diff options
Diffstat (limited to 'python')
| -rw-r--r-- | python/vyos/migrate.py | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/python/vyos/migrate.py b/python/vyos/migrate.py new file mode 100644 index 000000000..9d1613676 --- /dev/null +++ b/python/vyos/migrate.py @@ -0,0 +1,283 @@ +# Copyright 2019-2024 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/>. + +import os +import re +import json +import logging +from pathlib import Path +from grp import getgrnam + +from vyos.component_version import VersionInfo +from vyos.component_version import version_info_from_system +from vyos.component_version import version_info_from_file +from vyos.component_version import version_info_copy +from vyos.component_version import version_info_prune_component +from vyos.compose_config import ComposeConfig +from vyos.compose_config import ComposeConfigError +from vyos.configtree import ConfigTree +from vyos.defaults import directories as default_dir +from vyos.defaults import component_version_json + + +log_file = Path(default_dir['config']).joinpath('vyos-migrate.log') + +class ConfigMigrateError(Exception): + """Raised on error in config migration.""" + +class ConfigMigrate: + # pylint: disable=too-many-instance-attributes + # the number is reasonable in this case + def __init__(self, config_file: str, force=False, + output_file: str = None, checkpoint_file: str = None): + self.config_file: str = config_file + self.force: bool = force + self.system_version: VersionInfo = version_info_from_system() + self.file_version: VersionInfo = version_info_from_file(self.config_file) + self.compose = None + self.output_file = output_file + self.checkpoint_file = checkpoint_file + self.logger = None + self.config_modified = True + + if self.file_version is None: + raise ConfigMigrateError(f'failed to read config file {self.config_file}') + + def migration_needed(self) -> bool: + return self.system_version.component != self.file_version.component + + def release_update_needed(self) -> bool: + return self.system_version.release != self.file_version.release + + def syntax_update_needed(self) -> bool: + return self.system_version.vintage != self.file_version.vintage + + def update_release(self): + """ + Update config file release version. + """ + self.file_version.update_release(self.system_version.release) + + def update_syntax(self): + """ + Update config file syntax. + """ + self.file_version.update_syntax() + + @staticmethod + def normalize_config_body(version_info: VersionInfo): + """ + This is an interim workaround for the cosmetic issue of node + ordering when composing operations on the internal config_tree: + ordering is performed on parsing, hence was maintained in the old + system which would parse/write on each application of a migration + script (~200). Here, we will take the cost of one extra parsing to + reorder before save, for easier review. + """ + if not version_info.config_body_is_none(): + ct = ConfigTree(version_info.config_body) + version_info.update_config_body(ct.to_string()) + + def write_config(self): + if self.output_file is not None: + config_file = self.output_file + else: + config_file = self.config_file + + try: + self.file_version.write(config_file) + except ValueError as e: + raise ConfigMigrateError(f'failed to write {config_file}: {e}') from e + + def init_logger(self): + self.logger = logging.getLogger(__name__) + self.logger.setLevel(logging.DEBUG) + + fh = ConfigMigrate.group_perm_file_handler(log_file, + group='vyattacfg', + mode='w') + fh.setLevel(logging.INFO) + fh_formatter = logging.Formatter('%(message)s') + fh.setFormatter(fh_formatter) + self.logger.addHandler(fh) + ch = logging.StreamHandler() + ch.setLevel(logging.WARNING) + ch_formatter = logging.Formatter('%(name)s - %(levelname)s - %(message)s') + ch.setFormatter(ch_formatter) + self.logger.addHandler(ch) + + @staticmethod + def group_perm_file_handler(filename, group=None, mode='a'): + # pylint: disable=consider-using-with + if group is None: + return logging.FileHandler(filename, mode) + gid = getgrnam(group).gr_gid + if not os.path.exists(filename): + open(filename, 'a').close() + os.chown(filename, -1, gid) + os.chmod(filename, 0o664) + return logging.FileHandler(filename, mode) + + @staticmethod + def sort_function(): + """ + Define sort function for migration files as tuples (n, m) for file + n-to-m. + """ + numbers = re.compile(r'(\d+)') + def func(p: Path): + parts = numbers.split(p.stem) + return list(map(int, parts[1::2])) + return func + + @staticmethod + def file_ext(file_path: Path) -> str: + """ + Return an identifier from file name for checkpoint file extension. + """ + return f'{file_path.parent.stem}_{file_path.stem}' + + def run_migration_scripts(self): + """ + Call migration files iteratively. + """ + os.environ['VYOS_MIGRATION'] = '1' + + self.init_logger() + self.logger.info("List of applied migration modules:") + + components = list(self.system_version.component) + components.sort() + + # T4382: 'bgp' needs to follow 'quagga': + if 'bgp' in components and 'quagga' in components: + components.insert(components.index('quagga'), + components.pop(components.index('bgp'))) + + revision: VersionInfo = version_info_copy(self.file_version) + # prune retired, for example, zone-policy + version_info_prune_component(revision, self.system_version) + + migrate_dir = Path(default_dir['migrate']) + sort_func = ConfigMigrate.sort_function() + + for key in components: + p = migrate_dir.joinpath(key) + script_list = list(p.glob('*-to-*')) + script_list = sorted(script_list, key=sort_func) + + if not self.file_version.component_is_none() and not self.force: + start = self.file_version.component.get(key, 0) + script_list = list(filter(lambda x, st=start: sort_func(x)[0] >= st, + script_list)) + + if not script_list: # no applicable migration scripts + revision.update_component(key, self.system_version.component[key]) + continue + + for file in script_list: + f = file.as_posix() + self.logger.info(f'applying {f}') + try: + self.compose.apply_file(f, func_name='migrate') + except ComposeConfigError as e: + self.logger.error(e) + if self.checkpoint_file: + check = f'{self.checkpoint_file}_{ConfigMigrate.file_ext(file)}' + revision.update_config_body(self.compose.to_string()) + ConfigMigrate.normalize_config_body(revision) + revision.write(check) + break + else: + revision.update_component(key, sort_func(file)[1]) + + revision.update_config_body(self.compose.to_string()) + ConfigMigrate.normalize_config_body(revision) + self.file_version = version_info_copy(revision) + + if revision.component != self.system_version.component: + raise ConfigMigrateError(f'incomplete migration: check {log_file} for error') + + del os.environ['VYOS_MIGRATION'] + + def save_json_record(self): + """ + Write component versions to a json file + """ + version_file = component_version_json + + try: + with open(version_file, 'w') as f: + f.write(json.dumps(self.system_version.component, + indent=2, sort_keys=True)) + except OSError: + pass + + def load_config(self): + """ + Instantiate a ComposeConfig object with the config string. + """ + + self.compose = ComposeConfig(self.file_version.config_body, self.checkpoint_file) + + def run(self): + """ + If migration needed, run migration scripts and update config file. + If only release version update needed, update release version. + """ + # save system component versions in json file for reference + self.save_json_record() + + if not self.migration_needed(): + if self.release_update_needed(): + self.update_release() + self.write_config() + else: + self.config_modified = False + return + + if self.syntax_update_needed(): + self.update_syntax() + self.write_config() + + self.load_config() + + self.run_migration_scripts() + + self.update_release() + self.write_config() + + def run_script(self, test_script: str): + """ + Run a single migration script. For testing this simply provides the + body for loading and writing the result; the component string is not + updated. + """ + + self.load_config() + self.init_logger() + + os.environ['VYOS_MIGRATION'] = '1' + + try: + self.compose.apply_file(test_script, func_name='migrate') + except ComposeConfigError as e: + self.logger.error(f'config-migration error in {test_script}: {e}') + else: + self.file_version.update_config_body(self.compose.to_string()) + + del os.environ['VYOS_MIGRATION'] + + self.write_config() |