External Spring boot configuration does not override internal ones

[ascheman]

If a configuration property, in particular conferences.file, is specified internally and externally (cf. https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html) both values are used. Unfortunately the internal one beats the external one in this case.

Given the following scenario:

• The bundled application.properties file contains the property with value conferences.file=conferences-dev.yml, and

• there is an external file /opt/dukecon/config/application.properties with value conferences.file=/opt/dukecon/config/conferences.yml,

• and /opt/dukecon/config specified as Spring config location (e.g. --spring.config.location=/opt/dukecon/config).

Now the application behaves the following way:

• It first reads the externally specified /opt/dukecon/config/conferences.yml and initializes the conference list with the data,
• Then it again initializes the conferences list with the data from the internally specified conferences-dev.yml.

Finally only the conferences from the latter file are contained in the application.