Add module to load the configuration

"server.conf.in" is provided as an example file with a description of
all the configurations. Some descriptions were copied from
https://github.com/strukturag/nextcloud-spreed-signaling/blob/v1.0.0/server.conf.in,
which is also licensed under the GNU AGPLv3.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

3 files changed, 258 insertions, 0 deletions

diff --git a/recording/server.conf.in b/recording/server.conf.in
new file mode 100644
index 000000000..111916235
--- /dev/null
+++ b/recording/server.conf.in
@@ -0,0 +1,67 @@
+[logs]
+# Log level based on numeric values of Python logging levels:
+# - Critical: 50
+# - Error:    40
+# - Warning:  30
+# - Info:     20
+# - Debug:    10
+# - Not set:   0
+#level = 20
+
+[http]
+# IP and port to listen on for HTTP requests.
+#listen = 127.0.0.1:8000
+
+[backend]
+# Allow any hostname as backend endpoint. This is extremely insecure and should
+# only be used during development.
+#allowall = false
+
+# Common shared secret for requests from and to the backend servers if
+# "allowall" is enabled. This must be the same value as configured in the
+# Nextcloud admin ui.
+#secret = the-shared-secret
+
+# Comma-separated list of backend ids allowed to connect.
+#backends = backend-id, another-backend
+
+# If set to "true", certificate validation of backend endpoints will be skipped.
+# This should only be enabled during development, e.g. to work with self-signed
+# certificates.
+# Overridable by backend.
+#skipverify = false
+
+# Maximum allowed size in bytes for messages sent by the backend.
+# Overridable by backend.
+#maxmessagesize = 1024
+
+# Width for recorded videos.
+# Overridable by backend.
+#videowidth = 1920
+
+# Height for recorded videos.
+# Overridable by backend.
+#videoheight = 1080
+
+# Temporary directory used to store recordings until uploaded. It must be
+# writable by the user running the recording server.
+# Overridable by backend.
+#directory = /tmp
+
+# Backend configurations as defined in the "[backend]" section above. The
+# section names must match the ids used in "backends" above.
+#[backend-id]
+# URL of the Nextcloud instance
+#url = https://cloud.domain.invalid
+
+# Shared secret for requests from and to the backend servers. This must be the
+# same value as configured in the Nextcloud admin ui.
+#secret = the-shared-secret
+
+#[another-backend]
+# URL of the Nextcloud instance
+#url = https://cloud.otherdomain.invalid
+
+# Shared secret for requests from and to the backend servers. This must be the
+# same value as configured in the Nextcloud admin ui.
+#secret = the-shared-secret
diff --git a/recording/src/nextcloud/talk/recording/Config.py b/recording/src/nextcloud/talk/recording/Config.py
new file mode 100644
index 000000000..9e177dedb
--- /dev/null
+++ b/recording/src/nextcloud/talk/recording/Config.py
@@ -0,0 +1,160 @@
+#
+# @copyright Copyright (c) 2023, Daniel Calviño Sánchez (danxuliu@gmail.com)
+#
+# @license GNU AGPL version 3 or any later version
+#
+# 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 should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+"""
+Module for getting the configuration.
+
+Other modules are expected to import the shared "config" object, which will be
+loaded with the configuration file at startup.
+"""
+
+import logging
+import os
+
+from configparser import ConfigParser
+
+class Config:
+    def __init__(self):
+        self._logger = logging.getLogger(__name__)
+
+        self._configParser = ConfigParser()
+
+        self._backendIdsByBackendUrl = {}
+
+    def load(self, fileName):
+        fileName = os.path.abspath(fileName)
+
+        if not os.path.exists(fileName):
+            self._logger.warning(f"Configuration file not found: {fileName}")
+        else:
+            self._logger.info(f"Loading {fileName}")
+
+        self._configParser.read(fileName)
+
+        self._loadBackends()
+
+    def _loadBackends(self):
+        self._backendIdsByBackendUrl = {}
+
+        if 'backend' not in self._configParser or 'backends' not in self._configParser['backend']:
+            self._logger.warning(f"No configured backends")
+
+            return
+
+        backendIds = self._configParser.get('backend', 'backends')
+        backendIds = [backendId.strip() for backendId in backendIds.split(',')]
+
+        for backendId in backendIds:
+            if 'url' not in self._configParser[backendId]:
+                self._logger.error(f"Missing 'url' property for backend {backendId}")
+                continue
+
+            if 'secret' not in self._configParser[backendId]:
+                self._logger.error(f"Missing 'secret' property for backend {backendId}")
+                continue
+
+            backendUrl = self._configParser[backendId]['url'].rstrip('/')
+            self._backendIdsByBackendUrl[backendUrl] = backendId
+
+    def getLogLevel(self):
+        """
+        Returns the log level.
+
+        Defaults to INFO (20).
+        """
+        return int(self._configParser.get('logs', 'level', fallback=logging.INFO))
+
+    def getListen(self):
+        """
+        Returns the IP and port to listen on for HTTP requests.
+
+        Defaults to "127.0.0.1:8000".
+        """
+        return self._configParser.get('http', 'listen', fallback='127.0.0.1:8000')
+
+    def getBackendSecret(self, backendUrl):
+        """
+        Returns the shared secret for requests from and to the backend servers.
+
+        Defaults to None.
+        """
+        if self._configParser.get('backend', 'allowall', fallback=None):
+            return self._configParser.get('backend', 'secret')
+
+        backendUrl = backendUrl.rstrip('/')
+        if backendUrl in self._backendIdsByBackendUrl:
+            backendId = self._backendIdsByBackendUrl[backendUrl]
+
+            return self._configParser.get(backendId, 'secret', fallback=None)
+
+        return None
+
+    def getBackendSkipVerify(self, backendUrl):
+        """
+        Returns whether the certificate validation of backend endpoints should
+        be skipped or not.
+
+        Defaults to False.
+        """
+        return self._getBackendValue(backendUrl, 'skipverify', False) == 'true'
+
+    def getBackendMaximumMessageSize(self, backendUrl):
+        """
+        Returns the maximum allowed size in bytes for messages sent by the
+        backend.
+
+        Defaults to 1024.
+        """
+        return int(self._getBackendValue(backendUrl, 'maxmessagesize', 1024))
+
+    def getBackendVideoWidth(self, backendUrl):
+        """
+        Returns the width for recorded videos.
+
+        Defaults to 1920.
+        """
+        return int(self._getBackendValue(backendUrl, 'videowidth', 1920))
+
+    def getBackendVideoHeight(self, backendUrl):
+        """
+        Returns the height for recorded videos.
+
+        Defaults to 1080.
+        """
+        return int(self._getBackendValue(backendUrl, 'videoheight', 1080))
+
+    def getBackendDirectory(self, backendUrl):
+        """
+        Returns the temporary directory used to store recordings until uploaded.
+
+        Defaults to False.
+        """
+        return self._getBackendValue(backendUrl, 'directory', '/tmp')
+
+    def _getBackendValue(self, backendUrl, key, default):
+        backendUrl = backendUrl.rstrip('/')
+        if backendUrl in self._backendIdsByBackendUrl:
+            backendId = self._backendIdsByBackendUrl[backendUrl]
+
+            if self._configParser.get(backendId, key, fallback=None):
+                return self._configParser.get(backendId, key)
+
+        return self._configParser.get('backend', key, fallback=default)
+
+config = Config()
diff --git a/recording/src/nextcloud/talk/recording/__main__.py b/recording/src/nextcloud/talk/recording/__main__.py
new file mode 100644
index 000000000..358fc91bb
--- /dev/null
+++ b/recording/src/nextcloud/talk/recording/__main__.py
@@ -0,0 +1,31 @@
+#
+# @copyright Copyright (c) 2023, Daniel Calviño Sánchez (danxuliu@gmail.com)
+#
+# @license GNU AGPL version 3 or any later version
+#
+# 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 should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import argparse
+import logging
+
+from .Config import config
+
+parser = argparse.ArgumentParser()
+parser.add_argument("-c", "--config", help="path to configuration file", default="server.conf")
+args = parser.parse_args()
+
+config.load(args.config)
+
+logging.basicConfig(level=config.getLogLevel())