Do not compile wsrep_provider plugin if WITH_WSREP is not enabled.
We should not enable wsrep_provider plugin if WSREP_ON=OFF and
at that case we can only print information that Plugin
'wsrep-provider' is disabled.
Make sure tests require Galera library 26.4.14 if needed.
- Provider options are read from the provider during
startup, before plugins are initialized.
- New wsrep_provider plugin for which sysvars are generated
dynamically from options read from the provider.
- The plugin is enabled by option plugin-wsrep-provider=ON.
If enabled, wsrep_provider_options can no longer be used,
(an error is raised on attempts to do so).
- Each option is either string, integer, double or bool
- Options can be dynamic / readonly
- Options can be deprecated
Limitations:
- We do not check that the value of a provider option falls
within a certain range. This type of validation is still
done in Galera side.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
