The <springProperty> tag allows you to surface properties from the Spring Environment for use within Logback. This can be useful if you want to access values from your application.properties file in your logback configuration.
どうやら springProperty を使うと良いらしい。多分こういうこと。
application.yml
my: log: prop: DEBUG
... <springProperty name="myLogProp" source="my.log.prop" /> <logger name="com.example.log"> <appender-ref ref="${myLogProp}" /> </logger> ...