It's really great to do CI/CD based on drone. Compared with jekins, the big brother in the industry, I prefer drone. In comparison, I think it has the following advantages

1. Plug in does not require additional management
2. Based on yaml file, easy to write, configuration can be version management
3. Can be built according to different conditions
4. More user-friendly UI interface

For our back-end java projects, what do we CI do?

As can be seen from the above figure, when we submit the code, the entire CI process will be executed. The following two points need to be noted

1. When executing build or unit test, if it fails, it will send a message to Slack. At this time, developers can notice this problem. Of course, they can also send email or wechat
2. When executing SonarQube check, if there is a problem, the result will be written back to github, and the developers will look at the problem

First, let's look at the results of the check that SonarQube wrote back to github

When the sonar qube detection is completed, the results will be sent to github through oauth, so you need to create a personal access token in github (this should be noted down)

kind: pipeline
name: default

steps:
# build for push and pull_request
- name: build-pr
  image: maven:latest
  pull: if-not-exists
  commands:
  - mvn clean org.jacoco:jacoco-maven-plugin:prepare-agent install -Dmaven.test.skip=true -s settings.xml
  when:
    branch:
    - feature/*
    - issue/*
    - develop
    event:
    - push
    - pull_request

- name: unittest
  image: maven:latest
  pull: if-not-exists
  commands:
  - mvn test -s settings.xml
  when:
    branch:
    - develop
    event:
      include:
      - pull_request
      - push

# Here we use the command to customize our scan in depth, rather than using the drone sonar plugin
- name: sonar-scan
  image: newtmitch/sonar-scanner:4.0.0-alpine
  environment:
    SONAR_TOKEN:
      from_secret: sonar_token
    GITHUB_ACCESS_TOKEN_FOR_SONARQUBE:
      from_secret: github_access_token_for_sonarqube
  commands:
  - >
    sonar-scanner
    -Dsonar.host.url=https://sonarqube.company-beta.com/
    -Dsonar.login=$$SONAR_TOKEN
    -Dsonar.projectKey=smcp-service-BE
    -Dsonar.projectName=smcp-service-BE
    -Dsonar.projectVersion=${DRONE_BUILD_NUMBER}
    -Dsonar.sources=src/main/java
    -Dsonar.tests=src/test/java
    -Dsonar.language=java
    -Dsonar.java.coveragePlugin=jacoco
    -Dsonar.modules=smcp-api,smcp-web
    -Dsonar.java.binaries=target
    -Dsonar.projectBaseDir=.
    -Dsonar.analysis.mode=preview
    -Dsonar.github.repository=Today_Group/SMCP-Service
    -Dsonar.github.oauth=$$GITHUB_ACCESS_TOKEN_FOR_SONARQUBE
    -Dsonar.github.pullRequest=${DRONE_PULL_REQUEST}
    -Dsonar.github.disableInlineComments=false
  when:
    event:
    - pull_request
    branch:
    - develop

# post sonarscan result back to git PR (not in preview mode)
- name: sonar-scan-feedback
  image: newtmitch/sonar-scanner:4.0.0-alpine
  environment:
    SONAR_TOKEN:
      from_secret: sonar_token
    GITHUB_ACCESS_TOKEN_FOR_SONARQUBE:
      from_secret: github_access_token_for_sonarqube
  commands:
    - >
      sonar-scanner
      -Dsonar.host.url=https://sonarqube.company-beta.com/
      -Dsonar.login=$$SONAR_TOKEN
      -Dsonar.projectKey=smcp-service-BE
      -Dsonar.projectName=smcp-service-BE
      -Dsonar.projectVersion=${DRONE_BUILD_NUMBER}
      -Dsonar.sources=src/main/java
      -Dsonar.tests=src/test/java
      -Dsonar.language=java
      -Dsonar.java.coveragePlugin=jacoco
      -Dsonar.modules=smcp-api,smcp-web
      -Dsonar.java.binaries=target
      -Dsonar.projectBaseDir=.
      -Dsonar.analysis.gitRepo=Today_Group/SMCP-Service
      -Dsonar.analysis.pullRequest=${DRONE_PULL_REQUEST}
  when:
    event:
      - pull_request
    branch:
      - develop

The above configuration of drone is the basic process of the whole CI, which should be noted as follows

1. The above steps are triggered only when the branch name starts with feature /, issue /, and development. For unit test, only the development branch takes effect (you can customize it according to your needs)
2. The sonar.projectkey and the sonar.projectname in the sonar configuration must be the same as the name when you create a project in the sonar server (the address specified by sonar.host.url)
3. The value of sonar_token is created on the sonar server, and then it is set in the secrets of drone (click a warehouse in drone and enter Settings to set it)
4. github token and sonar'u token are the same way, they need to be preset in drone (the advantage is that you will not expose your password in the file, which is more secure)
5. Because the Java project is a multi module project, you can specify multiple module names in sonar.modules
6. Don't specify preview mode when the content of sonar scan feedback goes to pr
7. Jacoco (analysis unit test coverage) is used in build ing, so this plugin needs to be introduced into pom.xml in java project

<plugin>
  <groupId>org.jacoco</groupId>
  <artifactId>jacoco-maven-plugin</artifactId>
  <version>${jacoco.version}</version>
  <executions>
    <execution>
      <id>prepare-agent</id>
      <goals>
          <goal>prepare-agent</goal>
      </goals>
    </execution>
    <execution>
      <id>default-report</id>
      <phase>test</phase>
      <goals>
          <goal>report</goal>
      </goals>
      <configuration>
          <dataFile>target/jacoco.exec</dataFile>
          <outputDirectory>target/jacoco</outputDirectory>
      </configuration>
    </execution>
  </executions>
</plugin>

Other possible problems:

1. How to send email or message to wechat group after ci execution

A: drone provided information about mail and Wechat plug in

1. Can sonarqube integrate Alibaba's p3c or custom checkstyle

A: there is no p3c plug-in, but it can be integrated through PMD

1. What should I do according to the information of build (success, time, etc.)?

A: drone provides a plugin for webhook. You only need to write your own statistical program. You can set the information you need to send according to the template settings

1. What can I do without the plug-in I want?

A: you can write a plug-in by yourself. There are bash/go examples on the official website. You can also use a familiar language

Don't get lost