WebClientSpawner.java

/*
** Module   : WebClientSpawner.java
** Abstract : customizations for spawning a web client
**
** Copyright (c) 2013-2024, Golden Code Development Corporation.
**
** -#- -I- --Date-- --------------------------------Description-----------------------------------
** 001 MAG 20131119 First version.
** 002 MAG 20140206 Send URL as referrer address via configuration file.
** 003 CA  20140206 Changes related to refactoring the spawner infrastructure (allow P2J process 
**                  clients to be started, beside web chui clients).
** 004 GES 20150312 Added support for the GUI web client.
** 005 CA  20150820 Wait for the remote web side to notify that it has initialized all P2J modules
**                  before starting sending requests.
** 006 SBI 20151119 Added the trust server certificate checking.
** 007 GES 20160201 Moved auth token processing here to be better encapsulated/hidden. Modified
**                  the constructor to handle trusted mode (and to pass the referrer directly
**                  instead of requiring a setter to be called later).
**     SBI 20160301 Fixed the web server to redirect the authorized users to the dedicated web
**                  application handler.
** 008 CA  20160428 Added command-line configuration options for web-clients.
** 009 SBI 20160628 Added new methods to allocate and to release web clients.
** 010 SBI 20171023 Changed to allocate new system resources in order to run new web client on
**                  the target host.
** 011 SBI 20210926 Used WebClientsManager to manage agents ports for new web client.
** 012 SBI 20221121 Set the current session language identifier (client:web:lang) for the web client.
** 013 HC  20230323 Added getOrigin and setOrigin methods. There are needed by JS driver to embed
**                  origin URL in the generated HTML content.
** 014 SBI 20230411 Removed unused code as the client process is spawned after its network resources
**                  are allocated.
** 015 GBB 20240709 Adding getClientConfig to set the project token for the TemporaryClient connection, 
**                  resolve the options, merge them in the right order and convert them to bootstrap 
**                  override values. Print diagnostics in TemporaryClient.doWork.
** 016 GBB 20240718 Moving base client builder configs to a field in the respective options class.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
**     of Golden Code Development Corporation. You are not authorized to use the
**     name Golden Code, FWD, or the names of any author or contributor, for
**     publicity purposes without written authorization.
** 
**   2. No Misrepresentation of Affiliation.
** 
**     You may not represent yourself as Golden Code Development Corporation or FWD.
** 
**     You may not represent yourself for publicity purposes as associated with
**     Golden Code Development Corporation, FWD, or any author or contributor to
**     the covered work, without written authorization.
** 
**   3. No Misrepresentation of Source or Origin.
** 
**     You may not represent the covered work as solely your work.  All modified
**     versions of the covered work must be marked in a reasonable way to make it
**     clear that the modified work is not originating from Golden Code Development
**     Corporation or FWD.  All modified versions must contain the notices of
**     attribution required in this license.
*/

package com.goldencode.p2j.main;

import java.net.*;
import java.util.*;
import java.util.function.*;
import java.util.logging.*;

import com.goldencode.p2j.cfg.*;
import com.goldencode.p2j.directory.Base64;
import com.goldencode.p2j.ui.client.*;
import com.goldencode.p2j.ui.client.driver.web.*;
import com.goldencode.p2j.ui.client.chui.driver.web.*;
import com.goldencode.p2j.ui.client.gui.driver.web.*;
import com.goldencode.p2j.ui.client.driver.*;
import com.goldencode.p2j.util.*;
import com.goldencode.p2j.util.logging.*;
import com.goldencode.util.*;

/**
 * Class used to spawn a new web client process.
 * <p>
 * This class is tricky to understand because the main part of it runs on the server while the
 * <code>TemporaryClientTask</code> inner class is serialized and sent down to execute on the
 * client side.  That client side code then calls methods which are implemented as a remote
 * object with the {@link Spawner} interface, which the server portions of this class implement. 
 * <p>
 * In the interactive login mode, the spawned process first tries to authenticate the userid and
 * password at the OS level. On success a new process (client) is spawned with those credentials.
 * <p>
 * In trusted mode, the spawner process will connect to the server using a secure socket and
 * temporary credentials to establish a secure session.  If that works, it will lookup the
 * credentials to use for spawning the client based on a unique UUID for this spawning session.
 * Using those credentials it will start the client and notify the server about success or
 * failure.
 * <p>
 * In both modes, the spawned process will call a remote object method to get the server's
 * KeyStore which is used to start the client's embedded web server.  Finally, the client will
 * call a remote object method to notify this (server side) instance about the URI on which the
 * client's embedded web server is listening. If a notification does not occur within a specific
 * amount of time, a failure in spawning is asserted.  
 */
public class WebClientSpawner
extends ClientSpawner
{
   /** Authorization token query parameter name */
   public static final String PARAM_TOKEN = "token";
   
   /** Logger. */
   private static final CentralLogger LOG = CentralLogger.get(WebClientSpawner.class);

   /** The configuration for this spawner. */
   private final WebClientBuilderParameters buildParams;
   
   /** Remote server URI */
   private volatile String remoteUri = null;
   
   /** Flag that denotes client type (<code>true</code> for GUI, <code>false</code> for ChUI). */
   private boolean gui;

   /** The web clients manager */
   private final WebClientsManager webClientsManager;

   /** Server key store */
   private final ServerKeyStore serverKeyStore;

   /** The {@link WebClientBuilder} used to spawn the P2J client process. */
   private final WebClientBuilder cb;
   
   /**
    * Create a new web client spawner.
    *
    * @param    cfg
    *           The web client builder parameters
    * @param    webClientsManager
    *           The web clients manager
    */
   public WebClientSpawner(WebClientBuilderParameters cfg, WebClientsManager webClientsManager)
   {
      this.buildParams = cfg;
      this.gui = cfg.isGui();
      this.webClientsManager = webClientsManager;
      this.cb =  new WebClientBuilder(buildParams);

      // load server key store
      serverKeyStore = ServerKeyStore.getStore();
   }
   
   /**
    * Get {@link WebClientBuilderParameters} used to spawn P2J clients.
    *
    * @return   See above.
    */
   @Override
   public WebClientBuilderParameters getBuildParams()
   {
      return buildParams;
   }

   /**
    * Notify when the client has started.
    * 
    * @param    data
    *           Custom data sent by the P2J client back to the server.  For web clients, this is
    *           the remote URI to which it will redirect the browser.
    */
   @Override
   public void clientIsReady(String data)
   {
      remoteUri = data;
      super.clientIsReady(data);
   }
   
   /**
    * Get a {@link WebClientBuilder} used to spawn P2J clients.
    *           
    * @return   See above.
    */
   @Override
   protected WebClientBuilder getBuilder()
   {
      return cb;
   }

   /**
    * Get the remote server URI to which the browser will be redirected.
    * 
    * @return   The remote server URI or <code>null</code>.
    * @throws   URISyntaxException 
    */
   public String getRemoteUri() throws URISyntaxException
   {
      String uri = remoteUri;
      
      if (uri != null)
      {
         // set authorization token for the redirect
         Object store = getServerData();
         
         if (store instanceof ServerKeyStore)
         {
            String token = ((ServerKeyStore) store).getAuthorizationToken();
            
            if (token != null)
            {
               uri = uri + "index.html?" + PARAM_TOKEN + "=" + token;
            }
         }
         URI uriObj = new URI(uri);
         uri = uriObj.toASCIIString();
      }
      
      return uri;
   }
   
   /**
    * Get a {@link TemporaryClient} worker which will do the work after authenticating on the P2J
    * server using the temporary credentials.
    *
    * @param    uuid
    *           The client identifier uuid.
    * @param    projectToken
    *           The project token to be set for the temporary session.
    *           
    * @return   See above.
    */
   @Override
   public TemporaryClient getTemporaryClient(String uuid, String projectToken)
   {
      return new TemporaryClientTask(uuid, getServerData(), gui, getClientConfig(uuid, projectToken));
   }

   /**
    * Get the server key store.
    *
    * @return   See above.
    */
   private ServerKeyStore getServerData()
   {
      return (serverKeyStore != null && serverKeyStore.isValid()) ? serverKeyStore : null;
   }

   /**
    * On P2J client side, it will do custom work after authenticating using the temporary 
    * credentials.
    * <p>
    * This will create a {@link ChuiWebDriver} or {@link GuiWebDriver} and start the 
    * embedded web server which will serve this client's requests.
    */
   private static class TemporaryClientTask
   implements TemporaryClient
   {
      /** Logger. */
      private static final CentralLogger LOG = CentralLogger.get(TemporaryClientTask.class);
      
      /** The unique id for the spawned client running the task. */
      private final String uuid;

      /** Key store. */
      private final ServerKeyStore keyStore;
      
      /** Flag that denotes client type. */
      private final boolean gui;

      /** List of client configs. */
      private final List<String> clientConfig;
      
      /**
       * Create a new web client spawner.
       *
       * @param    uuid
       *           The client identifier uuid.
       * @param    keyStore
       *           The key store.
       * @param    gui
       *           Flag that denotes client type (<code>true</code> for GUI, <code>false</code>
       *           for ChUI).
       * @param    clientConfig
       *           The list of client configs.
       */
      TemporaryClientTask(String uuid, ServerKeyStore keyStore, boolean gui, List<String> clientConfig)
      {
         this.uuid = uuid;
         this.keyStore = keyStore;
         this.gui = gui;
         this.clientConfig = clientConfig;
      }
      
      /**
       * On P2J client side, it will do custom work after authenticating using the temporary 
       * credentials.
       * <p>
       * This will create a {@link ChuiWebDriver} or {@link GuiWebDriver} and start the 
       * embedded web server which will serve this client's requests.
       * 
       * @param    spawner
       *           The spawner remote access interface. 
       * @param    config
       *           The configuration to use for setup of the client and for the server connection.
       * @param    diagnostics
       *           Details about the client process.
       *
       * @return   An explicit web screen driver to be used by the P2J client.
       * 
       * @throws   RuntimeException
       *           If the embedded web server could not be started.
       */
      @Override
      public ScreenDriver doWork(Spawner spawner, BootstrapConfig config, Supplier<String> diagnostics)
      {
         if (keyStore == null)
         {
            throw new RuntimeException("Cannot import server key store.");
         }
         
         if (!config.processOverrides(clientConfig))
         {
            LOG.severe("Config overrides are not successfully processed.");
         }
         
         String bytes = Base64.byteArrayToBase64(keyStore.getKeyStore());
         String pw    = keyStore.getKeyStorePassword();
         
         config.setConfigItem("security", "truststore", "alias", keyStore.getTrustServerAlias());
         config.setConfigItem("security", "truststore", "bytes", bytes);
         config.setConfigItem("access", "password", "truststore", pw);
         config.setConfigItem("security", "certificate", "validate", "true");
         config.setConfigItem("security", "trust_mgr", "disable", "false");
         config.setConfigItem("security", "transport", "refresh", "true");

         // get an explicit port and host set by the client
         int port = config.getInt(ConfigItem.PORT, 0);
         String host = config.getString(ConfigItem.HOST, null);
         
         boolean dedicatedMode = config.getBoolean("client", "web", "dedicatedMode", false);
         
         // dedicated mode section placed just before the driver created
         if (dedicatedMode)
         {
            host = "localhost";
            config.setConfigItem(ConfigItem.HOST, host);
         }
         
         ClientCore.outputDiagnostics(config, diagnostics);
         
         // create web screen driver
         ScreenDriver<?> driver = gui ? new GuiWebDriver(config) : new ChuiWebDriver(config);
         driver.init();
         
         String uri = ((EmbeddedWebServer) driver).startupServer(keyStore, config, host, port);
         
         String forwardedHost = config.getString(ConfigItem.PROXY_HOST, null);
         
        if (forwardedHost != null    &&
            !forwardedHost.isEmpty() &&
             uri != null)
         {
            String forwardedProto = config.getString(ConfigItem.PROXY_PROTOCOL, null);
            String webRoot = config.getString(ConfigItem.WEB_ROOT, null);
            uri = getForwardedUri(forwardedProto, forwardedHost, webRoot);
         }

         if (uri == null)
         {
            spawner.releaseClient(uuid);
            throw new RuntimeException("Cannot start embedded server."); 
         }

         if (gui)
         {
            try
            {
               ((GuiWebDriver) driver).setOriginUrl(new URL(uri));
            }
            catch (MalformedURLException e)
            {
               // this should never happen
               throw new RuntimeException(e);
            }
         }

         // client initialization is done, report embedded server URI back to the server
         spawner.clientIsReady(uuid, uri);
         
         ((EmbeddedWebServer) driver).waitInitialization();
         
         return driver;
      }
   }

   /**
    * Releases the system resources for this spawned client.
    */
   @Override
   public void releaseClient()
   {
      if (webClientsManager != null)
      {
         webClientsManager.freeWebClientResources(buildParams.getUuid());
      }
   }
   
   /**
    * Returns a list of client configs in the option format "category:group:key=value".
    *
    * @param    uuid
    *           Remote client identifier uuid.
    * @param    projectToken
    *           The project token.
    *
    * @return   See above. 
    */
   public List<String> getClientConfig(String uuid, String projectToken)
   {
      // the remote call is only applicable for web
      if (!WebClientBuilder.UUID_OPTIONS.containsKey(uuid))
      {
         return null;
      }

      WebClientBuilder.PostInitOptions postInitOptions = WebClientBuilder.UUID_OPTIONS.remove(uuid);
      WebDriverType driverType = postInitOptions.getDriverType();

      Map<String, String> options = new HashMap<>();
      List<String> cfgOverrides = null;
      List<String> webOverrides = null;
      
      if (projectToken == null || projectToken.isEmpty())
      {
         WebClientBuilderOptions webOptions = WebDriverHandler.driverOptionsMap.get(driverType);
         options.putAll(webOptions.getDefaults());
         cfgOverrides = webOptions.getBaseOptions().getCfgOverrides();
         webOverrides = postInitOptions.getWebOverrides();
      }
      else
      {
         StandardServer.setProjectToken(projectToken);

         options.putAll(WebClientBuilderOptions.readConfigs());
         
         String cfgOverridesString = ConfigItem.CFG_OVERRIDES.read(null);
         if (cfgOverridesString != null)
         {
            cfgOverrides = Arrays.asList(cfgOverridesString.split(" "));
         }

         String dirWebOverridesString = ConfigItem.CFG_OVERRIDES_WEB.read(null);
         if (dirWebOverridesString != null)
         {
            List<String> dirWebOverrides = Arrays.asList(dirWebOverridesString.split(" "));
            webOverrides = postInitOptions.getWebOverrides(dirWebOverrides);
         }
      }

      options.putAll(postInitOptions.getRuntimeOptions());
      List<String> bootstrapValues = prepareBootstrapValues(options,
                                                            driverType.isGui(),
                                                            postInitOptions.getRemote(),
                                                            cfgOverrides,
                                                            webOverrides);

      // removes options that should not be overridden client-side
      bootstrapValues.removeIf(value -> value == null || value.contains(ConfigItem.PROJECT_TOKEN.fullOption()));

      return bootstrapValues;
   }

   /**
    * Get the external web client uri assigned by the reverse proxy server.
    * 
    * @return   The external uri of this web client
    */
   private static String getForwardedUri(String forwardedProto, String forwardedHost, String webRoot)
   {
      URI uri = URI.create(forwardedProto + "://" + forwardedHost +  webRoot + "/");
      //rewrite uri
      return uri.toString();
   }

   /**
    * @param    options
    *           Base options.
    * @param    isGui
    *           Flag to indicate if it's a gui web driver.
    * @param    isRemote
    *           Flag to indicate if it's a remote spawn.
    * @param    cfgOverrides
    *           clientConfig/cfgOverrides resolved with the project token.
    * @param    webOverrides
    *           webClient/webOverrides + runtime. Default startup procedure (for embedded). Forked session 
    *           cfgOverrides. client:web:embedded. Selected UI theme. webRoot, login / logout url.
    *           
    * @return   List of bootstrap configs in the format category:group:key=value.
    */
   private List<String> prepareBootstrapValues(Map<String, String> options,
                                               boolean isGui,
                                               boolean isRemote,
                                               List<String> cfgOverrides,
                                               List<String> webOverrides)
   {
      List<String> cmd = new ArrayList<>();

      if (isGui)
      {
         // GUI driver options
         cmd.add(ConfigItem.DRIVER_TYPE.fullOption() + "=" + OutputManager.GUI_DRIVER_WEB);
         add(cmd, ConfigItem.DESKTOP_HEIGHT, options);
         add(cmd, ConfigItem.DESKTOP_WIDTH, options);
         add(cmd, ConfigItem.TASKBAR, options);
         add(cmd, ConfigItem.GRAPHICS_CACHED, options);
         add(cmd, ConfigItem.DISABLE_PIXEL_MANIPULATION, options);
         add(cmd, ConfigItem.RENDERER, options);
         add(cmd, ConfigItem.TASKBAR_STYLE, options);
      }
      else
      {
         // ChUI driver options
         cmd.add(ConfigItem.DRIVER_TYPE.fullOption() + "=" + OutputManager.CHUI_DRIVER_WEB);
         add(cmd, ConfigItem.ROWS, options);
         add(cmd, ConfigItem.COLS, options);
         add(cmd, ConfigItem.BACKGROUND, options);
         add(cmd, ConfigItem.FOREGROUND, options);
         add(cmd, ConfigItem.SELECTION, options);
         add(cmd, ConfigItem.FONT_NAME, options);
         add(cmd, ConfigItem.FONT_SIZE, options);
         add(cmd, ConfigItem.CLIPBOARD, options);
      }
      // Common Websocket parameters:
      add(cmd, ConfigItem.WEB_SOCKET_TIMEOUT, options);
      add(cmd, ConfigItem.WATCHDOG_TIMEOUT, options);

      add(cmd, ConfigItem.MAX_BINARY_MSG_SIZE, options);
      add(cmd, ConfigItem.MAX_TEXT_MSG_SIZE, options);
      add(cmd, ConfigItem.MAX_IDLE_TIME, options);

      add(cmd, ConfigItem.CONNECT_RETRY_DELAY, options);
      add(cmd, ConfigItem.TRY_CONNECT_MSG, options);
      add(cmd, ConfigItem.SERVER_UNAVAILABLE_MSG, options);
      add(cmd, ConfigItem.CONNECTION_RESTORED_MSG, options);
      add(cmd, ConfigItem.PING_PONG_INTERVAL, options);
      add(cmd, ConfigItem.MAX_LOST_PINGS, options);
      add(cmd, ConfigItem.PING_DELAY, options);

      //http configuration settings for the embedded web server
      add(cmd, ConfigItem.MAX_OUT_BUFFER_SIZE, options);
      add(cmd, ConfigItem.MAX_OUT_AGGREGATION_SIZE, options);
      add(cmd, ConfigItem.MAX_HTTP_IDLE_TIME, options);
      add(cmd, ConfigItem.MAX_RESPONSE_HEADER_SIZE, options);
      add(cmd, ConfigItem.MAX_REQUEST_HEADER_SIZE, options);
      
      add(cmd, ConfigItem.JS_DEBUG_LOGGING, options);

      add(cmd, ConfigItem.CACHE_SIZE, options);

      if (options.get(ConfigItem.PORT.name()) != null)
      {
         add(cmd, ConfigItem.PORT, options);
      }

      String cfgHost = options.get(ConfigItem.HOST.name());
      if (cfgHost != null)
      {
         // do not send this parameter on remote spawn, let the remote web server select the IP
         if (!isRemote)
         {
            cmd.add(ConfigItem.HOST.fullOption() + "=" + cfgHost);
         }
      }

      String lang = options.get(ConfigItem.LANG.name());
      if (lang != null)
      {
         cmd.add(ConfigItem.LANG.fullOption() + "=" + lang);
      }

      String forwardedHost = options.get(ConfigItem.PROXY_HOST.name());
      if (forwardedHost != null)
      {
         add(cmd, ConfigItem.PROXY_PROTOCOL, options);
         add(cmd, ConfigItem.PROXY_HOST, options);
         String webRoot = options.get(ConfigItem.WEB_ROOT.name());
         if (webRoot != null)
         {
            cmd.add(ConfigItem.WEB_ROOT.fullOption() + "=" + webRoot);
         }
      }

      add(cmd, ConfigItem.USE_LOCALSTORAGE, options);
      add(cmd, ConfigItem.BROADCAST_CHANNEL_PING_TIMEOUT, options);
      
      if (cfgOverrides != null)
      {
         cmd.addAll(cfgOverrides);
      }
      
      if (webOverrides != null)
      {
         cmd.addAll(webOverrides);
      }
      return cmd;
   }

   /**
    * Convenience method to shorten the syntax of adding new options to the list of client params.
    *
    * @param    cmd
    *           The list of entries comprising the command.
    * @param    clientConfig
    *           The config to add to the command.
    * @param    webClientOptions
    *           The options to get the value from.
    */
   private void add(List<String> cmd, ConfigItem clientConfig, Map<String, String> webClientOptions)
   {
      cmd.add(clientConfig.fullOption() + "=" + webClientOptions.get(clientConfig.name()));
   }
}