Support configuration live reload

gns3server/config.py

@@ -22,6 +22,7 @@ Reads the configuration file and store the settings for the server & modules.
 import sys
 import os
 import configparser
+import asyncio
 
 import logging
 log = logging.getLogger(__name__)
@@ -33,12 +34,18 @@ class Config(object):
 
     """
     Configuration file management using configparser.
+
+    :params files: Array of configuration files (optionnal)
     """
 
-    def __init__(self):
+    def __init__(self, files=None):
+
+        self._files = files
+        self._watched_files = {}
+
+        if sys.platform.startswith("win"):
 
             appname = "GNS3"
-        if sys.platform.startswith("win"):
 
             # On windows, the configuration file location can be one of the following:
             # 1: %APPDATA%/GNS3/server.ini
@@ -51,6 +58,7 @@ class Config(object):
             common_appdata = os.path.expandvars("%COMMON_APPDATA%")
             self._cloud_file = os.path.join(appdata, appname, "cloud.ini")
             filename = "server.ini"
+            if self._files is None:
                 self._files = [os.path.join(appdata, appname, filename),
                                os.path.join(appdata, appname + ".ini"),
                                os.path.join(common_appdata, appname, filename),
@@ -70,6 +78,7 @@ class Config(object):
             home = os.path.expanduser("~")
             self._cloud_file = os.path.join(home, ".config", appname, "cloud.conf")
             filename = "server.conf"
+            if self._files is None:
                 self._files = [os.path.join(home, ".config", appname, filename),
                                os.path.join(home, ".config", appname + ".conf"),
                                os.path.join("/etc/xdg", appname, filename),
@@ -81,6 +90,24 @@ class Config(object):
         self.read_config()
         self._cloud_config = configparser.ConfigParser()
         self.read_cloud_config()
+        self._watch_config_file()
+
+    def _watch_config_file(self):
+        asyncio.get_event_loop().call_later(1, self._check_config_file_change)
+
+    def _check_config_file_change(self):
+        """
+        Check if configuration file has changed on the disk
+        """
+
+        changed = False
+        for file in self._watched_files:
+            if os.stat(file).st_mtime != self._watched_files[file]:
+                changed = True
+        if changed:
+            self.read_config()
+        # TODO: Support command line override
+        self._watch_config_file()
 
     def list_cloud_config_file(self):
         return self._cloud_file
@@ -101,6 +128,10 @@ class Config(object):
         parsed_files = self._config.read(self._files)
         if not parsed_files:
             log.warning("No configuration file could be found or read")
+        else:
+            for file in parsed_files:
+                log.info("Load configuration file {}".format(file))
+                self._watched_files[file] = os.stat(file).st_mtime
 
     def get_default_section(self):
         """
@@ -132,7 +163,10 @@ class Config(object):
         :param content: A dictionary with section content
         """
 
-        self._config[section] = content
+        if not self._config.has_section(section):
+            self._config.add_section(section)
+        for key in content:
+            self._config.set(section, key, content[key])
 
     @staticmethod
     def instance():

gns3server/main.py

@@ -105,16 +105,18 @@ def main():
     Entry point for GNS3 server
     """
 
+    # We init the logger with info level during config file parsing
+    user_log = init_logger(logging.INFO)
+    user_log.info("GNS3 server version {}".format(__version__))
     current_year = datetime.date.today().year
-    args = parse_arguments()
+    user_log.info("Copyright (c) 2007-{} GNS3 Technologies Inc.".format(current_year))
+
     level = logging.INFO
+    args = parse_arguments()
     if args.debug:
         level = logging.DEBUG
     user_log = init_logger(level, quiet=args.quiet)
 
-    user_log.info("GNS3 server version {}".format(__version__))
-    user_log.info("Copyright (c) 2007-{} GNS3 Technologies Inc.".format(current_year))
-
     server_config = Config.instance().get_section_config("Server")
     if server_config.getboolean("local"):
         log.warning("Local mode is enabled. Beware, clients will have full control on your filesystem")

tests/test_config.py

@@ -0,0 +1,97 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2015 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import configparser
+import time
+import os
+
+from gns3server.config import Config
+
+
+def load_config(tmpdir, settings):
+    """
+    Create a configuration file for
+    the test.
+
+    :params tmpdir: Temporary directory
+    :params settings: Configuration settings
+    :returns: Configuration instance
+    """
+
+    path = write_config(tmpdir, settings)
+    return Config(files=[path])
+
+
+def write_config(tmpdir, settings):
+    """
+    Write a configuration file for the test.
+
+    :params tmpdir: Temporary directory
+    :params settings: Configuration settings
+    :returns: File path
+    """
+
+    path = str(tmpdir / "server.conf")
+
+    config = configparser.ConfigParser()
+    config.read_dict(settings)
+    with open(path, "w+") as f:
+        config.write(f)
+    return path
+
+
+def test_get_section_config(tmpdir):
+
+    config = load_config(tmpdir, {
+        "Server": {
+            "host": "127.0.0.1"
+        }
+    })
+    assert dict(config.get_section_config("Server")) == {"host": "127.0.0.1"}
+
+
+def test_set_section_config(tmpdir):
+
+    config = load_config(tmpdir, {
+        "Server": {
+            "host": "127.0.0.1"
+        }
+    })
+    assert dict(config.get_section_config("Server")) == {"host": "127.0.0.1"}
+    config.set_section_config("Server", {"host": "192.168.1.1"})
+    assert dict(config.get_section_config("Server")) == {"host": "192.168.1.1"}
+
+
+def test_check_config_file_change(tmpdir):
+
+    config = load_config(tmpdir, {
+        "Server": {
+            "host": "127.0.0.1"
+        }
+    })
+    assert dict(config.get_section_config("Server")) == {"host": "127.0.0.1"}
+
+    path = write_config(tmpdir, {
+        "Server": {
+            "host": "192.168.1.1"
+        }
+    })
+    os.utime(path, (time.time() + 1, time.time() + 1))
+
+    config._check_config_file_change()
+    assert dict(config.get_section_config("Server")) == {"host": "192.168.1.1"}