Merge branch 'feature/daemon-startup-fixes' into develop

Author: GrahamDumpleton

docs/release-notes/index.rst

@@ -5,6 +5,7 @@ Release Notes
 .. toctree::
    :maxdepth: 2
 
+   version-4.2.4.rst
    version-4.2.3.rst
    version-4.2.2.rst
    version-4.2.1.rst

docs/release-notes/version-4.2.4.rst

@@ -0,0 +1,37 @@
+=============
+Version 4.2.4
+=============
+
+Version 4.2.4 of mod_wsgi can be obtained from:
+
+  https://github.com/GrahamDumpleton/mod_wsgi/archive/4.2.4.tar.gz
+
+Known Issues
+------------
+
+1. The makefiles for building mod_wsgi on Windows are currently broken and
+need updating. As most new changes relate to mod_wsgi daemon mode, which is
+not supported under Windows, you should keep using the last available
+binary for version 3.X on Windows instead.
+
+Bugs Fixed
+----------
+
+1. Fixed one off error in applying limit to the number of supplementary
+groups allowed for a daemon process group. The result could be that if
+more groups than the operating system allowed were specified to the option
+``supplementary-groups``, then memory corruption or a process crash could
+occur.
+
+2. Improved error handling in setting up the current working directory and
+group access rights for a process when creating a daemon process group. The
+change means that if any error occurs that the daemon process group will be
+restarted rather than allow it to keep running with an incorrect working
+directory or group access rights.
+
+New Features
+------------
+
+1. Added the ``--setup-only`` option to mod_wsgi express so that it is
+possible to create the configuration when using the Django management command
+``runmodwsgi`` without actually starting the server.

src/server/__init__.py

@@ -1060,6 +1060,14 @@ def check_percentage(option, opt_str, value, parser):
     optparse.make_option('--enable-docs', action='store_true', default=False,
             help='Flag indicating whether the mod_wsgi documentation should '
             'be made available at the /__wsgi__/docs sub URL.'),
+
+    optparse.make_option('--setup-only', action='store_true', default=False,
+            help='Flag indicating that after the configuration files have '
+            'been setup, that the command should then exit and not go on '
+            'to actually run up the Apache server. This is to allow for '
+            'the generation of the configuration with Apache then later '
+            'being started separately using the generated \'apachectl\' '
+            'script.'),
 )
 
 def cmd_setup_server(params):
@@ -1350,7 +1358,7 @@ def _cmd_setup_server(command, args, options):
     if options['envvars_script']:
         print('Environ Variables :', options['envvars_script'])
 
-    if command == 'setup-server':
+    if command == 'setup-server' or options['setup_only']:
         if not options['envvars_script']:
             print('Environ Variables :', options['server_root'] + '/envvars')
         print('Control Script    :', options['server_root'] + '/apachectl')
@@ -1369,6 +1377,9 @@ def cmd_start_server(params):
 
     config = _cmd_setup_server('start-server', args, vars(options))
 
+    if config['setup_only']:
+        return
+
     executable = os.path.join(config['server_root'], 'apachectl')
     name = executable.ljust(len(config['process_name']))
     os.execl(executable, name, 'start', '-DNO_DETACH')

src/server/management/commands/runmodwsgi.py

@@ -8,7 +8,7 @@
 
 class Command(BaseCommand):
     option_list = BaseCommand.option_list + mod_wsgi.server.option_list
-    args = '[options]'
+    args = ''
     help = 'Starts Apache/mod_wsgi web server.'
 
     def handle(self, *args, **options):
@@ -47,6 +47,9 @@ def handle(self, *args, **options):
         options = mod_wsgi.server._cmd_setup_server(
                 'start-server', args, options)
 
+        if options['setup_only']:
+            return
+
         executable = os.path.join(options['server_root'], 'apachectl')
         name = executable.ljust(len(options['process_name']))
         os.execl(executable, name, 'start', '-DNO_DETACH')

src/server/mod_wsgi.c

@@ -6690,7 +6690,7 @@ static const char *wsgi_add_daemon_process(cmd_parms *cmd, void *mconfig,
         group_name = ap_getword(cmd->pool, &items, ',');
 
         while (group_name && *group_name) {
-            if (groups_count > groups_maximum)
+            if (groups_count >= groups_maximum)
                 return "Too many supplementary groups WSGI daemon process";
 
             groups[groups_count++] = ap_gname2id(group_name);
@@ -7087,7 +7087,7 @@ static void wsgi_setup_daemon_name(WSGIDaemonProcess *daemon, apr_pool_t *p)
 #endif
 }
 
-static void wsgi_setup_access(WSGIDaemonProcess *daemon)
+static int wsgi_setup_access(WSGIDaemonProcess *daemon)
 {
     /* Setup the umask for the effective user. */
 
@@ -7101,6 +7101,8 @@ static void wsgi_setup_access(WSGIDaemonProcess *daemon)
             ap_log_error(APLOG_MARK, APLOG_ALERT, errno, wsgi_server,
                          "mod_wsgi (pid=%d): Unable to change root "
                          "directory to '%s'.", getpid(), daemon->group->root);
+
+            return -1;
         }
     }
 
@@ -7111,6 +7113,8 @@ static void wsgi_setup_access(WSGIDaemonProcess *daemon)
             ap_log_error(APLOG_MARK, APLOG_ALERT, errno, wsgi_server,
                          "mod_wsgi (pid=%d): Unable to change working "
                          "directory to '%s'.", getpid(), daemon->group->home);
+
+            return -1;
         }
     }
     else if (geteuid()) {
@@ -7123,12 +7127,16 @@ static void wsgi_setup_access(WSGIDaemonProcess *daemon)
                 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, wsgi_server,
                              "mod_wsgi (pid=%d): Unable to change working "
                              "directory to '%s'.", getpid(), pwent->pw_dir);
+
+            return -1;
             }
         }
         else {
             ap_log_error(APLOG_MARK, APLOG_ALERT, errno, wsgi_server,
                          "mod_wsgi (pid=%d): Unable to determine home "
                          "directory for uid=%ld.", getpid(), (long)geteuid());
+
+            return -1;
         }
     }
     else {
@@ -7141,27 +7149,33 @@ static void wsgi_setup_access(WSGIDaemonProcess *daemon)
                 ap_log_error(APLOG_MARK, APLOG_ALERT, errno, wsgi_server,
                              "mod_wsgi (pid=%d): Unable to change working "
                              "directory to '%s'.", getpid(), pwent->pw_dir);
+
+                return -1;
             }
         }
         else {
             ap_log_error(APLOG_MARK, APLOG_ALERT, errno, wsgi_server,
                          "mod_wsgi (pid=%d): Unable to determine home "
                          "directory for uid=%ld.", getpid(),
                          (long)daemon->group->uid);
+
+            return -1;
         }
     }
 
     /* Don't bother switch user/group if not root. */
 
     if (geteuid())
-        return;
+        return 0;
 
     /* Setup the daemon process real and effective group. */
 
     if (setgid(daemon->group->gid) == -1) {
         ap_log_error(APLOG_MARK, APLOG_ALERT, errno, wsgi_server,
                      "mod_wsgi (pid=%d): Unable to set group id to gid=%u.",
                      getpid(), (unsigned)daemon->group->gid);
+
+        return -1;
     }
     else {
         if (daemon->group->groups) {
@@ -7172,13 +7186,17 @@ static void wsgi_setup_access(WSGIDaemonProcess *daemon)
                              "to set supplementary groups for uname=%s "
                              "of '%s'.", getpid(), daemon->group->user,
                              daemon->group->groups_list);
+
+                return -1;
             }
         }
         else if (initgroups(daemon->group->user, daemon->group->gid) == -1) {
             ap_log_error(APLOG_MARK, APLOG_ALERT, errno,
                          wsgi_server, "mod_wsgi (pid=%d): Unable "
                          "to set groups for uname=%s and gid=%u.", getpid(),
                          daemon->group->user, (unsigned)daemon->group->gid);
+
+            return -1;
         }
     }
 
@@ -7196,8 +7214,19 @@ static void wsgi_setup_access(WSGIDaemonProcess *daemon)
          * reached their process limit. In that case will be left
          * running as wrong user. Just exit on all failures to be
          * safe. Don't die immediately to avoid a fork bomb.
+         *
+         * We could just return -1 here and let the caller do the
+         * sleep() and exit() but this failure is critical enough
+         * that we still do it here so it is obvious that the issue
+         * is being addressed.
          */
 
+        ap_log_error(APLOG_MARK, APLOG_ALERT, 0, wsgi_server,
+                     "mod_wsgi (pid=%d): Failure to configure the "
+                     "daemon process correctly and process left in "
+                     "unspecified state. Restarting daemon process "
+                     "after delay.", getpid());
+
         sleep(20);
 
         exit(-1);
@@ -7219,6 +7248,8 @@ static void wsgi_setup_access(WSGIDaemonProcess *daemon)
         }
     }
 #endif
+
+    return 0;
 }
 
 static int wsgi_setup_socket(WSGIProcessGroup *process)
@@ -8561,7 +8592,24 @@ static int wsgi_start_process(apr_pool_t *p, WSGIDaemonProcess *daemon)
 
         /* Setup daemon process user/group/umask etc. */
 
-        wsgi_setup_access(daemon);
+        if (wsgi_setup_access(daemon) == -1) {
+            /*
+             * If we get any failure from setting up the appropriate
+             * permissions or working directory for the daemon process
+             * then we exit the process. Don't die immediately to avoid
+             * a fork bomb.
+             */
+
+            ap_log_error(APLOG_MARK, APLOG_ALERT, 0, wsgi_server,
+                         "mod_wsgi (pid=%d): Failure to configure the "
+                         "daemon process correctly and process left in "
+                         "unspecified state. Restarting daemon process "
+                         "after delay.", getpid());
+
+            sleep(20);
+
+            exit(-1);
+        }
 
         /* Reinitialise accept mutex in daemon process. */
 

src/server/wsgi_version.h

@@ -25,8 +25,8 @@
 
 #define MOD_WSGI_MAJORVERSION_NUMBER 4
 #define MOD_WSGI_MINORVERSION_NUMBER 2
-#define MOD_WSGI_MICROVERSION_NUMBER 3
-#define MOD_WSGI_VERSION_STRING "4.2.3"
+#define MOD_WSGI_MICROVERSION_NUMBER 4
+#define MOD_WSGI_VERSION_STRING "4.2.4"
 
 /* ------------------------------------------------------------------------- */