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Diffstat (limited to 'python/vyos/migrator.py')
| -rw-r--r-- | python/vyos/migrator.py | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/python/vyos/migrator.py b/python/vyos/migrator.py new file mode 100644 index 000000000..9a5fdef2f --- /dev/null +++ b/python/vyos/migrator.py @@ -0,0 +1,220 @@ +# Copyright 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 +# 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 sys +import os +import subprocess +import vyos.version +import vyos.defaults +import vyos.systemversions as systemversions +import vyos.formatversions as formatversions + +class MigratorError(Exception): + pass + +class Migrator(object): + def __init__(self, config_file, force=False, set_vintage='vyos'): + self._config_file = config_file + self._force = force + self._set_vintage = set_vintage + self._config_file_vintage = None + self._log_file = None + self._changed = False + + def read_config_file_versions(self): + """ + Get component versions from config file footer and set vintage; + return empty dictionary if config string is missing. + """ + cfg_file = self._config_file + component_versions = {} + + cfg_versions = formatversions.read_vyatta_versions(cfg_file) + + if cfg_versions: + self._config_file_vintage = 'vyatta' + component_versions = cfg_versions + + cfg_versions = formatversions.read_vyos_versions(cfg_file) + + if cfg_versions: + self._config_file_vintage = 'vyos' + component_versions = cfg_versions + + return component_versions + + def update_vintage(self): + old_vintage = self._config_file_vintage + + if self._set_vintage: + self._config_file_vintage = self._set_vintage + + if self._config_file_vintage not in ['vyatta', 'vyos']: + raise MigratorError("Unknown vintage.") + + if self._config_file_vintage == old_vintage: + return False + else: + return True + + def open_log_file(self): + """ + Open log file for migration, catching any error. + Note that, on boot, migration takes place before the canonical log + directory is created, hence write to the config file directory. + """ + self._log_file = os.path.join(vyos.defaults.directories['config'], + 'vyos-migrate.log') + # on creation, allow write permission for cfg_group; + # restore original umask on exit + mask = os.umask(0o113) + try: + log = open('{0}'.format(self._log_file), 'w') + log.write("List of executed migration scripts:\n") + except Exception as e: + os.umask(mask) + print("Logging error: {0}".format(e)) + return None + + os.umask(mask) + return log + + def run_migration_scripts(self, config_file_versions, system_versions): + """ + Run migration scripts iteratively, until config file version equals + system component version. + """ + log = self.open_log_file() + + cfg_versions = config_file_versions + sys_versions = system_versions + + sys_keys = list(sys_versions.keys()) + sys_keys.sort() + + rev_versions = {} + + for key in sys_keys: + sys_ver = sys_versions[key] + if key in cfg_versions: + cfg_ver = cfg_versions[key] + else: + cfg_ver = 0 + + migrate_script_dir = os.path.join( + vyos.defaults.directories['migrate'], key) + + while cfg_ver < sys_ver: + next_ver = cfg_ver + 1 + + migrate_script = os.path.join(migrate_script_dir, + '{}-to-{}'.format(cfg_ver, next_ver)) + + try: + subprocess.check_call([migrate_script, + self._config_file]) + except FileNotFoundError: + pass + except Exception as err: + print("\nMigration script error: {0}: {1}." + "".format(migrate_script, err)) + sys.exit(1) + + if log: + try: + log.write('{0}\n'.format(migrate_script)) + except Exception as e: + print("Error writing log: {0}".format(e)) + + cfg_ver = next_ver + + rev_versions[key] = cfg_ver + + if log: + log.close() + + return rev_versions + + def write_config_file_versions(self, cfg_versions): + """ + Write new versions string. + """ + versions_string = formatversions.format_versions_string(cfg_versions) + + os_version_string = vyos.version.get_version() + + if self._config_file_vintage == 'vyatta': + formatversions.write_vyatta_versions_foot(self._config_file, + versions_string, + os_version_string) + + if self._config_file_vintage == 'vyos': + formatversions.write_vyos_versions_foot(self._config_file, + versions_string, + os_version_string) + + def run(self): + """ + Gather component versions from config file and system. + Run migration scripts. + Update vintage ('vyatta' or 'vyos'), if needed. + If changed, remove old versions string from config file, and + write new versions string. + """ + cfg_file = self._config_file + + cfg_versions = self.read_config_file_versions() + if self._force: + # This will force calling all migration scripts: + cfg_versions = {} + + sys_versions = systemversions.get_system_versions() + + rev_versions = self.run_migration_scripts(cfg_versions, sys_versions) + + if rev_versions != cfg_versions: + self._changed = True + + if self.update_vintage(): + self._changed = True + + if not self._changed: + return + + formatversions.remove_versions(cfg_file) + + self.write_config_file_versions(rev_versions) + + def config_changed(self): + return self._changed + +class VirtualMigrator(Migrator): + def run(self): + cfg_file = self._config_file + + cfg_versions = self.read_config_file_versions() + if not cfg_versions: + return + + if self.update_vintage(): + self._changed = True + + if not self._changed: + return + + formatversions.remove_versions(cfg_file) + + self.write_config_file_versions(cfg_versions) + |