Prevent any of calibre, calibre-server, calibredb from running simultaneously

manual/custom.py

@@ -90,7 +90,32 @@ def generate_calibredb_help(preamble, app):
     preamble += textwrap.dedent('''
 
     :command:`calibredb` is the command line interface to the calibre database. It has
-    several sub-commands, documented below:
+    several sub-commands, documented below.
+
+    :command:`calibredb` can be used to manipulate either a calibre database
+    specified by path or a calibre :guilabel:`Content server` running either on
+    the local machine or over the internet. You can start a calibre
+    :guilabel:`Content server` using either the :command:`calibre-server`
+    program or in the main calibre program click :guilabel:`Connect/share ->
+    Start Content server`. Since :command:`calibredb` can make changes to your
+    calibre libraries, you must setup authentication on the server first. There
+    are two ways to do that:
+
+        * If you plan to connect only to a server running on the same computer,
+          you can simply use the ``--enable-local-write`` option of the
+          content server, to allow any program, including calibredb, running on
+          the local computer to make changes to your calibre data. When running
+          the server from the main calibre program, this option is in
+          :guilabel:`Preferences->Sharing over the net->Advanced`.
+
+        * If you want to enable access over the internet, then you should setup
+          user accounts on the server and use the :option:`--username` and :option:`--password`
+          options to :command:`calibredb` to give it access. You can setup
+          user authentication for :command:`calibre-server` by using the ``--enable-auth``
+          option and using ``--manage-users`` to create the user accounts.
+          If you are running the server from the main calibre program, use
+          :guilabel:`Preferences->Sharing over the net->Require username/password`.
+
 
     ''')
 

src/calibre/db/cli/main.py

@@ -12,10 +12,12 @@ from urllib import urlencode
 from urlparse import urlparse, urlunparse
 
 from calibre import browser, prints
-from calibre.constants import __appname__, __version__
+from calibre.constants import __appname__, __version__, iswindows
 from calibre.db.cli import module_for_cmd
 from calibre.db.legacy import LibraryDatabase
 from calibre.utils.config import OptionParser, prefs
+from calibre.utils.localization import localize_user_manual_link
+from calibre.utils.lock import singleinstance
 from calibre.utils.serialize import MSGPACK_MIME
 
 COMMANDS = (
@@ -51,8 +53,8 @@ def run_cmd(cmd, opts, args, dbctx):
     if dbctx.is_remote and getattr(m, 'no_remote', False):
         raise SystemExit(_('The {} command is not supported with remote (server based) libraries').format(cmd))
     ret = m.main(opts, args, dbctx)
-    if not dbctx.is_remote and not opts.dont_notify_gui and not getattr(m, 'readonly', False):
-        send_message()
+    # if not dbctx.is_remote and not opts.dont_notify_gui and not getattr(m, 'readonly', False):
+    #     send_message()
     return ret
 
 
@@ -71,17 +73,11 @@ def get_parser(usage):
             ' for example, http://localhost:8080/#mylibrary. library_id is the library id'
             ' of the library you want to connect to on the Content server. You can use'
             ' the special library_id value of - to get a list of library ids available'
-            ' on the server.'
-        )
-    )
-    go.add_option(
-        '--dont-notify-gui',
-        default=False,
-        action='store_true',
-        help=_(
-            'Do not notify the running calibre GUI (if any) that the database has'
-            ' changed. Use with care, as it can lead to database corruption!'
-        )
+            ' on the server. For details on how to setup access via a Content server, see'
+            ' {}.'
+        ).format(localize_user_manual_link(
+            'https://manual.calibre-ebook.com/generated/en/calibredb.html'
+        ))
     )
     go.add_option(
         '-h', '--help', help=_('show this help message and exit'), action='help'
@@ -107,7 +103,7 @@ def get_parser(usage):
 
 
 def option_parser():
-    parser = OptionParser(
+    return get_parser(
         _(
             '''\
 %%prog command [options] [arguments]
@@ -121,7 +117,6 @@ For help on an individual command: %%prog command --help
 '''
         ) % '\n  '.join(COMMANDS)
     )
-    return parser
 
 
 def read_credetials(opts):
@@ -163,6 +158,16 @@ class DBCtx(object):
                 raise SystemExit()
         else:
             self.library_path = os.path.expanduser(self.library_path)
+            if not singleinstance('db'):
+                ext = '.exe' if iswindows else ''
+                raise SystemExit(_(
+                    'Another calibre program such as {} or the main calibre program is running.'
+                    ' Having multiple programs that can make changes to a calibre library'
+                    ' running at the same time is a bad idea. calibredb can connect directly'
+                    ' to a running calibre content server, to make changes through it, instead.'
+                    ' See the documentation of the {} option for details.'
+                ).format('calibre-server' + ext, '--with-library')
+                )
             self._db = None
             self.is_remote = False
 

src/calibre/gui2/main.py

@@ -26,6 +26,7 @@ from calibre.gui2.main_window import option_parser as _option_parser
 from calibre.gui2.splash_screen import SplashScreen
 from calibre.utils.config import dynamic, prefs
 from calibre.utils.ipc import RC, gui_socket_address
+from calibre.utils.lock import singleinstance
 
 if iswindows:
     winutil = plugins['winutil'][0]
@@ -364,6 +365,16 @@ def shellquote(s):
 
 
 def run_gui(opts, args, listener, app, gui_debug=None):
+    si = singleinstance('db')
+    if not si:
+        ext = '.exe' if iswindows else ''
+        error_dialog(None, _('Cannot start calibre'), _(
+            'Another calibre program that can modify calibre libraries, such as,'
+            ' {} or {} is already running. You must first shut it down, before'
+            ' starting the main calibre program. If you are sure no such'
+            ' program is running, try restarting your computer.').format(
+                'calibre-server' + ext, 'calibredb' + ext), show=True)
+        return 1
     initialize_file_icon_provider()
     app.load_builtin_fonts(scan_for_fonts=True)
     if not dynamic.get('welcome_wizard_was_run', False):
@@ -462,7 +473,6 @@ def shutdown_other(rc=None):
         if rc.conn is None:
             prints(_('No running calibre found'))
             return  # No running instance found
-    from calibre.utils.lock import singleinstance
     rc.conn.send('shutdown:')
     prints(_('Shutdown command sent, waiting for shutdown...'))
     for i in xrange(50):
@@ -518,7 +528,6 @@ def main(args=sys.argv):
     except AbortInit:
         return 1
     try:
-        from calibre.utils.lock import singleinstance
         si = singleinstance(singleinstance_name)
     except Exception:
         error_dialog(None, _('Cannot start calibre'), _(

src/calibre/srv/TODO

@@ -1,6 +1,3 @@
-Prevent standalone and embedded servers from running simultaneously
-Prevent more than a single instance of the standalone server from running
-
 Fix search completion popups
 Read progress
 Bookmarks/annotations

src/calibre/srv/standalone.py

@@ -18,6 +18,7 @@ from calibre.srv.http_response import create_http_handler
 from calibre.srv.handler import Handler
 from calibre.srv.utils import RotatingLog
 from calibre.utils.config import prefs
+from calibre.utils.lock import singleinstance
 from calibre.db.legacy import LibraryDatabase
 
 
@@ -297,6 +298,15 @@ def main(args=sys.argv):
             raise SystemExit(_('You must specify at least one calibre library'))
         libraries=[prefs['library_path']]
 
+    if not singleinstance('db'):
+        ext = '.exe' if iswindows else ''
+        raise SystemExit(_(
+            'Another calibre program such as another instance of {} or the main'
+            ' calibre program is running. Having multiple programs that can make'
+            ' changes to a calibre library running at the same time is not supported.'
+        ).format('calibre-server' + ext)
+        )
+
     if opts.auto_reload:
         if opts.daemonize:
             raise SystemExit('Cannot specify --auto-reload and --daemonize at the same time')