Continuous integration, continuous delivery and continuous deployment (ci/cd) details

CI/CD Detailed introduction

The general process of a complete system ： The product design -> Developers develop code -> The tester tests the function -> Operation and maintenance personnel released online .

One 、 Integrate （Integration）

In actual software development , There are often the following two scenarios ：

1. Now there is an e-commerce platform to be developed , Due to the large number of e-commerce platform modules , At this point, different developers are required to develop different modules , Finally, integrate all the developed code into one system , After integration, it needs to be deployed online .

2. as time goes on , Whether the system is bug Repair 、 Or new function development , In the future, the system needs to be updated and iterated continuously .

in general ： Integration is that all developers combine their own modules to form a complete system .

Two 、 Continuous integration （Continuous Integration）

Continuous integration refers to the frequent integration of code into the backbone （ Repeat the above integration work ）, Here's the picture ：

After the developer submits the new code , Build immediately and automatically , Perform unit tests （ Can pass Jenkins complete ）, Developers only need to submit code , You can get the result of this integration , Based on the results , It can be determined whether the new code and the original code can be correctly integrated .

Benefits of using continuous integration ：

1. Find mistakes quickly , Every time I finish a little update , It's integrated into the backbone , You can quickly find mistakes , It's also easier to get a location error .

2. Save labor costs , adopt Jenkins Automated build .

3. Speed up software development .

4. Real time delivery .

The core of continuous integration ：

Before the code is integrated into the trunk , Start with automated testing . As long as one test case fails , You can't integrate , Of course, continuous integration cannot completely eliminate Bug, It's about making them easy to find and correct .

3、 ... and 、 Continuous delivery （Continuous Delivery）

Continuous delivery is based on continuous integration , Automatically deploy code to a pre production environment （Staging）, Here's the picture ：

Staging The environment can be understood as a mirror image of the online environment （ Simulate the online environment to the greatest extent ）, Testers 、PM In a pre production environment （Staging） Make the final round of verification on the final project to be deployed .

If the pre production environment is verified , need Manual Deploy online （ production ） Environmental Science .

Four 、 Continuous deployment （Continuous Deployment）

Continuous deployment is the next step in continuous delivery , It means that the code Automatically Deploy to production , Here's the picture ：

The difference between continuous delivery and continuous deployment is whether the final deployment to the production environment is automatic .

Development only needs to submit code , Don't do anything else , If the code passes the test , It can be fully automatically deployed to the production environment .