Each property listed in the file conf/sonar.properties should be overridable from an environment variable. This behavior is required for a proper support of Docker runtimes.
The naming conversion is strict. Any letter of the property are upper-cased and any special character like dot or dash is replaced by an underscore. For instance the property sonar.foo.barBaz can be set through the env variable SONAR_FOO_BARBAZ.
Env variables take precedence.
No need for disabling the support of env variables on non-Docker runtimes.
The feature and the newly env variables should be documented. The file conf/sonar.properties should only mention the feature. No need to describe each variable.