diff options
Diffstat (limited to 'python/vyos')
| -rw-r--r-- | python/vyos/config.py | 224 |
1 files changed, 110 insertions, 114 deletions
diff --git a/python/vyos/config.py b/python/vyos/config.py index c9c73b971..d70093531 100644 --- a/python/vyos/config.py +++ b/python/vyos/config.py @@ -1,4 +1,4 @@ -# Copyright 2017 VyOS maintainers and contributors <maintainers@vyos.io> +# Copyright 2017, 2019 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 @@ -17,7 +17,7 @@ A library for reading VyOS running config data. This library is used internally by all config scripts of VyOS, -but its API should be considered stable and it is safe to use +but its API should be considered stable and safe to use in user scripts. Note that this module will not work outside VyOS. @@ -43,8 +43,8 @@ For example, under "system", the names of all valid child nodes are predefined To the contrary, children of the "system task-scheduler task" node can have arbitrary names. Such nodes are called *tag nodes*. This terminology is confusing but we keep using it for lack -of a better word. The knowledge of whether in "task Foo" the "tag" is "task" or "Foo" is lost -in time, luckily, the distinction is irrelevant in practice. +of a better word. No one remembers if the "tag" in "task Foo" is "task" or "Foo", +but the distinction is irrelevant in practice. Configuration modes ################### @@ -53,21 +53,20 @@ VyOS has two distinct modes: operational mode and configuration mode. When a use the CLI is in the operational mode. In this mode, only the running (effective) config is accessible for reading. When a user enters the "configure" command, a configuration session is setup. Every config session -has its *proposed* config built on top of the current running config. When changes are commited, if commit succeeds, +has its *proposed* (or *session*) config built on top of the current running config. When changes are commited, if commit succeeds, the proposed config is merged into the running config. -For this reason, this library has two sets of functions. The base versions, such as ``exists`` or ``return_value`` -are only usable in configuration mode. They take all nodes into account, in both proposed and running configs. -Configuration scripts require access to uncommited changes for obvious reasons. Configuration mode completion helpers -should also use these functions because not having nodes you've just created in completion is annoying. +In configuration mode, "base" functions like `exists`, `return_value` return values from the session config, +while functions prefixed "effective" return values from the running config. + +In operational mode, all functions return values from the running config. -However, in operational mode, only the running config is available. Currently, you need to use special functions -for reading it from operational mode scripts, they can be distinguished by the word "effective" in their names. -In the future base versions may be made to detect if they are called from a config session or not. """ -import subprocess import re +import subprocess + +import vyos.configtree class VyOSError(Exception): @@ -89,17 +88,42 @@ class Config(object): """ def __init__(self, session_env=None): self._cli_shell_api = "/bin/cli-shell-api" - self._level = "" + 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 + # (if config system is initialized at all). + running_config_text = self._run([self._cli_shell_api, '--show-active-only', '--show-show-defaults', 'showConfig']) + + # Session config ("active") only exists in conf mode. + # Trying to obtain it from op mode will cause a fatal cli-shell-api error. + # If that happens, we assume that a script is running from op mode and use the running config + # for the "session config" variable as well. + try: + session_config_text = self._run([self._cli_shell_api, '--show-working-only', '--show-show-defaults', 'showConfig']) + except VyOSError: + session_config_text = running_config_text + + self._session_config = vyos.configtree.ConfigTree(session_config_text) + self._running_config = vyos.configtree.ConfigTree(running_config_text) + def _make_command(self, op, path): args = path.split() cmd = [self._cli_shell_api, op] + args return cmd + def _make_path(self, path): + # Backwards-compatibility stuff: original implementation used string paths + # libvyosconfig paths are lists, but since node names cannot contain whitespace, + # splitting at whitespace is reasonably safe. + # It may cause problems with exists() when it's used for checking values, + # since values may contain whitespace. + path = re.split(r'\s*', path) + return (self._level + path) + def _run(self, cmd): if self.__session_env: p = subprocess.Popen(cmd, stdout=subprocess.PIPE, env=self.__session_env) @@ -126,7 +150,7 @@ class Config(object): # 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 - self._level = path + " " + self._level = re.split(r'\s*', path) def get_level(self): """ @@ -135,7 +159,7 @@ class Config(object): Returns: str: current edit level """ - return(self._level.strip()) + return(self._level) def exists(self, path): """ @@ -148,11 +172,20 @@ class Config(object): This function cannot be used outside a configuration sessions. In operational mode scripts, use ``exists_effective``. """ - try: - self._run(self._make_command('exists', self._level + path)) + if self._session_config.exists(self._make_path(path)): return True - except VyOSError: - return False + else: + # libvyosconfig exists() works only for _nodes_, not _values_ + # libvyattacfg one also worked for values, so we emulate that case here + path = re.split(r'\s*', path) + path_without_value = path[:-1] + path_str = " ".join(path_without_value) + try: + value = self._session_config.return_value(self._make_path(path_str)) + return (value == path[-1]) + except vyos.configtree.ConfigTreeError: + # node doesn't exist at all + return False def session_changed(self): """ @@ -203,7 +236,8 @@ class Config(object): It also returns False if node doesn't exist. """ try: - self._run(self._make_command('isMulti', self._level + path)) + path = " ".join(self._level) + " " + path + self._run(self._make_command('isMulti', path)) return True except VyOSError: return False @@ -220,7 +254,8 @@ class Config(object): It also returns False if node doesn't exist. """ try: - self._run(self._make_command('isTag', self._level + path)) + path = " ".join(self._level) + " " + path + self._run(self._make_command('isTag', path)) return True except VyOSError: return False @@ -237,7 +272,8 @@ class Config(object): It also returns False if node doesn't exist. """ try: - self._run(self._make_command('isLeaf', self._level + path)) + path = " ".join(self._level) + " " + path + self._run(self._make_command('isLeaf', path)) return True except VyOSError: return False @@ -254,9 +290,6 @@ class Config(object): str: Node value, if it has any None: if node is valueless *or* if it doesn't exist - Raises: - VyOSError: if node is not a single-value leaf node - Note: Due to the issue with treatment of valueless nodes by this function, valueless nodes should be checked with ``exists`` instead. @@ -264,17 +297,15 @@ class Config(object): This function cannot be used outside a configuration session. In operational mode scripts, use ``return_effective_value``. """ - full_path = self._level + path - if self.is_multi(path): - raise VyOSError("Cannot use return_value on multi node: {0}".format(full_path)) - elif not self.is_leaf(path): - raise VyOSError("Cannot use return_value on non-leaf node: {0}".format(full_path)) + try: + value = self._session_config.return_value(self._make_path(path)) + except vyos.configtree.ConfigTreeError: + value = None + + if not value: + return(default) else: - try: - out = self._run(self._make_command('returnValue', full_path)) - return out - except VyOSError: - return(default) + return(value) def return_values(self, path, default=[]): """ @@ -285,27 +316,21 @@ class Config(object): Returns: str list: Node values, if it has any - None: if node does not exist - - Raises: - VyOSError: if node is not a multi-value leaf node + []: if node does not exist Note: This function cannot be used outside a configuration session. In operational mode scripts, use ``return_effective_values``. """ - full_path = self._level + path - if not self.is_multi(path): - raise VyOSError("Cannot use return_values on non-multi node: {0}".format(full_path)) - elif not self.is_leaf(path): - raise VyOSError("Cannot use return_values on non-leaf node: {0}".format(full_path)) + try: + values = self._session_config.return_values(self._make_path(path)) + except vyos.configtree.ConfigTreeError: + values = [] + + if not values: + return(default) else: - try: - out = self._run(self._make_command('returnValues', full_path)) - values = re.findall(r"\'(.*?)\'", out) - return values - except VyOSError: - return(default) + return(values) def list_nodes(self, path, default=[]): """ @@ -317,26 +342,16 @@ class Config(object): Returns: string list: child node names - Raises: - VyOSError: if the node is not a tag node - - Note: - There is no way to list all children of a non-tag node in - the current config backend. - - This function cannot be used outside a configuration session. - In operational mode scripts, use ``list_effective_nodes``. """ - full_path = self._level + path - if self.is_tag(path): - try: - out = self._run(self._make_command('listNodes', full_path)) - values = re.findall(r"\'(.*?)\'", out) - return values - except VyOSError: - return(default) + try: + nodes = self._session_config.list_nodes(self._make_path(path)) + except vyos.configtree.ConfigTreeError: + nodes = [] + + if not nodes: + return(default) else: - raise VyOSError("Cannot use list_nodes on a non-tag node: {0}".format(full_path)) + return(nodes) def exists_effective(self, path): """ @@ -352,11 +367,7 @@ class Config(object): This function is safe to use in operational mode. In configuration mode, it ignores uncommited changes. """ - try: - self._run(self._make_command('existsEffective', self._level + path)) - return True - except VyOSError: - return False + return(self._running_config.exists(self._make_path(path))) def return_effective_value(self, path, default=None): """ @@ -368,21 +379,17 @@ class Config(object): Returns: str: Node value - - Raises: - VyOSError: if node is not a multi-value leaf node """ - full_path = self._level + path - if self.is_multi(path): - raise VyOSError("Cannot use return_effective_value on multi node: {0}".format(full_path)) - elif not self.is_leaf(path): - raise VyOSError("Cannot use return_effective_value on non-leaf node: {0}".format(full_path)) + try: + value = self._running_config.return_value(self._make_path(path)) + except vyos.configtree.ConfigTreeError: + value = None + + if not value: + return(default) else: - try: - out = self._run(self._make_command('returnEffectiveValue', full_path)) - return out - except VyOSError: - return(default) + return(value) + def return_effective_values(self, path, default=[]): """ @@ -393,22 +400,16 @@ class Config(object): Returns: str list: A list of values - - Raises: - VyOSError: if node is not a multi-value leaf node """ - full_path = self._level + path - if not self.is_multi(path): - raise VyOSError("Cannot use return_effective_values on non-multi node: {0}".format(full_path)) - elif not self.is_leaf(path): - raise VyOSError("Cannot use return_effective_values on non-leaf node: {0}".format(full_path)) + try: + values = self._running_config.return_values(self._make_path(path)) + except vyos.configtree.ConfigTreeError: + values = [] + + if not values: + return(default) else: - try: - out = self._run(self._make_command('returnEffectiveValues', full_path)) - values = re.findall(r"\'(.*?)\'", out) - return values - except VyOSError: - return(default) + return(values) def list_effective_nodes(self, path, default=[]): """ @@ -422,18 +423,13 @@ class Config(object): Raises: VyOSError: if the node is not a tag node - - Note: - There is no way to list all children of a non-tag node in - the current config backend. """ - full_path = self._level + path - if self.is_tag(path): - try: - out = self._run(self._make_command('listEffectiveNodes', full_path)) - values = out.split() - return list(map(lambda x: re.sub(r'^\'(.*)\'$', r'\1',x), values)) - except VyOSError: - return(default) + try: + nodes = self._running_config.list_nodes(self._make_path(path)) + except vyos.configtree.ConfigTreeError: + nodes = [] + + if not nodes: + return(default) else: - raise VyOSError("Cannot use list_effective_nodes on a non-tag node: {0}".format(full_path)) + return(nodes) |