Support for configuration backwards compatibility
See Configuration versioning for details on configuration versioning support by the framework.
When declaring ApplicationDetails via the getApplicationDetails()
method in Gateway Application, application developers will have to define the version of supported application defined configuration. If the application configuration
changes in future with breaking changes, it’s the responsibility of the
developers to ensure that they provide necessary functions which will
convert the older version of application configuration to the latest
expected version.
The framework provides additional builder methods in
newApplicationDetailsBuilder to define such configuration upgrading
functions, for global configs, sharedConfigs and services. By default, a
function which returns the same older version of configuration is used,
if no functions are explicitly specified. See Gateway Framework API Javadoc for more details.
A Gateway application must specify the version of application configuration it supports and the version of framework expected framework configuration version, in its user guide or documentation, so that the users can use these version numbers in the configuration they create.