Introduction to Docker
Docker is an open source application container engine, based on the Go language and open source following the Apache 2.0 protocol.
Docker allows developers to package their applications and dependent packages into a lightweight, portable container, and then publish it to any popular Linux machine, which can also be virtualized.
Containers use the sandbox mechanism completely, and there will not be any interfaces between each other, and more importantly, the container performance overhead is extremely low.
Docker has been divided into CE (Community Edition: Community Edition) and EE (Enterprise Edition: Enterprise Edition) since version 17.03. We can use the Community Edition.
There are currently three main uses of Docker.
(1) Provide a one-time environment. For example, local testing of other people's software, continuous integration to provide unit testing and construction environment.
(2) Provide flexible cloud services. Because Docker containers can be opened and closed at any time, it is very suitable for dynamic expansion and shrinkage.
(3) Establish a microservice architecture. Through multiple containers, one machine can run multiple services, so the microservice architecture can be simulated on the local machine.
Docker application scenarios
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Automated packaging and publishing of Web applications.
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Automated testing and continuous integration and release.
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Deploy and adjust databases or other background applications in a service-oriented environment.
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Compile or extend the existing OpenShift or Cloud Foundry platform from scratch to build your own PaaS environment. (PaaS is the abbreviation of (Platform as a Service), which refers to the platform as a service. The server platform is a business model for providing services, and the services provided by programs through the network are called SaaS (Software as a Service), while the cloud The corresponding server platform or development environment provided as a service in the computing era becomes PaaS (Platform as a Service).)
Advantages of Docker
Docker is an open platform for developing, delivering and running applications. Docker enables you to separate your application from the infrastructure so you can deliver software quickly. With Docker, you can manage your infrastructure in the same way you manage applications. By using Docker's method to quickly deliver, test, and deploy code, you can greatly reduce the delay between writing code and running it in a production environment.
1. Deliver your application quickly and consistently
Docker allows developers to use the local containers of the applications or services you provide to work in a standardized environment, thus simplifying the development life cycle.
Containers are very suitable for continuous integration and continuous delivery (CI/CD) workflows. Please consider the following example scenarios:
- Your developers write code locally and use Docker containers to share their work with colleagues.
- They use Docker to push their applications into the test environment and perform automated or manual testing.
- When developers find a bug, they can fix it in the development environment, and then redeploy it to the test environment for testing and verification.
- After the test is completed, pushing the patch to the production environment is as simple as pushing the updated image to the production environment.
2. Responsive deployment and expansion
Docker is a container-based platform that allows highly portable workloads. Docker containers can run on the developer's native machine, on a physical or virtual machine in the data center, on a cloud service, or in a hybrid environment.
Docker's portability and lightweight features can also enable you to easily complete the workload of dynamic management, and according to business needs instructions, real-time expansion or removal of applications and services.
3. Run more workloads on the same hardware
Docker is light and fast. It provides a feasible, economical, and efficient alternative to virtual machines based on hypervisors, so you can use more computing power to achieve business goals. Docker is very suitable for high-density environments and small and medium deployments, and you can do more with fewer resources.
To make a little progress every day, it is inevitable to embrace happiness.
Make a little progress every day and you can see the growth footprint.