pre-transaction-actions plugin implementation

AUTHORS

@@ -38,3 +38,4 @@ DNF-PLUGINS-CORE CONTRIBUTORS
     Vladan Kudlac <[email protected]>
     Wieland Hoffmann <[email protected]>
     Otto Urpelainen <[email protected]>
+    Matija Skrgulja <[email protected]>

dnf-plugins-core.spec

@@ -328,6 +328,34 @@ Post transaction actions Plugin for DNF, Python 3 version. Plugin runs actions
 files.
 %endif
 
+%if %{with python2}
+%package -n python2-dnf-plugin-pre-transaction-actions
+Summary:        Pre transaction actions Plugin for DNF
+Requires:       python2-%{name} = %{version}-%{release}
+%if !%{with python3}
+Provides:       dnf-plugin-pre-transaction-actions =  %{version}-%{release}
+%endif
+Conflicts:      python3-dnf-plugin-pre-transaction-actions < %{version}-%{release}
+
+%description -n python2-dnf-plugin-pre-transaction-actions
+Pre transaction actions Plugin for DNF, Python 2 version. Plugin runs actions
+(shell commands) before transaction is completed. Actions are defined in action
+files.
+%endif
+
+%if %{with python3}
+%package -n python3-dnf-plugin-pre-transaction-actions
+Summary:        Pre transaction actions Plugin for DNF
+Requires:       python3-%{name} = %{version}-%{release}
+Provides:       dnf-plugin-pre-transaction-actions =  %{version}-%{release}
+Conflicts:      python2-dnf-plugin-pre-transaction-actions < %{version}-%{release}
+
+%description -n python3-dnf-plugin-pre-transaction-actions
+Pre transaction actions Plugin for DNF, Python 3 version. Plugin runs actions
+(shell commands) before transaction is completed. Actions are defined in action
+files.
+%endif
+
 %if 0%{?rhel} == 0 && %{with python2}
 %package -n python2-dnf-plugin-show-leaves
 Summary:        Leaves Plugin for DNF
@@ -746,6 +774,23 @@ ln -sf %{_mandir}/man1/%{yum_utils_subpackage_name}.1.gz %{buildroot}%{_mandir}/
 %{_mandir}/man8/dnf-post-transaction-actions.*
 %endif
 
+%if %{with python2}
+%files -n python2-dnf-plugin-pre-transaction-actions
+%config(noreplace) %{_sysconfdir}/dnf/plugins/pre-transaction-actions.conf
+%config(noreplace) %{_sysconfdir}/dnf/plugins/pre-transaction-actions.d
+%{python2_sitelib}/dnf-plugins/pre-transaction-actions.*
+%{_mandir}/man8/dnf-pre-transaction-actions.*
+%endif
+
+%if %{with python3}
+%files -n python3-dnf-plugin-pre-transaction-actions
+%config(noreplace) %{_sysconfdir}/dnf/plugins/pre-transaction-actions.conf
+%config(noreplace) %{_sysconfdir}/dnf/plugins/pre-transaction-actions.d
+%{python3_sitelib}/dnf-plugins/pre-transaction-actions.*
+%{python3_sitelib}/dnf-plugins/__pycache__/pre-transaction-actions.*
+%{_mandir}/man8/dnf-pre-transaction-actions.*
+%endif
+
 %if 0%{?rhel} == 0
 
 %if %{with python2}

doc/CMakeLists.txt

@@ -36,6 +36,7 @@ INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/dnf-builddep.8
     ${CMAKE_CURRENT_BINARY_DIR}/dnf-repomanage.8
     ${CMAKE_CURRENT_BINARY_DIR}/dnf-reposync.8
     ${CMAKE_CURRENT_BINARY_DIR}/dnf-post-transaction-actions.8
+    ${CMAKE_CURRENT_BINARY_DIR}/dnf-pre-transaction-actions.8
     ${CMAKE_CURRENT_BINARY_DIR}/dnf-show-leaves.8
     ${CMAKE_CURRENT_BINARY_DIR}/dnf-system-upgrade.8
     ${CMAKE_CURRENT_BINARY_DIR}/dnf-versionlock.8

doc/conf.py

@@ -263,6 +263,8 @@ def version_readout():
     ('reposync', 'dnf-reposync', u'DNF reposync Plugin', AUTHORS, 8),
     ('post-transaction-actions', 'dnf-post-transaction-actions',
      u'DNF post transaction actions Plugin', AUTHORS, 8),
+    ('pre-transaction-actions', 'dnf-pre-transaction-actions',
+     u'DNF pre transaction actions Plugin', AUTHORS, 8),
     ('show-leaves', 'dnf-show-leaves', u'DNF show-leaves Plugin', AUTHORS, 8),
     ('system-upgrade', 'dnf-system-upgrade', u'DNF system-upgrade Plugin', AUTHORS, 8),
     ('versionlock', 'dnf-versionlock', u'DNF versionlock Plugin', AUTHORS, 8),

doc/index.rst

@@ -40,6 +40,7 @@ This documents core plugins of DNF:
    modulesync
    needs_restarting
    post-transaction-actions
+   pre-transaction-actions
    repoclosure
    repodiff
    repograph

doc/pre-transaction-actions.rst

@@ -0,0 +1,96 @@
+..
+  Copyright (C) 2019 Red Hat, Inc.
+
+  This copyrighted material is made available to anyone wishing to use,
+  modify, copy, or redistribute it subject to the terms and conditions of
+  the GNU General Public License v.2, or (at your option) any later version.
+  This program is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY expressed or implied, including the implied warranties of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+  Public License for more details.  You should have received a copy of the
+  GNU General Public License along with this program; if not, write to the
+  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+  02110-1301, USA.  Any Red Hat trademarks that are incorporated in the
+  source code or documentation are not subject to the GNU General Public
+  License and may only be used or replicated with the express permission of
+  Red Hat, Inc.
+
+===================================
+DNF pre-transaction-actions Plugin
+===================================
+
+-----------
+Description
+-----------
+
+The plugin allows to define actions to be executed upon starting an RPM transaction. Each action
+may define a (glob-like) filtering rule on the package NEVRA or package files, as well as whether
+the package was installed or removed. Actions are defined in action files.
+
+-------------
+Configuration
+-------------
+
+The plugin configuration is in ``/etc/dnf/plugins/pre-transaction-actions.conf``. All configuration
+options are in the ``[main]`` section.
+
+``enabled``
+    Whether the plugin is enabled. Default value is ``True``.
+
+``actiondir``
+    Path to the directory with action files. Action files must have the ".action" extension.
+    Default value is "/etc/dnf/plugins/pre-transaction-actions.d/".
+
+------------------
+Action file format
+------------------
+
+Empty lines and lines that start with a '#' character are ignored.
+Each non-comment line defines an action and consists of three items separated by colons:
+``package_filter:transaction_state:command``.
+
+``package_filter``
+   A (glob-like) filtering rule applied on the package NEVRA (also in the shortened forms) or
+   package files.
+
+``transaction_state``
+   Filters packages according to their state in the transaction.
+
+   * ``in`` - packages that will appeared on the system (downgrade, install, obsolete, reinstall, upgrade)
+   * ``out`` - packages that will disappeared from the system (downgraded, obsoleted, remove, upgraded)
+   * ``any`` - all packages
+
+``command``
+   Any shell command.
+   The following variables in the command will be substituted:
+      * ``${name}``, ``$name`` - package name
+      * ``${arch}``, ``$arch`` - package arch
+      * ``${ver}``, ``$ver`` - package version
+      * ``${rel}``, ``$rel`` - package release
+      * ``${epoch}``, ``$epoch`` - package epoch
+      * ``${repoid}``, ``$repoid`` - package repository id
+      * ``${state}``, ``$state`` - the change of package state in the transaction:
+         "downgrade", "downgraded", "install", "obsolete", "obsoleted", "reinstall",
+         "reinstalled", "remove", "upgrade", "upgraded"
+
+   The shell command will be evaluated for each package that matched the ``package_filter`` and
+   the ``transaction_state``. However, after variable substitution, any duplicate commands will be
+   removed and each command will only be executed once per transaction. The order of execution
+   of the commands follows the order in the action files, but may differ from the order of
+   packages in the transaction.  In other words, when you define several action lines for the
+   same ``package_filter`` these lines will be executed in the order they were defined in the
+   action file when the ``package_filter`` matches a package during the ``trasaction_state`` state.
+   However, the order of when a particular ``package_filter`` is invoked depends on the position
+   of the corresponding package in the transaction.
+
+An example action file:
+^^^^^^^^^^^^^^^^^^^^^^^
+.. code-block:: none
+
+   # log all packages (state, nevra, repo) in transaction into a file.
+   *:any:echo '${state} ${name}-${epoch}:${ver}-${rel}.${arch} repo ${repoid}' >>/tmp/pre-trans-actions-trans.log
+
+   # The same shell command (after variables substitution) is executed only once per transaction.
+   *:any:echo '${repoid}' >>/tmp/pre-trans-actions-repos
+   # will write each repo only once to /tmp/pre-trans-actions-repos, even if multiple packages from
+   # the same repo were matched

etc/dnf/plugins/CMakeLists.txt

@@ -1,5 +1,6 @@
 ADD_SUBDIRECTORY (copr.d)
 ADD_SUBDIRECTORY (post-transaction-actions.d)
+ADD_SUBDIRECTORY (pre-transaction-actions.d)
 INSTALL (FILES copr.conf DESTINATION ${SYSCONFDIR}/dnf/plugins)
 INSTALL (FILES debuginfo-install.conf DESTINATION ${SYSCONFDIR}/dnf/plugins)
 if (${WITHOUT_LOCAL} STREQUAL "0")
@@ -8,3 +9,4 @@ endif()
 INSTALL (FILES versionlock.conf DESTINATION ${SYSCONFDIR}/dnf/plugins)
 INSTALL (FILES versionlock.list DESTINATION ${SYSCONFDIR}/dnf/plugins)
 INSTALL (FILES post-transaction-actions.conf DESTINATION ${SYSCONFDIR}/dnf/plugins)
+INSTALL (FILES pre-transaction-actions.conf DESTINATION ${SYSCONFDIR}/dnf/plugins)

etc/dnf/plugins/pre-transaction-actions.conf

@@ -0,0 +1,4 @@
+[main]
+enabled = 1
+actiondir = /etc/dnf/plugins/pre-transaction-actions.d/
+

etc/dnf/plugins/pre-transaction-actions.d/CMakeLists.txt

@@ -0,0 +1 @@
+INSTALL (DIRECTORY . DESTINATION ${SYSCONFDIR}/dnf/plugins/pre-transaction-actions.d FILES_MATCHING PATTERN "(NONE)")

plugins/CMakeLists.txt

@@ -16,6 +16,7 @@ INSTALL (FILES migrate.py DESTINATION ${PYTHON_INSTALL_DIR}/dnf-plugins)
 endif()
 INSTALL (FILES needs_restarting.py DESTINATION ${PYTHON_INSTALL_DIR}/dnf-plugins)
 INSTALL (FILES post-transaction-actions.py DESTINATION ${PYTHON_INSTALL_DIR}/dnf-plugins)
+INSTALL (FILES pre-transaction-actions.py DESTINATION ${PYTHON_INSTALL_DIR}/dnf-plugins)
 INSTALL (FILES repoclosure.py DESTINATION ${PYTHON_INSTALL_DIR}/dnf-plugins)
 INSTALL (FILES repodiff.py DESTINATION ${PYTHON_INSTALL_DIR}/dnf-plugins)
 INSTALL (FILES repograph.py DESTINATION ${PYTHON_INSTALL_DIR}/dnf-plugins)

plugins/pre-transaction-actions.py

@@ -0,0 +1,150 @@
+"""
+This plugin is basically a POST-transaction-actions plugin
+but modified (with minimall changes) to work as pre-transaction-actions plugin
+
+The plugin allows to define actions to be executed before an RPM transaction. Each action
+may define a (glob-like) filtering rule on the package NEVRA or package files, as well as whether
+the package was installed or removed. Actions are defined in action files.
+
+The action can start any shell command. Commands can contain variables. The same command (after
+variables substitution) is executed only once per transaction. The order of execution
+of the commands may differ from the order of the packages in the transaction.
+"""
+
+from dnfpluginscore import _, logger
+
+import libdnf.conf
+import dnf
+import dnf.transaction
+import glob
+import os
+import subprocess
+
+
+class PreTransactionActions(dnf.Plugin):
+
+    name = "pre-transaction-actions"
+
+    def __init__(self, base, cli):
+        super(PreTransactionActions, self).__init__(base, cli)
+        self.actiondir = "/etc/dnf/plugins/pre-transaction-actions.d/"
+        self.base = base
+        self.logger = logger
+
+    def config(self):
+        conf = self.read_config(self.base.conf)
+        if conf.has_section("main"):
+            if conf.has_option("main", "actiondir"):
+                self.actiondir = conf.get("main", "actiondir")
+
+    def _parse_actions(self):
+        """Parses *.action files from self.actiondir path.
+        Parsed actions are stored in a list of tuples."""
+
+        action_file_list = []
+        if os.access(self.actiondir, os.R_OK):
+            action_file_list.extend(glob.glob(self.actiondir + "*.action"))
+
+        action_tuples = []  # (action key, action_state, shell command)
+        for file_name in action_file_list:
+            for line in open(file_name).readlines():
+                line = line.strip()
+                if line and line[0] != "#":
+                    try:
+                        (action_key, action_state, action_command) = line.split(':', 2)
+                    except ValueError as e:
+                        self.logger.error(_('Bad Action Line "%s": %s') % (line, e))
+                        continue
+                    else:
+                        action_tuples.append((action_key, action_state, action_command))
+
+        return action_tuples
+
+    def _replace_vars(self, ts_item, command):
+        """Replaces variables in the command.
+        Variables: ${name}, ${arch}, ${ver}, ${rel}, ${epoch}, ${repoid}, ${state}
+        or $name, $arch, $ver, $rel, $epoch, $repoid, $state"""
+
+        action_dict = {dnf.transaction.PKG_DOWNGRADE: "downgrade",
+                       dnf.transaction.PKG_DOWNGRADED: "downgraded",
+                       dnf.transaction.PKG_INSTALL: "install",
+                       dnf.transaction.PKG_OBSOLETE: "obsolete",
+                       dnf.transaction.PKG_OBSOLETED: "obsoleted",
+                       dnf.transaction.PKG_REINSTALL: "reinstall",
+                       dnf.transaction.PKG_REINSTALLED: "reinstalled",
+                       dnf.transaction.PKG_REMOVE: "remove",
+                       dnf.transaction.PKG_UPGRADE: "upgrade",
+                       dnf.transaction.PKG_UPGRADED: "upgraded"}
+
+        action = action_dict.get(ts_item.action, "unknown - %s" % ts_item.action)
+
+        vardict = {"name": ts_item.name,
+                   "arch": ts_item.arch,
+                   "ver": ts_item.version,
+                   "rel": ts_item.release,
+                   "epoch": str(ts_item.epoch),
+                   "repoid": ts_item.from_repo,
+                   "state": action}
+
+        result = libdnf.conf.ConfigParser.substitute(command, vardict)
+        return result
+
+    def pre_transaction(self):
+        action_tuples = self._parse_actions()
+
+        in_ts_items = []
+        out_ts_items = []
+        all_ts_items = []
+        for ts_item in self.base.transaction:
+            if ts_item.action in dnf.transaction.FORWARD_ACTIONS:
+                in_ts_items.append(ts_item)
+            elif ts_item.action in dnf.transaction.BACKWARD_ACTIONS:
+                out_ts_items.append(ts_item)
+            else:
+                #  The action is not rpm change. It can be a reason change, therefore we can skip that item
+                continue
+            all_ts_items.append(ts_item)
+
+        commands_to_run = []
+        for (a_key, a_state, a_command) in action_tuples:
+            if a_state == "in":
+                ts_items = in_ts_items
+            elif a_state == "out":
+                ts_items = out_ts_items
+            elif a_state == "any":
+                ts_items = all_ts_items
+            else:
+                # unsupported state, skip it
+                self.logger.error(_("Bad Transaction State: %s") % a_state)
+                continue
+
+            subj = dnf.subject.Subject(a_key)
+            pkgs = [tsi.pkg for tsi in ts_items]
+            query = self.base.sack.query().filterm(pkg=pkgs)
+            query = subj.get_best_query(self.base.sack, with_nevra=True, with_provides=False,
+                                        with_filenames=True, query=query)
+
+            for pkg in query:
+                ts_item_list = [tsi for tsi in ts_items
+                                if tsi.pkg == pkg and tsi.pkg.reponame == pkg.reponame]
+                ts_item = ts_item_list[0]
+                command = self._replace_vars(ts_item, a_command)
+                commands_to_run.append(command)
+
+        # de-dup the list
+        seen = set()
+        commands_to_run = [x for x in commands_to_run if x not in seen and not seen.add(x)]
+
+        for command in commands_to_run:
+            try:
+                proc = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE,
+                                        stderr=subprocess.PIPE, close_fds=True,
+                                        universal_newlines=True)
+                stdout, stderr = proc.communicate()
+                if stdout:
+                    self.logger.info(_('pre-transaction-actions: %s') % (stdout))
+                if stderr:
+                    self.logger.error(_('pre-transaction-actions: %s') % (stderr))
+            except Exception as e:
+                self.logger.error(_('pre-transaction-actions: Bad Command "%s": %s') %
+                                  (command, e))