Few names in the API world are as well known as Docker. Docker has become a popular open source platform for developers because it can provide API users with a complete development ecosystem from a single application.

The popularity of Docker is not hard to understand. Docker is an easy-to-use system that combines code, execution, system tools, and libraries — basically everything you can install on a server. So, it makes it easy for developers to create, deploy, and run applications.

Docker101: Put everything into containers

So what exactly is a Docker? Simply put, Docker is an implementation of a lightweight Linux container that allows virtualization of an environment containing its own processes and network space. Docker automatically deploys applications in these software containers by providing additional abstraction and virtual automation at the operating system level. Instead of creating a full virtual machine, these containers simply sit on top of the same Linux instance and provide a small space within which applications can run.

One of the best features of the Docker container is that it allows developers to package everything an application needs, including libraries and additional dependencies, and then distribute it as a separate package. By packaging applications this way, you no longer need to run a single virtual machine, which means you can deploy as many applications as you want to distribute on one of your Linux hosts. And because you no longer need to add a virtual machine for every application, you actually have more processing power at your disposal — you can use it to arrange more containers or deploy other applications that you want to run.

Simplify API development

As we mentioned above, Docker provides a complete development ecosystem to API users in a single application, which greatly simplifies the API system in the running environment. Each Docker container contains only one application and all its dependent files, and shares the same kernel with other application containers on the same host system.

This means that the container can be used freely on any system, even without the usual contents of a virtual machine’s operating system — including binaries and libraries. Thus, such an API system only needs to contain what it really needs.

Why Docker? Because there are so many benefits

With so much background explained above, what exactly makes Docker a really good choice? The main reasons are as follows:

It’s open. Because Docker’s open standards have the great advantage of being compatible with Linux and Microsoft operating system environments, it can support most infrastructure configurations, and it also allows transparency into the code base.

It’s safe. In the traditional model, breaking an API application can easily cause problems for the whole system, but unlike the traditional interdependent model, through the use of Docker containers, we can achieve the isolation of each application being processed from other applications. If you have a Web API deployed in a Docker container, you can also force HTTPS to be used as additional encryption. Moreover, because Docker is an open system, Docker users will regularly check the system for security loopholes. In addition, you can also access more Docker-related tools and exercises by visiting Docker Security Center.

It reduces development time. Docker containers are fairly simple to build, start, and save images. It also makes it easy to migrate an existing image to an existing Docker container. Also, because the development ecosystem is packaged, you can spend more time writing code than managing and maintaining the environment your application needs.

It uses common file systems and mirrors. Docker deploys common file systems and images and shares the base kernel for API applications. Therefore, after using Docker, API applications containing multiple dependencies can reduce redundant dependencies and free up more space by consuming system resources. At the same time, the container of this API program will be easier to use and understand.

Give it a try

In summary, Docker is a fairly simple and easy-to-use technology. Docker can be created automatically by reading instructions in a Dockerfile: a text document that contains all the instructions you can call on the command line to create an image. With Docker build, you can create an image that automatically creates new images by executing several command line commands.

The docker build command creates an image by specifying the Dockerfile and environment at a specific location, PATH or URL. PATH is the directory of your local file system, and URL is the location of your Git repository. Using a simple create command in the current directory:

$docker build. Sending build context to docker daemon 6.51 MBCopy the code

If you want to use a file in your creation environment, the Dockerfile directive points to that file, similar to the COPY directive. If you want to improve its performance, you can exclude files and directories from your current directory by adding a.dockerignore file.

Dockerfile is in the current root directory. You can point to dockerfiles anywhere in your file system by using the -f flag of the Docker build.

You can also specify a repository and table where you want to save a new image by providing a create command:

$ docker build -t shykes/myapp .Copy the code

The Docker daemon will run your steps, submit you a new image with its ID, and automatically clean up the associated environment.

For more in-depth discussion of Docker and new sample directives, you can visit this Docker online tutorial.

Sheena Chandok is the author of this article

Foreign languages:Docker: A Simple, Powerful Approach to APIs

This text is from:Code site