什么是容器化？

In its simplest terms, containerization is bundling an application with all its necessary libraries, dependencies, and configuration files into a single entity called a container. That container is designed to run similarly in any environment, including a developer’s laptop and a cloud server, to minimize compatibility issues.

In contrast to virtual machines, which employ a separate guest operating system kernel, containers operate on the host’s kernel, allowing for a more lightweight and efficient approach.  To achieve higher overall throughput, several aspects, such as the fast startup time of the startup shell, utilization of the resources, and container density per host, should be improved.

Docker is an open-source platform commonly used to ensure the effective process of building, shipping, and running containers. The tool’s characteristics are to meet the challenges that arise when managing containers at stages of their life cycle.

Docker’s popularity can be attributed to several key features, such as:

• Image Creation: Docker makes it possible to build container image blueprints that set the framework for running containers. These images may be shared and created in one or several versions. 
• Container Runtime: Docker provides the implementational layer responsible for executing the containers and ensures their consistency of communication irrespective of the platform.
• 注册表： Docker Hub 是一个用于存储和共享容器镜像的中央存储库，以保证协作和重用。

容器化完全符合云原生应用程序的方法，该方法涉及创建和部署利用云提供的所有功能的应用程序。这些潜在的好处可能与几个具体的例子相关，包括：

• 可扩展性： 可以通过增加或减少容器的数量来管理容器，这可以利用工作负载并考虑成本控制。
•  可移植性： 容器化应用程序是可移植的，不受限于仅在一个云服务提供商环境中运行或与本地环境组合运行。
• 资源管理： 容器直接在端点的操作系统内核上运行，这使得它们能够比虚拟机托管更多的应用程序，但这反过来可能会影响资源利用率。

随着容器化应用程序的增长，它们开始变得复杂，并且很难通过手动流程进行管理。Kubernetes，一个 open-source 容器编排，开始发挥作用，以处理应用程序在运行时的部署、扩展和管理。此功能包括以下功能：

• Load Balancing: Kubernetes directs the incoming network traffic to several containers, leveraging containerization for improved efficiency and high availability.
• Self-Healing: Kubernetes restarts or replaces failed containers to ensure the application is always available.
• 服务发现： Kubernetes provides a mechanism for containers to locate each other and interact while considering scalability for managing their environment.

云原生开发中的容器化具有许多优点，但也存在一些缺点，如下所示： 

• 安全性： 需要有效地配置容器，以防止各种 云安全 与系统相关的威胁。开发人员应遵循一些安全最佳实践，包括镜像扫描和漏洞管理。
• 网络：  在复杂的网络中处理容器之间的交互只能通过指定的方式系统地进行。
• Storage:  It is very important to decide how to store a containerized application about performance, persistence, and data sharing.

Developers should consider appropriate security-oriented approaches, use compliant container networking systems, and choose efficient storage types depending on the application.