As reported in SUPPORT-4979 we have an issue that the file-based resource loader currently loads a lot of stuff we don't want it to like our 'mgnl-bootstrap' folder. We really need the list of excluded directories to be made configurable.

The issue is in the FileSystemResourceOrigin class where the list of excluded directories is currently hardcoded:

   /**
     * TODO: The current implementation makes assumptions about what directories to excludes;
     * Except for META-INF and WEB-INF, the others are highly installation dependent. We could probably use system properties
     * and/or make this configurable.
     */
    protected ExclusionsFilter buildExclusionsFilter() {
        return new ExclusionsFilter(rootPath, EXCLUDED_DIRECTORIES, Collections.<String>emptyList(), Collections.<String>emptyList());
    }

Solution

Decided to expose this directories in properties file with name:
magnolia.resources.filesystem.observation.excludedDirectories

It is commented by default and once one uncomments it, we would expect to have a present value in it for activating that property.
Also It should be known that, this property values are trimmed which means that having a exclusion value with path ' bar ',
will be filtering bar folder