From 142495eae746a689473a29fa4854eb713d42e59e Mon Sep 17 00:00:00 2001
From: John Estabrook <jestabro@vyos.io>
Date: Wed, 22 Jul 2020 13:14:54 -0500
Subject: config: T2707: add ConfigSource classes for alternative init data
---
python/vyos/configsource.py | 318 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 318 insertions(+)
create mode 100644 python/vyos/configsource.py
(limited to 'python')
diff --git a/python/vyos/configsource.py b/python/vyos/configsource.py
new file mode 100644
index 000000000..50222e385
--- /dev/null
+++ b/python/vyos/configsource.py
@@ -0,0 +1,318 @@
+
+# Copyright 2020 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# 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, see <http://www.gnu.org/licenses/>.
+
+import os
+import re
+import subprocess
+
+from vyos.configtree import ConfigTree
+
+class VyOSError(Exception):
+ """
+ Raised on config access errors.
+ """
+ pass
+
+class ConfigSourceError(Exception):
+ '''
+ Raised on error in ConfigSource subclass init.
+ '''
+ pass
+
+class ConfigSource:
+ def __init__(self):
+ self._running_config: ConfigTree = None
+ self._session_config: ConfigTree = None
+
+ def get_configtree_tuple(self):
+ return self._running_config, self._session_config
+
+ def session_changed(self):
+ """
+ Returns:
+ True if the config session has uncommited changes, False otherwise.
+ """
+ raise NotImplementedError(f"function not available for {type(self)}")
+
+ def in_session(self):
+ """
+ Returns:
+ True if called from a configuration session, False otherwise.
+ """
+ raise NotImplementedError(f"function not available for {type(self)}")
+
+ def show_config(self, path=[], default=None, effective=False):
+ """
+ Args:
+ path (str|list): Configuration tree path, or empty
+ default (str): Default value to return
+
+ Returns:
+ str: working configuration
+ """
+ raise NotImplementedError(f"function not available for {type(self)}")
+
+ def is_multi(self, path):
+ """
+ Args:
+ path (str): Configuration tree path
+
+ Returns:
+ True if a node can have multiple values, False otherwise.
+
+ Note:
+ It also returns False if node doesn't exist.
+ """
+ raise NotImplementedError(f"function not available for {type(self)}")
+
+ def is_tag(self, path):
+ """
+ Args:
+ path (str): Configuration tree path
+
+ Returns:
+ True if a node is a tag node, False otherwise.
+
+ Note:
+ It also returns False if node doesn't exist.
+ """
+ raise NotImplementedError(f"function not available for {type(self)}")
+
+ def is_leaf(self, path):
+ """
+ Args:
+ path (str): Configuration tree path
+
+ Returns:
+ True if a node is a leaf node, False otherwise.
+
+ Note:
+ It also returns False if node doesn't exist.
+ """
+ raise NotImplementedError(f"function not available for {type(self)}")
+
+class ConfigSourceSession(ConfigSource):
+ def __init__(self, session_env=None):
+ super().__init__()
+ self._cli_shell_api = "/bin/cli-shell-api"
+ self._level = []
+ if session_env:
+ self.__session_env = session_env
+ else:
+ self.__session_env = None
+
+ # Running config can be obtained either from op or conf mode, it always succeeds
+ # once the config system is initialized during boot;
+ # before initialization, set to empty string
+ if os.path.isfile('/tmp/vyos-config-status'):
+ try:
+ running_config_text = self._run([self._cli_shell_api, '--show-active-only', '--show-show-defaults', '--show-ignore-edit', 'showConfig'])
+ except VyOSError:
+ running_config_text = ''
+ else:
+ running_config_text = ''
+
+ # Session config ("active") only exists in conf mode.
+ # In op mode, we'll just use the same running config for both active and session configs.
+ if self.in_session():
+ try:
+ session_config_text = self._run([self._cli_shell_api, '--show-working-only', '--show-show-defaults', '--show-ignore-edit', 'showConfig'])
+ except VyOSError:
+ session_config_text = ''
+ else:
+ session_config_text = running_config_text
+
+ if running_config_text:
+ self._running_config = ConfigTree(running_config_text)
+ else:
+ self._running_config = None
+
+ if session_config_text:
+ self._session_config = ConfigTree(session_config_text)
+ else:
+ self._session_config = None
+
+ def _make_command(self, op, path):
+ args = path.split()
+ cmd = [self._cli_shell_api, op] + args
+ return cmd
+
+ def _run(self, cmd):
+ if self.__session_env:
+ p = subprocess.Popen(cmd, stdout=subprocess.PIPE, env=self.__session_env)
+ else:
+ p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+ out = p.stdout.read()
+ p.wait()
+ p.communicate()
+ if p.returncode != 0:
+ raise VyOSError()
+ else:
+ return out.decode('ascii')
+
+ def set_level(self, path):
+ """
+ Set the *edit level*, that is, a relative config tree path.
+ Once set, all operations will be relative to this path,
+ for example, after ``set_level("system")``, calling
+ ``exists("name-server")`` is equivalent to calling
+ ``exists("system name-server"`` without ``set_level``.
+
+ Args:
+ path (str|list): relative config path
+ """
+ # Make sure there's always a space between default path (level)
+ # and path supplied as method argument
+ # XXX: for small strings in-place concatenation is not a problem
+ if isinstance(path, str):
+ if path:
+ self._level = re.split(r'\s+', path)
+ else:
+ self._level = []
+ elif isinstance(path, list):
+ self._level = path.copy()
+ else:
+ raise TypeError("Level path must be either a whitespace-separated string or a list")
+
+ def session_changed(self):
+ """
+ Returns:
+ True if the config session has uncommited changes, False otherwise.
+ """
+ try:
+ self._run(self._make_command('sessionChanged', ''))
+ return True
+ except VyOSError:
+ return False
+
+ def in_session(self):
+ """
+ Returns:
+ True if called from a configuration session, False otherwise.
+ """
+ try:
+ self._run(self._make_command('inSession', ''))
+ return True
+ except VyOSError:
+ return False
+
+ def show_config(self, path=[], default=None, effective=False):
+ """
+ Args:
+ path (str|list): Configuration tree path, or empty
+ default (str): Default value to return
+
+ Returns:
+ str: working configuration
+ """
+
+ # show_config should be independent of CLI edit level.
+ # Set the CLI edit environment to the top level, and
+ # restore original on exit.
+ save_env = self.__session_env
+
+ env_str = self._run(self._make_command('getEditResetEnv', ''))
+ env_list = re.findall(r'([A-Z_]+)=\'([^;\s]+)\'', env_str)
+ root_env = os.environ
+ for k, v in env_list:
+ root_env[k] = v
+
+ self.__session_env = root_env
+
+ # FIXUP: by default, showConfig will give you a diff
+ # if there are uncommitted changes.
+ # The config parser obviously cannot work with diffs,
+ # so we need to supress diff production using appropriate
+ # options for getting either running (active)
+ # or proposed (working) config.
+ if effective:
+ path = ['--show-active-only'] + path
+ else:
+ path = ['--show-working-only'] + path
+
+ if isinstance(path, list):
+ path = " ".join(path)
+ try:
+ out = self._run(self._make_command('showConfig', path))
+ self.__session_env = save_env
+ return out
+ except VyOSError:
+ self.__session_env = save_env
+ return(default)
+
+ def is_multi(self, path):
+ """
+ Args:
+ path (str): Configuration tree path
+
+ Returns:
+ True if a node can have multiple values, False otherwise.
+
+ Note:
+ It also returns False if node doesn't exist.
+ """
+ try:
+ path = " ".join(self._level) + " " + path
+ self._run(self._make_command('isMulti', path))
+ return True
+ except VyOSError:
+ return False
+
+ def is_tag(self, path):
+ """
+ Args:
+ path (str): Configuration tree path
+
+ Returns:
+ True if a node is a tag node, False otherwise.
+
+ Note:
+ It also returns False if node doesn't exist.
+ """
+ try:
+ path = " ".join(self._level) + " " + path
+ self._run(self._make_command('isTag', path))
+ return True
+ except VyOSError:
+ return False
+
+ def is_leaf(self, path):
+ """
+ Args:
+ path (str): Configuration tree path
+
+ Returns:
+ True if a node is a leaf node, False otherwise.
+
+ Note:
+ It also returns False if node doesn't exist.
+ """
+ try:
+ path = " ".join(self._level) + " " + path
+ self._run(self._make_command('isLeaf', path))
+ return True
+ except VyOSError:
+ return False
+
+class ConfigSourceString(ConfigSource):
+ def __init__(self, running_config_text=None, session_config_text=None):
+ super().__init__()
+
+ try:
+ self._running_config = ConfigTree(running_config_text) if running_config_text else None
+ self._session_config = ConfigTree(session_config_text) if session_config_text else None
+ except ValueError:
+ raise ConfigSourceError(f"Init error in {type(self)}")
--
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