Docker is an open-source platform for developing, shipping, and running applications, which enables developers to automate the deployment and management of applications within software containers. Docker simplifies the process of packaging software and its dependencies into containers, providing isolation, scalability, and efficient resource utilization. Containerization is now a standard practice in modern software development with Docker being one of the most widely used technologies.
With Docker you can separate your applications from your infrastructure and treat your infrastructure like a managed application. Docker helps you ship code faster, test faster, deploy faster, and shorten the cycle between writing code and running code. Docker does this by combining a lightweight container virtualization platform with workflows and tooling that helps you manage and deploy your applications.
At its core, Docker provides a way to run almost any application securely isolated in a container. The isolation and security allow you to run many containers simultaneously on your host. The lightweight nature of containers, which run without the extra load of a hypervisor, means you can get more out of your hardware. Docker has two major components:
Docker uses a client-server architecture. The Docker client talks to the Docker daemon, which does the heavy lifting of building, running, and distributing the Docker containers. Both the Docker client and the daemon can run on the same system, or you can connect a Docker client to a remote Docker daemon. The Docker client and daemon communicate via sockets or through a RESTful API.
The Docker daemon runs on a host machine. The user does not directly interact with the daemon, but instead through the Docker client.
The Docker client, in the form of the docker binary, is the primary user interface to Docker. It accepts commands from the user and communicates back and forth with a Docker daemon.
To understand Docker’s internals, you need to know about three components:
Due to the lightweight architecture of the docker and fast accessibility of the applications, Docker is gaining a rapid foothold among IT giants. As continuous access to the applications is the key in such environments, even the smallest degradation in the performance of the Docker would result in huge losses. To ensure the 24x7 availability of the Docker and high-performance rate, administrators need to closely monitor the performance and status of the Docker and its associated components, promptly detect abnormalities, and rectify them before services are affected and end users are impacted.
A Docker image is a package that contains everything needed to run software, while a container is a running instance of an image. The image is like a template, and the container is the actual running environment.
Users often share Docker images via container registries. A container registry is a centralized repository for storing and distributing Docker images. It allows users to upload, download, and manage Docker images.
There are several popular container registries available, including Docker Hub (the default public registry), Amazon Elastic Container Registry (ECR), Google Container Registry (GCR), and others. These registries provide a platform for users to publish their Docker images and make them available to others.
Organizations need to undertake due diligence when sourcing or managing Docker images. Application software can end up containing performance issues or security vulnerabilities if developers end up relying on images using outdated components. Whilst Docker makes it easy to package up something yourself to run, unless an organization is building all of their containers from source, they can become difficult to maintain.
An application and its services run in a Docker container. The Docker container is the result of a script contained in a Docker Image. Kubernetes can be used to build an orchestration platform that then allows containers to be operated and deployed. A platform built upon Kubernetes can orchestrate containers - move and scale them to maintain the desired state of the application and end service.
The application itself runs on a distributed system of cloud and physical servers, Kubernetes orchestration ensures that the resources are available and used optimally for the whole system, balancing and adjusting according to the needs of the applications running. In principle, this means with the right triggers and monitoring an application can respond to the demands on it. If demand surges, additional copies of a container can be spun up in seconds in geographies nearer to the demand. All of this relies on the infrastructure and tools within Kubernetes functioning correctly, so those looking to monitor Docker usually need to use a tool also capable of monitoring their orchestration platform and its dependencies.
Containers offer a practical way to build, test, deploy, and redeploy applications on multiple computing environments. The benefits of any container implementation include:
As one of the most widely adopted containerization technologies Docker offers users additional benefits. There is a strong ecosystem around Docker and it is relatively easy to access information, support and workers with Docker expertise.
An enterprise monitoring tool such as eG Enterprise designed to support Docker should provide you with comprehensive Docker monitoring without the need to interact with the Docker image or modify any run commands.
You should expect to be able to: