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| -rw-r--r-- | python/vyos/configsource.py | 318 |
1 files changed, 318 insertions, 0 deletions
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)}") |