This is a forked Docker image from the official Docker image for SonarQube. See the Hub page for the full readme on how to use the Docker image and for information regarding contributing and issues.
The full readme is generated over in docker-library/docs, specifically in docker-library/docs/sonarqube.
The only difference from original one is I put volumn on $SONARQUBE_HOME/conf for put customized sonar.properties for your needs, for example, connect to your LDAP service.