GUACAMOLE-641: Leverage singleton instance of LocalEnvironment.

This commit is contained in:
Michael Jumper
2020-08-25 16:01:13 -07:00
parent 30ddd7a092
commit fc7c7b7966
3 changed files with 74 additions and 479 deletions

View File

@@ -26,12 +26,13 @@ import java.io.FilenameFilter;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.CopyOnWriteArrayList;
import org.apache.guacamole.GuacamoleException;
import org.apache.guacamole.GuacamoleServerException;
import org.apache.guacamole.net.auth.GuacamoleProxyConfiguration;
import org.apache.guacamole.properties.BooleanGuacamoleProperty;
import org.apache.guacamole.properties.GuacamoleProperties;
import org.apache.guacamole.properties.GuacamoleProperty;
import org.apache.guacamole.protocols.ProtocolInfo;
import org.slf4j.Logger;
@@ -40,7 +41,10 @@ import org.slf4j.LoggerFactory;
/**
* The environment of the locally-running Guacamole instance, describing
* available protocols, configuration parameters, and the GUACAMOLE_HOME
* directory.
* directory. Sources of configuration properties like guacamole.properties and
* environment variables will be automatically added by the Guacamole web
* application and may also be added by extensions using
* {@link #addGuacamoleProperties(org.apache.guacamole.properties.GuacamoleProperties)}.
*/
public class LocalEnvironment implements Environment {
@@ -52,8 +56,13 @@ public class LocalEnvironment implements Environment {
/**
* Array of all known protocol names.
*/
private static final String[] KNOWN_PROTOCOLS = new String[]{
"vnc", "rdp", "ssh", "telnet", "kubernetes"};
private static final String[] KNOWN_PROTOCOLS = new String[] {
"kubernetes",
"rdp",
"ssh",
"telnet",
"vnc",
};
/**
* The hostname to use when connecting to guacd if no hostname is provided
@@ -73,23 +82,6 @@ public class LocalEnvironment implements Environment {
*/
private static final boolean DEFAULT_GUACD_SSL = false;
/**
* A property that determines whether environment variables are evaluated
* to override properties specified in guacamole.properties.
*/
private static final BooleanGuacamoleProperty ENABLE_ENVIRONMENT_PROPERTIES =
new BooleanGuacamoleProperty() {
@Override
public String getName() {
return "enable-environment-properties";
}
};
/**
* All properties read from guacamole.properties.
*/
private final Properties properties;
/**
* The location of GUACAMOLE_HOME, which may not truly exist.
*/
@@ -101,9 +93,13 @@ public class LocalEnvironment implements Environment {
private final Map<String, ProtocolInfo> availableProtocols;
/**
* Flag indicating whether environment variables can override properties.
* All GuacamoleProperties instances added via addGuacamoleProperties(), in
* the order that they were added. This storage has been made static to
* allow addGuacamoleProperties() to work as expected even if extensions
* continue to use the deprecated constructor to create non-singleton
* instances.
*/
private final boolean environmentPropertiesEnabled;
private static final List<GuacamoleProperties> availableProperties = new CopyOnWriteArrayList<>();
/**
* The Jackson parser for parsing JSON files.
@@ -111,56 +107,43 @@ public class LocalEnvironment implements Environment {
private static final ObjectMapper mapper = new ObjectMapper();
/**
* Creates a new Environment, initializing that environment based on the
* location of GUACAMOLE_HOME and the contents of guacamole.properties.
*
* @throws GuacamoleException If an error occurs while determining the
* environment of this Guacamole instance.
* Singleton instance of this environment, to be returned by calls to
* getInstance().
*/
public LocalEnvironment() throws GuacamoleException {
private static final LocalEnvironment instance = new LocalEnvironment();
/**
* Returns a singleton instance of LocalEnvironment which may be shared by
* the Guacamole web application and all extensions.
*
* @return
* A singleton instance of this class.
*/
public static LocalEnvironment getInstance() {
return instance;
}
/**
* Creates a new LocalEnvironment, initializing that environment based on
* the contents of GUACAMOLE_HOME. Sources of configuration properties like
* guacamole.properties and environment variables will be automatically
* added by the Guacamole web application and/or any installed extensions.
*
* @deprecated
* Extensions leveraging LocalEnvironment should instead use
* LocalEnvironment.getInstance() to obtain a singleton instance of the
* environment.
*/
@Deprecated
public LocalEnvironment() {
// Determine location of GUACAMOLE_HOME
guacHome = findGuacamoleHome();
logger.info("GUACAMOLE_HOME is \"{}\".", guacHome.getAbsolutePath());
// Read properties
properties = new Properties();
try {
InputStream stream = null;
// If not a directory, load from classpath
if (!guacHome.isDirectory())
stream = LocalEnvironment.class.getResourceAsStream("/guacamole.properties");
// Otherwise, try to load from file
else {
File propertiesFile = new File(guacHome, "guacamole.properties");
if (propertiesFile.exists())
stream = new FileInputStream(propertiesFile);
}
// Load properties from stream, if any, always closing stream when done
if (stream != null) {
try { properties.load(stream); }
finally { stream.close(); }
}
// Notify if we're proceeding without guacamole.properties
else
logger.info("No guacamole.properties file found within GUACAMOLE_HOME or the classpath. Using defaults.");
}
catch (IOException e) {
logger.warn("The guacamole.properties file within GUACAMOLE_HOME cannot be read: {}", e.getMessage());
logger.debug("Error reading guacamole.properties.", e);
}
// Read all protocols
availableProtocols = readProtocols();
// Should environment variables override configuration properties?
environmentPropertiesEnabled = environmentPropertiesEnabled(properties);
}
/**
@@ -265,7 +248,7 @@ public class LocalEnvironment implements Environment {
logger.error("Unable to read contents of \"{}\".", protocol_directory.getAbsolutePath());
files = new File[0];
}
// Load each protocol from each file
for (File file : files) {
@@ -319,69 +302,39 @@ public class LocalEnvironment implements Environment {
}
/**
* Checks for the presence of the {@link #ENABLE_ENVIRONMENT_PROPERTIES}
* property in the given properties collection.
*
* @param properties
* The properties collection to check.
*
* @return
* true if the property is present in the given properties collection
* and its parsed value is true
*
* @throws GuacamoleException If the value specified for the property
* cannot be successfully parsed as a Boolean
*
*/
private static boolean environmentPropertiesEnabled(Properties properties)
throws GuacamoleException {
final Boolean enabled = ENABLE_ENVIRONMENT_PROPERTIES.parseValue(
properties.getProperty(ENABLE_ENVIRONMENT_PROPERTIES.getName()));
return enabled != null && enabled;
}
@Override
public File getGuacamoleHome() {
return guacHome;
}
/**
* Gets the string value for a property name.
*
* The value may come from either the OS environment (if property override
* is enabled) or the Properties collection that was loaded from
* guacamole.properties. When checking the environment for the named
* property, the name is first transformed by converting all hyphens to
* underscores and converting the string to upper case letter, in accordance
* with common convention for environment strings.
* Returns the string value of the property having the given name, trying
* each source of properties added with addGuacamoleProperties() until a
* value is found. If no such property is defined, null is returned.
*
* @param name
* The name of the property value to retrieve.
*
* @return
* The corresponding value for the property. If property override
* is enabled and the value is found in the OS environment, the value
* from the environment is returned. Otherwise, the value from
* guacamole.properties, if any, is returned.
* The value of the property having the given name, or null if no such
* property is defined.
*
* @throws GuacamoleException
* If an error occurs retrieving a property from a GuacamoleProperties
* implementation added via addGuacamoleProperties().
*/
private String getPropertyValue(String name) {
private String getPropertyValue(String name) throws GuacamoleException {
// Check for corresponding environment variable if overrides enabled
if (environmentPropertiesEnabled) {
// Transform the name according to common convention
final String envName = name.replace('-', '_').toUpperCase();
final String envValue = System.getenv(envName);
if (envValue != null) {
return envValue;
}
// Search all provided GuacamoleProperties implementations, in order
for (GuacamoleProperties properties : availableProperties) {
String value = properties.getProperty(name);
if (value != null)
return value;
}
return properties.getProperty(name);
// No such property
return null;
}
@Override
@@ -436,4 +389,9 @@ public class LocalEnvironment implements Environment {
}
@Override
public void addGuacamoleProperties(GuacamoleProperties properties) {
availableProperties.add(properties);
}
}