How to perform a sonarqube analysis from drone io in github

Question

I am running sonar scans on github's pull requests from drone.io. This is the procedure I am following:

1. PR is made
2. Drone.io build is triggered
3. Gradle task is executed
4. Gradle's Sonar plugin with Drone's environment is run

The command I use in drone build:

gradle/wrapper all sonarqube \
 -Dsonar.analysis.mode=preview \
 -Dsonar.github.pullRequest=$DRONE_BUILD_NUMBER \
 -Dsonar.github.oauth=<github_token>

I am unable to find the PR ID in the drone environment. Is there any other way I can find it?

Answer 1

DRONE_PULL_REQUEST  env variable holds the pull request number(Check This). You can access all the environment variables through your build logs. You can do this by adding env command in your yaml file:

pipeline:
  build:
    image: golang
    commands:
      - env # dump environment variables

Your build logs after execution:

...
DRONE_PULL_REQUEST=42
DRONE_BUILD_EVENT=pull_request
...

Pull request is only set if drone is building a pull request hook.