1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
# Copyright 2023-2024 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/>.
"""This module abstracts the loading of a config file into the running
config. It provides several varieties of loading a config file, from the
legacy version to the developing versions, as a means of offering
alternatives for competing use cases, and a base for profiling the
performance of each.
"""
import sys
from pathlib import Path
from tempfile import NamedTemporaryFile
from typing import Union, Literal, TypeAlias, get_type_hints, get_args
from vyos.config import Config
from vyos.configtree import ConfigTree, DiffTree
from vyos.configsource import ConfigSourceSession, VyOSError
from vyos.migrate import ConfigMigrate, ConfigMigrateError
from vyos.utils.process import popen, DEVNULL
Variety: TypeAlias = Literal['explicit', 'batch', 'tree', 'legacy']
ConfigObj: TypeAlias = Union[str, ConfigTree]
thismod = sys.modules[__name__]
class LoadConfigError(Exception):
"""Raised when an error occurs loading a config file.
"""
# utility functions
def get_running_config(config: Config) -> ConfigTree:
return config.get_config_tree(effective=True)
def get_proposed_config(config_file: str = None) -> ConfigTree:
config_str = Path(config_file).read_text()
return ConfigTree(config_str)
def check_session(strict: bool, switch: Variety) -> None:
"""Check if we are in a config session, with no uncommitted changes, if
strict. This is not needed for legacy load, as these checks are
implicit.
"""
if switch == 'legacy':
return
context = ConfigSourceSession()
if not context.in_session():
raise LoadConfigError('not in a config session')
if strict and context.session_changed():
raise LoadConfigError('commit or discard changes before loading config')
# methods to call for each variety
# explicit
def diff_to_commands(ctree: ConfigTree, ntree: ConfigTree) -> list:
"""Calculate the diff between the current and proposed config."""
# Calculate the diff between the current and new config tree
commands = DiffTree(ctree, ntree).to_commands()
# on an empty set of 'add' or 'delete' commands, to_commands
# returns '\n'; prune below
command_list = commands.splitlines()
command_list = [c for c in command_list if c]
return command_list
def set_commands(cmds: list) -> None:
"""Set commands in the config session."""
if not cmds:
print('no commands to set')
return
error_out = []
for op in cmds:
out, rc = popen(f'/opt/vyatta/sbin/my_{op}', shell=True, stderr=DEVNULL)
if rc != 0:
error_out.append(out)
continue
if error_out:
out = '\n'.join(error_out)
raise LoadConfigError(out)
# legacy
class LoadConfig(ConfigSourceSession):
"""A subclass for calling 'loadFile'.
"""
def load_config(self, file_name):
return self._run(['/bin/cli-shell-api','loadFile', file_name])
# end methods to call for each variety
def migrate(config_obj: ConfigObj) -> ConfigObj:
"""Migrate a config object to the current version.
"""
if isinstance(config_obj, ConfigTree):
config_file = NamedTemporaryFile(delete=False).name
Path(config_file).write_text(config_obj.to_string())
else:
config_file = config_obj
config_migrate = ConfigMigrate(config_file)
try:
config_migrate.run()
except ConfigMigrateError as e:
raise LoadConfigError(e) from e
else:
if isinstance(config_obj, ConfigTree):
return ConfigTree(Path(config_file).read_text())
return config_file
finally:
if isinstance(config_obj, ConfigTree):
Path(config_file).unlink()
def load_explicit(config_obj: ConfigObj):
"""Explicit load from file or configtree.
"""
config = Config()
ctree = get_running_config(config)
if isinstance(config_obj, ConfigTree):
ntree = config_obj
else:
ntree = get_proposed_config(config_obj)
# Calculate the diff between the current and proposed config
cmds = diff_to_commands(ctree, ntree)
# Set the commands in the config session
set_commands(cmds)
def load_batch(config_obj: ConfigObj):
# requires legacy backend patch
raise NotImplementedError('batch loading not implemented')
def load_tree(config_obj: ConfigObj):
# requires vyconf backend patch
raise NotImplementedError('tree loading not implemented')
def load_legacy(config_obj: ConfigObj):
"""Legacy load from file or configtree.
"""
if isinstance(config_obj, ConfigTree):
config_file = NamedTemporaryFile(delete=False).name
Path(config_file).write_text(config_obj.to_string())
else:
config_file = config_obj
config = LoadConfig()
try:
config.load_config(config_file)
except VyOSError as e:
raise LoadConfigError(e) from e
finally:
if isinstance(config_obj, ConfigTree):
Path(config_file).unlink()
def load(config_obj: ConfigObj, strict: bool = True,
switch: Variety = 'legacy'):
type_hints = get_type_hints(load)
switch_choice = get_args(type_hints['switch'])
if switch not in switch_choice:
raise ValueError(f'invalid switch: {switch}')
check_session(strict, switch)
config_obj = migrate(config_obj)
func = getattr(thismod, f'load_{switch}')
func(config_obj)
|
