systems.
When the question arises of how to create a Docker container, you can see that the process is not complicated and intuitive. It is only important to decide on the basic template, settings and required dependencies. After settings, the container is considered completely self-sufficient and suitable for testing and introducing updates.
Core Docker Components
To understand the principles of effective work with the platform, it is worth understanding its key elements. The following Docker components are responsible for all stages of creating and running containers and are designed to simplify working with applications. The list is as follows:
- Docker Engine. The main place (kernel) in the system can manage containers. Thanks to the module, you can separate processes from each other and correctly distribute resources.
- Docker Hub. This is where images are stored and where they can be shared.
- Docker Compose. Specifically designed for the application and with a large number of containers. Compose allows you to customize how they interact with each other.
- Docker CLI. It is a command line and helps manage containers and many other elements of the system.
The use of Docker in business is considered ubiquitous due to its ability to provide application scalability. The service helps simplify application deployment and reduce errors to zero. Companies also benefit from saving their own time resources.
How does a Docker image work?
The Docker image is needed as a base to create containers and has many layers, which makes the work easier. Thus, each layer makes a specific change, which may include, for example, installing an operating system.
The appeal of the idea is that the layers are kept separate. And in the event that different containers use the same layer (such as, for example, an operating system), then Docker will store only one of the copies and thereby save disk space.
Using Docker makes things easier because you can act intuitively. For example, a new image can be created by adding only the necessary components to an existing one. Thus, many processes are simplified, and time for reassembling the entire image is saved.
Creating a Docker image
This is an important step when working with the platform. Having an understanding of how to build Docker can simplify many business tasks and make application development and deployment easier to understand.
The creation procedure is as follows:
- Working on the Dockerfile needed to list the steps to create an image. It is worth specifying the base image, the directory for work and the actions that are required to be performed within the image.
- Save file. After writing it, the file must be saved in the root folder of the project and done so with the correct name – “Dockerfile”. This is necessary to automatically recognize it.
- Use CLI tool for build purpose. During the process, it is important to specify the base image, recommended files to add, and configure the working environment. It is important to name the images with clear names to make things easier.
- Check the result. After completing the above steps, it is important to review the list of available images. Basic information about the created image should be visible there. This way you can be sure that the work was done correctly.
- Test functionality. It is important to test the project by running the container. Having completed this step, you will be confident that the application inside the image works correctly.
Services for working with containers
- Docker Compose. This is a service that can simplify the management of applications that have more than one container. It makes it easier to describe all containers and their mutual influence on each other in one file. This can be especially useful for applications that require the operation of several components at once.
- Kubernetes. It is a system that automates deployment and distributes the load between containers. Kubernetes will help you work more efficiently with complex projects where precise and flexible control is important. Also, in the event of a failure, the program can automatically restore data.
- Docker Swarm. The tool helps orchestrate containers in Docker. Thanks to Swarm, it becomes possible to combine different servers into clusters and then manage them together. The program will be useful for companies that want to manage entire groups of containers simultaneously and without additional tools.
How to install Docker
This is the first step in working with containers. This is easy to do and takes minimal time. Docker works equally well on Windows, macOS and Linux. Below we will look at how Docker is installed.
On Windows and macOS
For these systems, just download Desktop – the official application, which includes all the necessary tools. You can download it from the official website, install it on your device and then follow the instructions. Desktop will make it easier to manage containers through a graphical interface.
And Linux
When wondering how to install Docker on Linux, it is better to turn to package managers. You should add the official Docker repository and download the program in the standard way.
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After installation on your device, check that the system works correctly.
Running a Docker container
For the process to be successful, you need to correctly prepare the system, which includes Docker, installation and configuration. It is also important to choose the right image.
Immediately before starting it is important:
- Check if the required images are available.
- Check that the parameters are configured correctly.
- Check whether the necessary resources are available to the containers.
During the process you should pay attention to:
- Resource limitations (for example, memory and processor).
- Communication with other containers.
- Saving master data.
Setting parameters during startup ensures that containers are better adapted to specific tasks.
Correct Docker configuration is the basis for stable operation.
Benefits of using Docker
- Speedsince the container can start in a matter of seconds. This happens because there is no need to emulate the hardware environment. Thus, application development and deployment are greatly accelerated.
- Scalabilitysince there are no barriers to load growth. The system becomes flexible and resistant to traffic changes, and ensures reliable and stable operation.
- Versatilitysince the system is capable of operating in a wide variety of conditions. It can run on developers’ local computers, or in the cloud or on servers. The process of transition between development stages is simplified and problems are minimized.
- Efficient use of resourcesbecause when using the system, less memory is required, as mentioned above.
- Securitysince isolation in containers makes data leakage less likely. The likelihood of a failure or attacks on one of the containers is reduced to zero.
Bottom line
Docker is a useful tool designed to make application development easier. By working together, companies gain more flexibility and stability.
With containerization, applications can run predictably and efficiently, regardless of the operating system or server configuration.
Understanding how to run a Docker container will help optimize many business processes.
Cover photo: Freepik
Source: rb.ru
