From 2116c2b62512c7ec9f10a9ac523962f0671e94c1 Mon Sep 17 00:00:00 2001
From: "A. Wilcox" <AWilcox@Wilcox-Tech.com>
Date: Mon, 31 Aug 2020 11:43:38 -0500
Subject: Add server and configuration modules

---
 ncserver/config.py | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 ncserver/server.py | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++
 requirements.txt   |  2 ++
 3 files changed, 167 insertions(+)
 create mode 100644 ncserver/config.py
 create mode 100644 ncserver/server.py

diff --git a/ncserver/config.py b/ncserver/config.py
new file mode 100644
index 0000000..047e3a5
--- /dev/null
+++ b/ncserver/config.py
@@ -0,0 +1,85 @@
+"""
+NETCONF for APK Distributions server:
+    Configuration manager module
+
+Copyright © 2020 Adélie Software in the Public Benefit, Inc.
+
+Released under the terms of the NCSA license.  See the LICENSE file included
+with this source distribution for more information.
+
+SPDX-License-Identifier: NCSA
+"""
+
+import logging
+import yaml
+
+from taillight import Signal
+
+from ncserver.base.util import _
+
+
+CONFIG_RELOADED = Signal(('ConfigManager', 'reloaded'))
+"""Signal fired when configuration is reloaded."""
+
+
+class ConfigManager:
+    """The configuration manager for NETCONF for APK Distributions."""
+
+    def __init__(self):
+        """Initialise the configuration manager."""
+        self._config = {'server': {'port': 830, 'debug': False, 'modules': [],
+                                   'users': ['netconf']}}
+        self._logger = logging.getLogger("ConfigManager")
+        self.reload_config()
+
+    def reload_config(self):
+        """Reload the configuration from disk."""
+        try:
+            with open('/etc/netconf/netconf.conf', 'r') as conf:
+                self._config = yaml.safe_load(conf)
+        except IOError as exc:
+            self._logger.error(_("Couldn't open configuration file: %s"), exc)
+        except BaseException as exc:  # pylint: disable=W0703
+            self._logger.error(_("Couldn't read configuration file: %s"), exc)
+        else:
+            CONFIG_RELOADED.call()
+
+    def get(self, clade: str, key: str):
+        """Retrieve the value for the specified configuration key.
+
+        :param str clade:
+        The configuration clade (typically 'server').
+
+        :param str key:
+        The configuration key desired.
+
+        :returns str:
+        The value of the specified configuration key.
+
+        :raises KeyError:
+        The key is not configured or set.
+        """
+        return self._config[clade][key]
+
+    def get_list(self, clade: str, key: str) -> list:
+        """Retrieve a list value for the specified configuration key.
+
+        :param str clade:
+        The configuration clade (typically 'server').
+
+        :param str key:
+        The configuration key desired.
+
+        :returns list:
+        The value of the specified configuration key.
+
+        :raises KeyError:
+        The key is not configured or set.
+
+        :raises TypeError:
+        The value for this key is not a list.
+        """
+        value = self._config[clade][key]
+        if not isinstance(value, list):
+            raise TypeError(_("{}/{} is not a list value").format(clade, key))
+        return value
diff --git a/ncserver/server.py b/ncserver/server.py
new file mode 100644
index 0000000..a0eed8e
--- /dev/null
+++ b/ncserver/server.py
@@ -0,0 +1,80 @@
+"""
+NETCONF for APK Distributions server:
+    Server module
+
+Copyright © 2020 Adélie Software in the Public Benefit, Inc.
+
+Released under the terms of the NCSA license.  See the LICENSE file included
+with this source distribution for more information.
+
+SPDX-License-Identifier: NCSA
+"""
+
+import logging
+
+from netconf import util
+from netconf.server import NetconfSSHServer, SSHAuthorizedKeysController
+
+from ncserver.base.modman import ModuleManager
+from ncserver.config import ConfigManager
+
+
+class Server:
+    """The NETCONF server component."""
+
+    def __init__(self, port=830):
+        """Create the NETCONF server.
+
+        :param int port:
+        The port number to listen on.  Typically 830.
+        """
+        self.config = ConfigManager()
+        self.auth = SSHAuthorizedKeysController(
+                users=self.config.get_list('server', 'users')
+        )
+
+        self.debug = self.config.get('server', 'debug')
+        if self.debug:
+            logging.basicConfig(level=logging.DEBUG)
+        else:
+            logging.basicConfig(level=logging.INFO)
+
+        self.server = NetconfSSHServer(
+            self.auth, self, port, self.config.get('server', 'host_key'),
+            self.debug
+        )
+        self.modman = ModuleManager()
+        for module in self.config.get_list('server', 'modules'):
+            self.modman.load_module(module)
+
+    def close(self):
+        """Close all connections."""
+        self.server.close()
+
+    def nc_append_capabilities(self, capabilities):
+        """List all capabilities of this NETCONF server."""
+        for module in self.modman.modules.values():
+            util.subelm(capabilities, 'capability').text = module.M_NS
+
+    def rpc_get(self, session, rpc, filter_or_none):  # pylint: disable=W0613
+        """Handle the <get/> RPC."""
+        root = util.elm('nc:data')
+        self.modman.collect_running(root)
+        self.modman.collect_operational(root)
+
+        return util.filter_results(rpc, root, filter_or_none, self.debug)
+
+    # pylint: disable=W0613
+    def rpc_get_config(self, session, rpc, source, filter_or_none):
+        """Handle the <get-config/> RPC."""
+        root = util.elm('nc:data')
+        self.modman.collect_running(root)
+
+        return util.filter_results(rpc, root, filter_or_none, self.debug)
+
+if __name__ == "__main__":
+    s = Server()
+    try:
+        s.server.join()
+    except KeyboardInterrupt:
+        s.close()
diff --git a/requirements.txt b/requirements.txt
index 959bb53..57d28ca 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,3 @@
 netconf>=2.1.0
+taillight
+PyYAML
-- 
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