Configure Multiple SonarQube Instances in a Gradle Build - gradle

Question

In our CI environment, we currently have one build server (based on Atlassian Bamboo) and two SonarQube instances (versions 6.0 and 6.5). Initially, our CI server was configured to communicate with the 6.0 SonarQube instance. This has been configured in the /home/bamboo/.gradle/gradle.properties file on our CI server like this:
systemProp.sonar.host.url=<http url of SonarQube 6.0 instance>
systemProp.sonar.login=<username here>
systemProp.sonar.password=<password here>
Now we have another Gradle-based project running on our CI server which shall talk to the new SonarQube 6.5 instance. I tried configuring this but failed all the time.
Things I have done so far:
Added commandline arguments to gradle wrapper command:
I have tried adding -Dsonar.host.url=, -Dsonar.login=, -Dsonar.password= to the Gradle command. As this didn't seem to work, I have also tried to set commandline arguments as SonarQube system properties using -DsystemProp.sonar.host.url=, -DsystemProp.sonar.login=, -DsystemProp.sonar.password=. This didn't work either.
Added properties to the build.gradle file
- Added properties to the build.gradle file like this:
sonarqube {
properties {
property "sonar.host.url", "<http url of SonarQube 6.0 instance>"
property "sonar.login", "<username here>"
property "sonar.password", "<password here>"
...<other SonarQube analysis settings here>...
}
}
In all cases, the CI server talked to the wrong SonarQube instance (6.0). My question is, whether it is possible to configure a single project to talk to another SonarQube instance. As you have seen, we use Gradle 3.2.1 as a build tool. And we are using the org.sonarqube Gradle plugin too.
Thank you for any help.
André

Answer 1

Your first try did not work, because you set the system properties from the commandline, but setting it from the project properties later on resets the system properties to the configured values.
Your second try did not work, because the systemProp.sonar.login syntax is only suppored in gradle.properties files, not via -P commandline project properties.
Your third try did not work because the SonarQube scanner prefers the system property values over the value configured via the DSL, so that one can change what is configured in the build script with the help of local configuration.
You need to set the system properties in your build script manually, this then overwrite what was automatically set from the project property. Using the project gradle.properties file does not work as the user file overwrite the project file. So you need something like System.properties.'sonar.login' = '...' in your build script. You can either hard-code it there, or then use project properties that you can set in your gradle.properties file or via -P parameters.
Besides that, I'd never depend on having any configuration in Gradle User dir on a build server. Most buildservers use build agents that might run on distributed machines, so you would always have to make sure that all build agents are configured the same and so on. I'd always configure in the build setup of the build server the according configuration, either by setting system properties, or environment properties or commandline arguments.
Just my 2ct.