Source code for plinth.package

# SPDX-License-Identifier: AGPL-3.0-or-later
"""Framework for installing and updating distribution packages."""

import enum
import logging
import pathlib
import time
from typing import Optional, Union

import apt.cache
from django.utils.translation import gettext as _
from django.utils.translation import gettext_lazy

import plinth.privileged.packages as privileged
from plinth import app as app_module
from plinth.errors import MissingPackageError
from plinth.utils import format_lazy

from . import operation as operation_module
from .errors import PackageNotInstalledError

logger = logging.getLogger(__name__)


class PackageExpression:

    def possible(self) -> list[str]:
        """Return the list of possible packages before resolving."""
        raise NotImplementedError

    def actual(self) -> str:
        """Return the name of the package to install.

        TODO: Also return version and suite to install from.
        """
        raise NotImplementedError


class Package(PackageExpression):

    def __init__(
            self,
            name,
            optional: bool = False,
            version: Optional[str] = None,  # ">=1.0,<2.0"
            distribution: Optional[str] = None,  # Debian, Ubuntu
            suite: Optional[str] = None,  # stable, testing
            codename: Optional[str] = None,  # bullseye-backports
            architecture: Optional[str] = None):  # arm64
        self.name = name
        self.optional = optional
        self.version = version
        self.distribution = distribution
        self.suite = suite
        self.codename = codename
        self.architecture = architecture

    def __repr__(self):
        return self.name

    def __or__(self, other):
        return PackageOr(self, other)

    def possible(self) -> list[str]:
        return [self.name]

    def actual(self) -> str:
        cache = apt.Cache()
        if self.name in cache:
            # TODO: Also return version and suite to install from
            return self.name

        raise MissingPackageError(self.name)


class PackageOr(PackageExpression):
    """Specify that one of the two packages will be installed."""

    def __init__(self, package1: PackageExpression,
                 package2: PackageExpression):
        self.package1 = package1
        self.package2 = package2

    def __repr__(self):
        return self.package1.name + ' | ' + self.package2.name

    def possible(self) -> list[str]:
        return self.package1.possible() + self.package2.possible()

    def actual(self) -> str:
        try:
            return self.package1.actual()
        except MissingPackageError:
            return self.package2.actual()


[docs]class Packages(app_module.FollowerComponent): """Component to manage the packages of an app. This component is responsible for installation, upgrades and uninstallation of packages required by an app. """
[docs] class ConflictsAction(enum.Enum): """Action to take when a conflicting package is installed.""" IGNORE = 'ignore' # Proceed as if there are no conflicts REMOVE = 'remove' # Remove the packages before installing the app
[docs] def __init__(self, component_id: str, packages: list[Union[str, PackageExpression]], skip_recommends: bool = False, conflicts: Optional[list[str]] = None, conflicts_action: Optional[ConflictsAction] = None): """Initialize a new packages component. 'component_id' should be a unique ID across all components of an app and across all components. 'packages' is the list of Debian packages managed by this component. 'skip_recommends' is a boolean specifying whether recommended packages should be installed along with the listed packages. 'conflicts' is the list of Debian packages that can't simultaneously be installed with packages listed here. None if there are no known conflicting packages. 'conflicts_action' is a string representing the action to take when it is found that conflicting Debian packages are installed on the system. None if there are no known conflicting packages. """ super().__init__(component_id) self.component_id = component_id self._packages: list[PackageExpression] = [] for package in packages: if isinstance(package, str): self._packages.append(Package(package)) else: self._packages.append(package) self.skip_recommends = skip_recommends self.conflicts = conflicts or [] self.conflicts_action = conflicts_action
@property def package_expressions(self) -> list[PackageExpression]: """Return the list of managed packages as expressions.""" return self._packages @property def possible_packages(self) -> list[str]: """Return the list of possible packages before resolving.""" packages: list[str] = [] for package_expression in self.package_expressions: packages.extend(package_expression.possible()) return packages
[docs] def get_actual_packages(self) -> list[str]: """Return the computed list of packages to install. Raise MissingPackageError if a required package is not available. """ return [ package_expression.actual() for package_expression in self.package_expressions ]
[docs] def setup(self, old_version): """Install the packages.""" packages_to_remove = self.find_conflicts() if packages_to_remove and \ self.conflicts_action not in (None, self.ConflictsAction.IGNORE): logger.info('Removing conflicting packages: %s', packages_to_remove) uninstall(packages_to_remove, purge=False) install(self.get_actual_packages(), skip_recommends=self.skip_recommends)
[docs] def uninstall(self): """Uninstall and purge the packages.""" packages = self.get_actual_packages() packages_set = set(packages) for app in app_module.App.list(): # uninstall() will be called on Packages of this app separately # for uninstalling this app. if app == self.app: continue if app.get_setup_state() == app_module.App.SetupState.NEEDS_SETUP: continue # Remove packages used by other installed apps for component in app.get_components_of_type(Packages): packages_set -= set(component.get_actual_packages()) # Preserve order of packages for ease of testing uninstall([package for package in packages if package in packages_set], purge=True)
[docs] def diagnose(self): """Run diagnostics and return results.""" results = super().diagnose() cache = apt.Cache() for package_expression in self.package_expressions: try: package_name = package_expression.actual() except MissingPackageError: message = _('Package {expression} is not available for ' 'install').format(expression=package_expression) results.append([message, 'failed']) continue result = 'warning' latest_version = '?' if package_name in cache: package = cache[package_name] latest_version = package.candidate.version if package.candidate.is_installed: result = 'passed' message = _('Package {package_name} is the latest version ' '({latest_version})').format( package_name=package_name, latest_version=latest_version) results.append([message, result]) return results
[docs] def find_conflicts(self) -> Optional[list[str]]: """Return list of conflicting packages installed on the system.""" if not self.conflicts: return None return packages_installed(self.conflicts)
[docs] def has_unavailable_packages(self) -> Optional[bool]: """Return whether any of the packages are not available. Returns True if one or more of the packages is not available in the user's Debian distribution or False otherwise. Returns None if it cannot be reliably determined whether the packages are available or not. """ apt_lists_dir = pathlib.Path('/var/lib/apt/lists/') num_files = len( [child for child in apt_lists_dir.iterdir() if child.is_file()]) if num_files < 2: # not counting the lock file return None # List of all packages from all Package components try: self.get_actual_packages() except MissingPackageError: return True return False
class PackageException(Exception): """A package operation has failed.""" def __init__(self, error_string=None, error_details=None, *args, **kwargs): """Store apt-get error string and details.""" super().__init__(*args, **kwargs) self.error_string = error_string self.error_details = error_details def __str__(self): """Return the strin representation of the exception.""" return 'PackageException(error_string="{0}", error_details="{1}")' \ .format(self.error_string, self.error_details) class Transaction: """Information about an ongoing transaction.""" def __init__(self, app_id, package_names): """Initialize transaction object. Set most values to None until they are sent as progress update. """ self.app_id = app_id self.package_names = package_names self._reset_status() def get_id(self): """Return a identifier to use as a key in a map of transactions.""" return frozenset(self.package_names) def _reset_status(self): """Reset the current status progress.""" self.status_string = '' self.percentage = 0 self.stderr = None def install(self, skip_recommends=False, force_configuration=None, reinstall=False, force_missing_configuration=False): """Run an apt-get transaction to install given packages. If force_configuration is set to 'new', dpkg options will be enabled to make it force overwrite (without prompts) new configuration in place of old configuration (with a backup). This is useful when writing migration scripts in FreedomBox to handle the upgrades when unattended-upgrades refuse to upgrade a package due to configuration prompts. If force_configuration is set to 'old', dpkg options will be enabled to make it keep the old configuration (without prompts). This is useful when the Debian packages introduce new configuration with just cosmetics (such as updates to comments) and keeping the old configuration has same semantics. If force_configuration is None, no special options are passed to apt/dpkg for configuration file behavior. If reinstall is True, packages will be reinstalled, even if they are the latest version. If force_missing_configuration is True, any configuration files that have been removed after the first package has been installed will be restored. """ try: privileged.update() kwargs = { 'app_id': self.app_id, 'packages': self.package_names, 'skip_recommends': skip_recommends, 'force_configuration': force_configuration, 'reinstall': reinstall, 'force_missing_configuration': force_missing_configuration } privileged.install(**kwargs) except Exception as exception: logger.exception('Error installing package: %s', exception) raise def uninstall(self, purge): """Run an apt-get transaction to uninstall given packages.""" try: privileged.remove(app_id=self.app_id, packages=self.package_names, purge=purge) except Exception as exception: logger.exception('Error uninstalling package: %s', exception) raise def refresh_package_lists(self): """Refresh apt package lists.""" try: privileged.update() except Exception as exception: logger.exception('Error updating package lists: %s', exception) raise def _parse_progress(self, line): """Parse the apt-get process output line. See README.progress-reporting in apt source code. """ parts = line.split(':') if len(parts) < 4: return status_map = { 'pmstatus': gettext_lazy('installing'), 'dlstatus': gettext_lazy('downloading'), 'media-change': gettext_lazy('media change'), 'pmconffile': format_lazy(gettext_lazy('configuration file: {file}'), file=parts[1]), } self.status_string = status_map.get(parts[0], '') self.percentage = int(float(parts[2])) def install(package_names, skip_recommends=False, force_configuration=None, reinstall=False, force_missing_configuration=False): """Install a set of packages marking progress.""" try: operation = operation_module.Operation.get_operation() except AttributeError: raise RuntimeError( 'install() must be called from within an operation.') if not operation.thread_data.get('allow_install', True): # Raise error if packages are not already installed. cache = apt.Cache() for package_name in package_names: if not cache[package_name].is_installed: raise PackageNotInstalledError(package_name) return start_time = time.time() while is_package_manager_busy(): if time.time() - start_time >= 24 * 3600: # One day raise PackageException(_('Timeout waiting for package manager')) time.sleep(3) # seconds logger.info('Running install for app - %s, packages - %s', operation.app_id, package_names) from . import package transaction = package.Transaction(operation.app_id, package_names) operation.thread_data['transaction'] = transaction transaction.install(skip_recommends, force_configuration, reinstall, force_missing_configuration) def uninstall(package_names, purge): """Uninstall a set of packages.""" try: operation = operation_module.Operation.get_operation() except AttributeError: raise RuntimeError( 'uninstall() must be called from within an operation.') start_time = time.time() while is_package_manager_busy(): if time.time() - start_time >= 24 * 3600: # One day raise PackageException(_('Timeout waiting for package manager')) time.sleep(3) # seconds logger.info('Running uninstall for app - %s, packages - %s', operation.app_id, package_names) from . import package transaction = package.Transaction(operation.app_id, package_names) operation.thread_data['transaction'] = transaction transaction.uninstall(purge) def is_package_manager_busy(): """Return whether a package manager is running.""" try: return privileged.is_package_manager_busy(_log_error=False) except Exception: return False def refresh_package_lists(): """To be run in case apt package lists are outdated.""" transaction = Transaction(None, None) transaction.refresh_package_lists() def filter_conffile_prompt_packages(packages): """Return a filtered info on packages that require conffile prompts. Information for each package includes: current_version, new_version and list of modified_conffiles. """ return privileged.filter_conffile_packages(list(packages)) def packages_installed(candidates: Union[list, tuple]) -> list: """Check which candidates are installed on the system. :param candidates: A list of package names. :return: A list of installed Debian package names. """ cache = apt.cache.Cache() installed_packages = [] for package_name in candidates: try: package = cache[package_name] if package.is_installed: installed_packages.append(package_name) except KeyError: pass return installed_packages