/**
* Returns the classloader that should be used as the parent classloader for all extensions. If
* the GUACAMOLE_HOME/lib directory exists, this will be a classloader that loads classes from
* within the .jar files in that directory. Lacking the GUACAMOLE_HOME/lib directory, this will
* simply be the classloader associated with the ExtensionModule class.
*
* @return The classloader that should be used as the parent classloader for all extensions.
* @throws GuacamoleException If an error occurs while retrieving the classloader.
*/
private ClassLoader getParentClassLoader() throws GuacamoleException {
// Retrieve lib directory
File libDir = new File(environment.getGuacamoleHome(), LIB_DIRECTORY);
// If lib directory does not exist, use default class loader
if (!libDir.isDirectory()) return ExtensionModule.class.getClassLoader();
// Return classloader which loads classes from all .jars within the lib directory
return DirectoryClassLoader.getInstance(libDir);
}
/**
* Loads all extensions within the GUACAMOLE_HOME/extensions directory, if any, adding their
* static resource to the given resoure collections.
*
* @param javaScriptResources A modifiable collection of static JavaScript resources which may
* receive new JavaScript resources from extensions.
* @param cssResources A modifiable collection of static CSS resources which may receive new CSS
* resources from extensions.
*/
private void loadExtensions(
Collection<Resource> javaScriptResources, Collection<Resource> cssResources) {
// Retrieve and validate extensions directory
File extensionsDir = new File(environment.getGuacamoleHome(), EXTENSIONS_DIRECTORY);
if (!extensionsDir.isDirectory()) return;
// Retrieve list of all extension files within extensions directory
File[] extensionFiles =
extensionsDir.listFiles(
new FileFilter() {
@Override
public boolean accept(File file) {
return file.isFile() && file.getName().endsWith(EXTENSION_SUFFIX);
}
});
// Verify contents are accessible
if (extensionFiles == null) {
logger.warn(
"Although GUACAMOLE_HOME/"
+ EXTENSIONS_DIRECTORY
+ " exists, its contents cannot be read.");
return;
}
// Sort files lexicographically
Arrays.sort(extensionFiles);
// Load each extension within the extension directory
for (File extensionFile : extensionFiles) {
logger.debug("Loading extension: \"{}\"", extensionFile.getName());
try {
// Load extension from file
Extension extension = new Extension(getParentClassLoader(), extensionFile);
// Validate Guacamole version of extension
if (!isCompatible(extension.getGuacamoleVersion())) {
logger.debug(
"Declared Guacamole version \"{}\" of extension \"{}\" is not compatible with this version of Guacamole.",
extension.getGuacamoleVersion(),
extensionFile.getName());
throw new GuacamoleServerException(
"Extension \""
+ extension.getName()
+ "\" is not "
+ "compatible with this version of Guacamole.");
}
// Add any JavaScript / CSS resources
javaScriptResources.addAll(extension.getJavaScriptResources().values());
cssResources.addAll(extension.getCSSResources().values());
// Attempt to load all authentication providers
bindAuthenticationProviders(extension.getAuthenticationProviderClasses());
// Add any translation resources
serveLanguageResources(extension.getTranslationResources());
// Add all HTML patch resources
patchResourceService.addPatchResources(extension.getHTMLResources().values());
// Add all static resources under namespace-derived prefix
String staticResourcePrefix = "/app/ext/" + extension.getNamespace() + "/";
serveStaticResources(staticResourcePrefix, extension.getStaticResources());
// Serve up the small favicon if provided
if (extension.getSmallIcon() != null)
serve("/images/logo-64.png").with(new ResourceServlet(extension.getSmallIcon()));
// Serve up the large favicon if provided
if (extension.getLargeIcon() != null)
serve("/images/logo-144.png").with(new ResourceServlet(extension.getLargeIcon()));
// Log successful loading of extension by name
logger.info("Extension \"{}\" loaded.", extension.getName());
} catch (GuacamoleException e) {
logger.error(
"Extension \"{}\" could not be loaded: {}", extensionFile.getName(), e.getMessage());
logger.debug("Unable to load extension.", e);
}
}
}