FreedomBox/plinth/package.py
Sunil Mohan Adapa e26a4b71eb
package: Uninstall packages even if they are not in apt cache
Tests:

- Install matrix-synapse app by adding 'unstable' in apt sources.list. Then
remove 'unstable' from apt sources.list. Then matrix-synapse package will no
longer be found in the apt's cache.

- Try to uninstall the package. Without patch, the process errors out. With
patch, uninstall completes successfully.

- While matrix-synapse app is installed and apt cache does not contain
matrix-synapse package, install and uninstall bepasty app. Without patch,
uninstall fails. With patch, uninstall succeeds.

- Install and uninstall minetest app. 3d armor mod package is successfully
installed.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: Joseph Nuthalapati <njoseph@riseup.net>
2025-08-16 23:04:05 +05:30

601 lines
21 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
"""Framework for installing and updating distribution packages."""
import enum
import logging
import pathlib
import time
import apt
import apt.cache
from django.utils.translation import gettext as _
from django.utils.translation import gettext_lazy, gettext_noop
import plinth.privileged.packages as privileged
from plinth import app as app_module
from plinth.diagnostic_check import (DiagnosticCheck,
DiagnosticCheckParameters, Result)
from plinth.errors import MissingPackageError
from plinth.utils import format_lazy
from . import kvstore
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: str | None = None, # ">=1.0,<2.0"
distribution: str | None = None, # Debian, Ubuntu
suite: str | None = None, # stable, testing
codename: str | None = None, # bullseye-backports
architecture: str | None = 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()
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.
"""
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
def __init__(self, component_id: str,
packages: list[str | PackageExpression],
skip_recommends: bool = False,
conflicts: list[str] | None = None,
conflicts_action: ConflictsAction | None = None,
rerun_setup_on_upgrade: bool = False):
"""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.
'rerun_setup_on_upgrade' is a boolean to specify whether app's setup
process should be rerun if a .deb package is upgraded (by someone other
than FreedomBox process).
"""
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
self.rerun_setup_on_upgrade = rerun_setup_on_upgrade
@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
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
]
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)
def uninstall(self):
"""Uninstall and purge the packages."""
# Ensure package list is update-to-date before looking at dependencies.
refresh_package_lists()
# List of packages to purge from the system. Be resilient to a package
# not being found in apt's cache by not using get_actual_packages(). If
# a package expression is listed as (package1 | package2) then try to
# remove both packages.
packages = self.possible_packages
logger.info('App\'s list of packages to remove: %s', packages)
packages = self._filter_packages_to_keep(packages)
uninstall(packages, purge=True)
def diagnose(self) -> list[DiagnosticCheck]:
"""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:
check_id = f'package-available-{package_expression}'
description = gettext_noop('Package {package_expression} is '
'not available for install')
parameters: DiagnosticCheckParameters = {
'package_expression': str(package_expression)
}
results.append(
DiagnosticCheck(check_id, description, Result.FAILED,
parameters, self.component_id))
continue
result = Result.WARNING
latest_version = '?'
if package_name in cache:
package = cache[package_name]
if package.candidate:
latest_version = package.candidate.version
if package.candidate.is_installed:
result = Result.PASSED
check_id = f'package-latest-{package_name}'
description = gettext_noop('Package {package_name} is the latest '
'version ({latest_version})')
parameters = {
'package_name': str(package_name),
'latest_version': str(latest_version)
}
results.append(
DiagnosticCheck(check_id, description, result, parameters,
self.component_id))
return results
def find_conflicts(self) -> list[str] | None:
"""Return list of conflicting packages installed on the system."""
if not self.conflicts:
return None
return packages_installed(self.conflicts)
def is_available(self) -> bool:
"""Return whether all of the packages are available.
Returns True if all of the packages are available in the user's Debian
distribution or False otherwise. Returns True if it cannot be reliably
determined whether the packages are available or not.
This operation can run for a long time as package cache may be
refreshed.
"""
try:
self.get_actual_packages()
return True # All packages were found in the cache
except MissingPackageError:
pass # We will retry after refreshing package list
# If the package cache is new, then package is really not available.
package_cache = pathlib.Path('/var/cache/apt/pkgcache.bin')
if (package_cache.exists()
and time.time() - package_cache.stat().st_mtime < 3600):
return False
# Perform 'apt-get update'
refresh_package_lists()
# Check again for all the packages
try:
self.get_actual_packages()
except MissingPackageError:
return False
return True
def _filter_packages_to_keep(self, packages: list[str]) -> list[str]:
"""Filter out the list of packages to keep from given list.
Packages to keep are packages needed by other installed apps and their
dependencies (PreDepends, Depends, Recommends).
"""
packages_set: set[str] = set(packages)
# Get list of packages needed by other installed apps (packages to
# keep).
keep_packages: set[str] = set()
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):
keep_packages |= set(component.possible_packages)
# Get list of all the dependencies of packages to keep.
keep_packages_with_deps: set[str] = set()
cache = apt.Cache()
while keep_packages:
package_name = keep_packages.pop()
if package_name in keep_packages_with_deps:
continue # Already processed
keep_packages_with_deps.add(package_name)
if package_name not in cache:
continue # Package is not available in sources
if not cache[package_name].is_installed:
continue # Package is not installed
version = cache[package_name].installed
if not version:
continue
dependencies = version.dependencies + version.recommends
for dependency in dependencies:
for or_dependency in dependency.or_dependencies:
keep_packages.add(or_dependency.name)
# Filter out any packages that are to be kept or their dependencies.
packages_set -= keep_packages_with_deps
# Preserve order of packages for ease of testing.
return [package for package in packages if package in packages_set]
class PackageException(Exception):
"""A package operation has failed."""
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)
mark_known(package_names)
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)
unmark_known(package_names)
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: 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
def get_known() -> dict[str, dict]:
"""Return all the known packages and their versions.
If a package is not known or has a version lower than the currently
installed version, it means that the package has been installe or updated
outside of FreedomBox. Some app, may use this information to rerun the
setup on the app so that configuration is updated.
"""
return kvstore.get_default('packages_known', {})
def mark_known(packages: list[str]):
"""Mark a given list of packages as known."""
packages_known = get_known()
cache = apt.Cache()
for package_ in packages:
try:
cache_package = cache[package_]
except KeyError:
logger.warn('Package %s is not found when marking known', package_)
continue
if not cache_package.installed:
logger.warn('Package %s is not installed when marking known',
package_)
continue
installed_version = cache_package.installed.version
package_known = packages_known.setdefault(package_, {})
package_known['version'] = installed_version
kvstore.set('packages_known', packages_known)
def unmark_known(packages: list[str]):
"""Mark a give list of packages unknown."""
packages_known = get_known()
for package_ in packages:
try:
packages_known.pop(package_)
except KeyError:
pass
kvstore.set('packages_known', packages_known)