T1432: initial implementation of the config write API.

1 files changed, 94 insertions, 0 deletions

diff --git a/python/vyos/configsession.py b/python/vyos/configsession.py
new file mode 100644
index 000000000..4e9d30fa7
--- /dev/null
+++ b/python/vyos/configsession.py
@@ -0,0 +1,94 @@
+# configsession -- the write API for the VyOS running config
+# Copyright (C) 2019 VyOS maintainers and contributors
+#
+# This library is free software; you can redistribute it and/or modify it under the terms of
+# the GNU Lesser General Public License as published by the Free Software Foundation;
+# either version 2.1 of the License, or (at your option) any later version.
+#
+# This library 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License along with this library;
+# if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
+
+import os
+import re
+import subprocess
+
+CLI_SHELL_API = '/bin/cli-shell-api'
+SET = '/opt/vyatta/sbin/my_set'
+DELETE = '/opt/vyatta/sbin/my_delete'
+COMMENT = '/opt/vyatta/sbin/my_comment'
+COMMIT = '/opt/vyatta/sbin/my_commit'
+
+APP = "vyos-api"
+
+
+class ConfigSessionError(Exception):
+    pass
+
+
+class ConfigSession(object):
+    """
+    The write API of VyOS.
+    """
+    def __init__(self, session_id, app=APP):
+        """
+         Creates a new config session.
+
+         Args:
+              session_id (str): Session identifier
+              app (str): Application name, purely informational
+
+        Note:
+            The session identifier MUST be globally unique within the system.
+            The best practice is to only have one ConfigSession object per process
+            and used the PID for the session identifier.
+        """
+
+        env_str = subprocess.check_output([CLI_SHELL_API, 'getSessionEnv', str(session_id)])
+
+        # Extract actual variables from the chunk of shell it outputs
+        # XXX: it's better to extend cli-shell-api to provide easily readable output
+        env_list = re.findall(r'([A-Z_]+)=([^;\s]+)', env_str.decode())
+
+        session_env = os.environ
+        for k, v in env_list:
+            session_env[k] = v
+
+        self.__session_env = session_env
+        self.__session_env["COMMIT_VIA"] = app
+
+        self.__run_command([CLI_SHELL_API, 'setupSession'])
+
+    def __run_command(self, cmd_list):
+        p = subprocess.Popen(cmd_list, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, env=self.__session_env)
+        result = p.wait()
+        output = p.stdout.read().decode()
+        if result != 0:
+            raise VyOSAPIError(output)
+
+    def set(self, path, value=None):
+        if not value:
+            value = []
+        else:
+            value = [value]
+        self.__run_command([SET] + path + value)
+
+    def delete(self, path, value=None):
+        if not value:
+            value = []
+        else:
+            value = [value]
+        self.__run_command([DELETE] + path + value)
+
+    def comment(self, path, value=None):
+        if not value:
+            value = [""]
+        else:
+            value = [value]
+        self.__run_command([COMMENT] + path + value)
+
+    def commit(self):
+        self.__run_command([COMMIT])