Who can briefly introduce what docker is for?

1) test: Docker is very suitable for test release. Docker can be directly provided for testers to run after being packaged, and it is no longer necessary for testers to cooperate with operation and development to build and deploy the environment.

2) Test data separation: In the test, due to the change of test scenario, it is often necessary to modify the dependent database data or empty the cached data in changed memcache and Redis. Docker is lighter and more convenient than traditional virtual machines. These data can be easily separated into different images and switched at any time according to different needs.

3) Development: Developers * * * use the same Docker image, and the modified source code is mounted on the local disk. The program behavior is no longer different because of different environments, and the development and compilation environment can be quickly established when newcomers arrive at the post.

4)PaaS cloud service: Docker can support command line encapsulation and programming. Through automatic loading and service self-discovery, the services encapsulated in Docker image can be easily extended to cloud services. Services such as document conversion preview are encapsulated in the mirror image, and the number of containers can be increased or decreased at any time according to business requirements, and the number can be adjusted as needed.