GUAC-587: Define class representing extensions and the extension manifest file. Dynamically add JavaScript and CSS resources to app.js and app.css.

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/extension/Extension.java

@@ -0,0 +1,241 @@
+/*
+ * Copyright (C) 2015 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package org.glyptodon.guacamole.net.basic.extension;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.security.AccessController;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipException;
+import java.util.zip.ZipFile;
+import org.codehaus.jackson.JsonParseException;
+import org.codehaus.jackson.map.ObjectMapper;
+import org.glyptodon.guacamole.GuacamoleException;
+import org.glyptodon.guacamole.GuacamoleServerException;
+import org.glyptodon.guacamole.net.basic.resource.ClassPathResource;
+import org.glyptodon.guacamole.net.basic.resource.Resource;
+
+/**
+ * A Guacamole extension, which may provide custom authentication, static
+ * files, theming/branding, etc.
+ *
+ * @author Michael Jumper
+ */
+public class Extension {
+
+    /**
+     * The Jackson parser for parsing the language JSON files.
+     */
+    private static final ObjectMapper mapper = new ObjectMapper();
+
+    /**
+     * The name of the manifest file that describes the contents of a
+     * Guacamole extension.
+     */
+    private static final String MANIFEST_NAME = "guac-manifest.json";
+
+    /**
+     * The parsed manifest file of this extension, describing the location of
+     * resources within the extension.
+     */
+    private final ExtensionManifest manifest;
+
+    /**
+     * The classloader to use when reading resources from this extension,
+     * including classes and static files.
+     */
+    private final ClassLoader classLoader;
+
+    /**
+     * Loads the given file as an extension, which must be a .jar containing
+     * a guac-manifest.json file describing its contents.
+     *
+     * @param parent
+     *     The classloader to use as the parent for the isolated classloader of
+     *     this extension.
+     *
+     * @param file
+     *     The file to load as an extension.
+     *
+     * @throws GuacamoleException
+     *     If the provided file is not a .jar file, does not contain the
+     *     guac-manifest.json, or if guac-manifest.json is invalid and cannot
+     *     be parsed.
+     */
+    public Extension(final ClassLoader parent, final File file) throws GuacamoleException {
+
+        try {
+
+            // Open extension
+            ZipFile extension = new ZipFile(file);
+
+            try {
+
+                // Retrieve extension manifest
+                ZipEntry manifestEntry = extension.getEntry(MANIFEST_NAME);
+                if (manifestEntry == null)
+                    throw new GuacamoleServerException("Extension " + file.getName() + " is missing " + MANIFEST_NAME);
+
+                // Parse manifest
+                manifest = mapper.readValue(extension.getInputStream(manifestEntry), ExtensionManifest.class);
+
+            }
+
+            // Always close zip file, if possible
+            finally {
+                extension.close();
+            }
+
+            try {
+
+                // Create isolated classloader for this extension
+                classLoader = AccessController.doPrivileged(new PrivilegedExceptionAction<ClassLoader>() {
+
+                    @Override
+                    public ClassLoader run() throws GuacamoleException {
+
+                        try {
+
+                            // Classloader must contain only the extension itself
+                            return new URLClassLoader(new URL[]{file.toURI().toURL()}, parent);
+
+                        }
+                        catch (MalformedURLException e) {
+                            throw new GuacamoleException(e);
+                        }
+
+                    }
+
+                });
+
+            }
+
+            // Rethrow any GuacamoleException
+            catch (PrivilegedActionException e) {
+                throw (GuacamoleException) e.getException();
+            }
+
+        }
+
+        // Abort load if not a valid zip file
+        catch (ZipException e) {
+            throw new GuacamoleServerException("Extension is not a valid zip file: " + file.getName(), e);
+        }
+
+        // Abort if manifest cannot be parsed (invalid JSON)
+        catch (JsonParseException e) {
+            throw new GuacamoleServerException(MANIFEST_NAME + " is not valid JSON: " + file.getName(), e);
+        }
+
+        // Abort if zip file cannot be read at all due to I/O errors
+        catch (IOException e) {
+            throw new GuacamoleServerException("Unable to read extension: " + file.getName(), e);
+        }
+
+    }
+
+    /**
+     * Returns the name of this extension, as declared in the extension's
+     * manifest.
+     *
+     * @return
+     *     The name of this extension.
+     */
+    public String getName() {
+        return manifest.getName();
+    }
+
+    /**
+     * Returns the namespace of this extension, as declared in the extension's
+     * manifest.
+     *
+     * @return
+     *     The namespace of this extension.
+     */
+    public String getNamespace() {
+        return manifest.getNamespace();
+    }
+
+    /**
+     * Returns a new collection of resources corresponding to the collection of
+     * paths provided. Each resource will be associated with the given
+     * mimetype.
+     *
+     * @param mimetype
+     *     The mimetype to associate with each resource.
+     *
+     * @param paths
+     *     The paths corresponding to the resources desired.
+     *
+     * @return
+     *     A new, unmodifiable collection of resources corresponding to the
+     *     collection of paths provided.
+     */
+    private Collection<Resource> getClassPathResources(String mimetype, Collection<String> paths) {
+
+        // If no paths are provided, just return an empty list
+        if (paths == null)
+            return Collections.<Resource>emptyList();
+
+        // Add classpath resource for each path provided
+        Collection<Resource> resources = new ArrayList<Resource>(paths.size());
+        for (String path : paths)
+            resources.add(new ClassPathResource(classLoader, mimetype, path));
+
+        // Callers should not rely on modifying the result
+        return Collections.unmodifiableCollection(resources);
+
+    }
+
+    /**
+     * Returns all declared JavaScript resources associated with this
+     * extension. JavaScript resources are declared within the extension
+     * manifest.
+     *
+     * @return
+     *     All declared JavaScript resources associated with this extension.
+     */
+    public Collection<Resource> getJavaScriptResources() {
+        return getClassPathResources("text/javascript", manifest.getJavaScriptPaths());
+    }
+
+    /**
+     * Returns all declared CSS resources associated with this extension. CSS
+     * resources are declared within the extension manifest.
+     *
+     * @return
+     *     All declared CSS resources associated with this extension.
+     */
+    public Collection<Resource> getCSSResources() {
+        return getClassPathResources("text/css", manifest.getCSSPaths());
+    }
+
+}

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/extension/ExtensionManifest.java

@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2015 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package org.glyptodon.guacamole.net.basic.extension;
+
+import java.util.Collection;
+import org.codehaus.jackson.annotate.JsonProperty;
+
+/**
+ * Java representation of the JSON manifest contained within every Guacamole
+ * extension, identifying an extension and describing its contents.
+ *
+ * @author Michael Jumper
+ */
+public class ExtensionManifest {
+
+    /**
+     * The name of the extension associated with this manifest. The extension
+     * name is human-readable, and used for display purposes only.
+     */
+    private String name;
+
+    /**
+     * The namespace of the extension associated with this manifest. The
+     * extension namespace is required for internal use, and is used wherever
+     * extension-specific files or resources need to be isolated from those of
+     * other extensions.
+     */
+    private String namespace;
+
+    /**
+     * The paths of all JavaScript resources within the .jar of the extension
+     * associated with this manifest.
+     */
+    private Collection<String> javaScriptPaths;
+
+    /**
+     * The paths of all CSS resources within the .jar of the extension
+     * associated with this manifest.
+     */
+    private Collection<String> cssPaths;
+
+    /**
+     * Returns the name of the extension associated with this manifest. The
+     * name is human-readable, for display purposes only, and is defined within
+     * the manifest by the "name" property.
+     *
+     * @return
+     *     The name of the extension associated with this manifest.
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Sets the name of the extension associated with this manifest. The name
+     * is human-readable, for display purposes only, and is defined within the
+     * manifest by the "name" property.
+     *
+     * @param name
+     *     The name of the extension associated with this manifest.
+     */
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    /**
+     * Returns the namespace of the extension associated with this manifest.
+     * The namespace is required for internal use, and is used wherever
+     * extension-specific files or resources need to be isolated from those of
+     * other extensions. It is defined within the manifest by the "namespace"
+     * property.
+     *
+     * @return
+     *     The namespace of the extension associated with this manifest.
+     */
+    public String getNamespace() {
+        return namespace;
+    }
+
+    /**
+     * Sets the namespace of the extension associated with this manifest. The
+     * namespace is required for internal use, and is used wherever extension-
+     * specific files or resources need to be isolated from those of other
+     * extensions. It is defined within the manifest by the "namespace"
+     * property.
+     *
+     * @param namespace
+     *     The namespace of the extension associated with this manifest.
+     */
+    public void setNamespace(String namespace) {
+        this.namespace = namespace;
+    }
+
+    /**
+     * Returns the paths to all JavaScript resources within the extension.
+     * These paths are defined within the manifest by the "js" property as an
+     * array of strings, where each string is a path relative to the root of
+     * the extension .jar.
+     *
+     * @return
+     *     A collection of paths to all JavaScript resources within the
+     *     extension.
+     */
+    @JsonProperty("js")
+    public Collection<String> getJavaScriptPaths() {
+        return javaScriptPaths;
+    }
+
+    /**
+     * Sets the paths to all JavaScript resources within the extension. These
+     * paths are defined within the manifest by the "js" property as an array
+     * of strings, where each string is a path relative to the root of the
+     * extension .jar.
+     *
+     * @param javaScriptPaths
+     *     A collection of paths to all JavaScript resources within the
+     *     extension.
+     */
+    @JsonProperty("js")
+    public void setJavaScriptPaths(Collection<String> javaScriptPaths) {
+        this.javaScriptPaths = javaScriptPaths;
+    }
+
+    /**
+     * Returns the paths to all CSS resources within the extension. These paths
+     * are defined within the manifest by the "js" property as an array of
+     * strings, where each string is a path relative to the root of the
+     * extension .jar.
+     *
+     * @return
+     *     A collection of paths to all CSS resources within the extension.
+     */
+    @JsonProperty("css")
+    public Collection<String> getCSSPaths() {
+        return cssPaths;
+    }
+
+    /**
+     * Sets the paths to all CSS resources within the extension. These paths
+     * are defined within the manifest by the "js" property as an array of
+     * strings, where each string is a path relative to the root of the
+     * extension .jar.
+     *
+     * @param cssPaths
+     *     A collection of paths to all CSS resources within the extension.
+     */
+    @JsonProperty("css")
+    public void setCSSPaths(Collection<String> cssPaths) {
+        this.cssPaths = cssPaths;
+    }
+
+}

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/extension/ExtensionModule.java

@@ -25,8 +25,13 @@ package org.glyptodon.guacamole.net.basic.extension;
 import com.google.inject.servlet.ServletModule;
 import java.io.File;
 import java.io.FileFilter;
+import java.util.ArrayList;
+import java.util.Collection;
+import org.glyptodon.guacamole.GuacamoleException;
 import org.glyptodon.guacamole.environment.Environment;
+import org.glyptodon.guacamole.net.basic.resource.Resource;
 import org.glyptodon.guacamole.net.basic.resource.ResourceServlet;
+import org.glyptodon.guacamole.net.basic.resource.SequenceResource;
 import org.glyptodon.guacamole.net.basic.resource.WebApplicationResource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -55,7 +60,7 @@ public class ExtensionModule extends ServletModule {
      * recognized as extensions.
      */
     private static final String EXTENSION_SUFFIX = ".jar";
-    
+
     /**
      * The Guacamole server environment.
      */
@@ -81,7 +86,7 @@ public class ExtensionModule extends ServletModule {
             return;
 
         // Retrieve list of all extension files within extensions directory
-        File[] extensions = extensionsDir.listFiles(new FileFilter() {
+        File[] extensionFiles = extensionsDir.listFiles(new FileFilter() {
 
             @Override
             public boolean accept(File file) {
@@ -90,15 +95,43 @@ public class ExtensionModule extends ServletModule {
 
         });
 
-        // Load each extension
+        // Init JavaScript resources with base guacamole.min.js
-        for (File extension : extensions) {
+        Collection<Resource> javaScriptResources = new ArrayList<Resource>();
-            // TODO: Actually load extension
+        javaScriptResources.add(new WebApplicationResource(getServletContext(), "/guacamole.min.js"));
-            logger.info("Loading extension: \"{}\"", extension.getName());
+
+        // Init CSS resources with base guacamole.min.css
+        Collection<Resource> cssResources = new ArrayList<Resource>();
+        cssResources.add(new WebApplicationResource(getServletContext(), "/guacamole.min.css"));
+
+        // Load each extension within the extension directory
+        for (File extensionFile : extensionFiles) {
+
+            logger.debug("Loading extension: \"{}\"", extensionFile.getName());
+
+            try {
+
+                // FIXME: Use class loader which reads from the lib directory
+                // Load extension from file
+                Extension extension = new Extension(ExtensionModule.class.getClassLoader(), extensionFile);
+
+                // Add any JavaScript / CSS resources
+                javaScriptResources.addAll(extension.getJavaScriptResources());
+                cssResources.addAll(extension.getCSSResources());
+
+                // 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);
+            }
+
         }
-        
+
-        // TODO: Pull these from extensions, dynamically concatenated
+        // Dynamically generate app.js and app.css from extensions
-        serve("/app.js").with(new ResourceServlet(new WebApplicationResource(getServletContext(), "/guacamole.min.js")));
+        serve("/app.js").with(new ResourceServlet(new SequenceResource(javaScriptResources)));
-        serve("/app.css").with(new ResourceServlet(new WebApplicationResource(getServletContext(), "/guacamole.min.css")));
+        serve("/app.css").with(new ResourceServlet(new SequenceResource(cssResources)));
 
     }