modified to use a single R/W snapshot

README.md

@@ -1,40 +1,25 @@
 # snap-pac
 
-![Tests](https://github.com/wesbarnett/snap-pac/workflows/Tests/badge.svg)
-![Docs](https://github.com/wesbarnett/snap-pac/workflows/Docs/badge.svg)
-
 ## Synopsis
 
-This is a set of [pacman](https://wiki.archlinux.org/index.php/Pacman) hooks and script
+This is a set of [pacman](https://wiki.archlinux.org/index.php/Pacman) hooks and scripts that automatically cause [snapper](http://snapper.io/) to perform a snapshot before pacman transactions.
-that automatically causes [snapper](http://snapper.io/) to perform a pre and post
-snapshot before and after pacman transactions, similar to how YaST does with OpenSuse.
-This provides a simple way to undo changes to a system after a pacman transaction.
 
-For more information, [see the documentation](https://wesbarnett.github.io/snap-pac/).
+Forked from Wes Barnett's solution for my own personal needs. Takes a single screenshot vs. the original's pre/post pair.
 
-## Installation
+## [Installation] (https://wesbarnett.github.io/snap-pac/installation.html).
-
-Install the `snap-pac` package using pacman.
-
-For instructions on how to install without pacman, [see the
-documentation](https://wesbarnett.github.io/snap-pac/installation.html).
 
 ## Configuration
 
-Most likely, configuration is not needed. By default, the snapper configuration named
+Most likely, configuration is not needed. By default, the snapper configuration named `root` will have snapshots taken before every pacman transaction.
-`root` will have pre/post snapshots taken for every pacman transaction.
 
-For more information on configuring snap-pac, see [the
+For more information on configuring snap-pac, see [the documentation](https://wesbarnett.github.io/snap-pac/configuration.html).
-documentation](https://wesbarnett.github.io/snap-pac/configuration.html).
 
 ## Documentation
 
-See the [documentation here](https://wesbarnett.github.io/snap-pac/) or `man 8 snap-pac`
+See the [documentation here](https://wesbarnett.github.io/snap-pac/) or `man 8 snap-pac` after installation.
-after installation.
 
 ## Troubleshooting
 
-After reviewing the documentation, [check the issues page] and file a new issue if your
+After reviewing the documentation, [check the issues page] and file a new issue if your problem is not covered.
-problem is not covered.
 
-[check the issues page]: https://github.com/wesbarnett/snap-pac/issues
+[check the issues page]: https://codeberg.org/ak95/snap-pac/issues

extra/snap-pac.ini

@@ -20,14 +20,6 @@
 ## Default is number
 #cleanup_algorithm = number
 
-## Pre snapshot description.
-## Default is the pacman command that triggered the hook
-#pre_description = pacman pre snapshot
-
-## Post snapshot description.
-## Default is the list of packages involved in the pacman transaction
-#post_description = pacman post snapshot
-
 ## Uncomment to add "important=yes" to userdata for snapshots referring to these packages
 ## Default is []
 #important_packages = ["linux", "linux-lts"]

hooks/05-snap-pac.hook

@@ -24,9 +24,9 @@ Type = Package
 Target = *
 
 [Action]
-Description = Performing snapper pre snapshots for the following configurations...
+Description = Taking snapper snapshot before installing...
 Depends = snap-pac
 When = PreTransaction
-Exec = /usr/share/libalpm/scripts/snap-pac pre
+Exec = /usr/share/libalpm/scripts/snap-pac
 NeedsTargets
 AbortOnFail

hooks/zz-snap-pac-post.hook

@@ -1,31 +0,0 @@
-# snap-pac
-# https://github.com/wesbarnett/snap-pac
-# Copyright (C) 2016, 2017, 2018 James W. Barnett
-
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or
-# (at your option) any later version.
-
-# This program 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 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.
-
-[Trigger]
-Operation = Upgrade
-Operation = Install
-Operation = Remove
-Type = Package
-Target = *
-
-[Action]
-Description = Performing snapper post snapshots for the following configurations...
-Depends = snap-pac
-When = PostTransaction
-Exec = /usr/share/libalpm/scripts/snap-pac post
-NeedsTargets

scripts/snap_pac.py

@@ -14,7 +14,7 @@
 # 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.
-"""Script for taking pre/post snapshots; run from pacman hooks."""
+"""Script for taking snapshots; run from pacman hooks."""
 
 from argparse import ArgumentParser
 from configparser import ConfigParser
@@ -31,8 +31,7 @@ logging.basicConfig(format="%(message)s", level=logging.INFO)
 
 class SnapperCmd:
 
-    def __init__(self, config, snapshot_type, cleanup_algorithm, description="",
+    def __init__(self, config, cleanup_algorithm, description="", nodbus=False, userdata=""):
-                 nodbus=False, pre_number=None, userdata=""):
         self.cmd = ["snapper"]
         if nodbus:
             self.cmd.append("--no-dbus")
@@ -41,19 +40,11 @@ class SnapperCmd:
             f"--cleanup-algorithm {cleanup_algorithm}",
             "--print-number"
         ])
+        self.cmd.append("--read-write")
         if description:
             self.cmd.append(f"--description \"{description}\"")
         if userdata:
             self.cmd.append(f"--userdata \"{userdata}\"")
-        if snapshot_type == "post":
-            if pre_number is not None:
-                self.cmd.append(f"--pre-number {pre_number}")
-            else:
-                logging.debug("snapshot type specified as 'post' but no pre snapshot number, "
-                              "so setting snapshot type to 'single'. If installing "
-                              "snap-pac this is normal.")
-                snapshot_type = "single"
-        self.cmd.append(f"--type {snapshot_type}")
 
     def __call__(self):
         return os.popen(self.__str__()).read().rstrip("\n")
@@ -64,7 +55,7 @@ class SnapperCmd:
 
 class ConfigProcessor:
 
-    def __init__(self, ini_file, snapshot_type, parent_cmd=None, packages=None):
+    def __init__(self, ini_file, parent_cmd=None, packages=None):
         """Set up defaults for snap-pac configuration."""
 
         if parent_cmd is None:
@@ -77,14 +68,11 @@ class ConfigProcessor:
         else:
             self.packages = packages
 
-        self.snapshot_type = snapshot_type
-
         self.config = ConfigParser()
         self.config["DEFAULT"] = {
             "snapshot": False,
             "cleanup_algorithm": "number",
-            "pre_description": self.parent_cmd,
+            "description": self.parent_cmd,
-            "post_description": " ".join(self.packages),
             "desc_limit": 72,
             "important_packages": [],
             "important_commands": [],
@@ -100,7 +88,7 @@ class ConfigProcessor:
 
     def get_description(self, section):
         desc_limit = self.config.getint(section, "desc_limit")
-        return self.config.get(section, f"{self.snapshot_type}_description")[:desc_limit]
+        return self.config.get(section, "description")[:desc_limit]
 
     def check_important_commands(self, section):
         return self.parent_cmd in json.loads(self.config.get(section, "important_commands"))
@@ -138,38 +126,12 @@ def get_snapper_configs(conf_file):
             return line[1].lstrip("\"").split()
 
 
-class Prefile:
-    """Handles reading and writing of pre snapshot number."""
-    def __init__(self, snapper_config, snapshot_type):
-        self.file = Path(tempfile.gettempdir()) / f"snap-pac-pre_{snapper_config}"
-        self.snapshot_type = snapshot_type
-
-    def read(self):
-        if self.snapshot_type == "pre":
-            pre_number = None
-        else:
-            try:
-                pre_number = self.file.read_text().rstrip("\n")
-            except FileNotFoundError:
-                pre_number = None
-                logging.debug(f"prefile {self.file} not found. Ensure you have run the pre snapshot first. "
-                              "If installing snap-pac this is normal.")
-            else:
-                self.file.unlink()
-        return pre_number
-
-    def write(self, num):
-        if self.snapshot_type == "pre":
-            self.file.write_text(num)
-
-
 def check_skip():
     return os.getenv("SNAP_PAC_SKIP", "n").lower() in ["y", "yes", "true", "1"]
 
 
 def parse_args():
-    parser = ArgumentParser(description="Script for taking pre/post snapper snapshots. Used with pacman hooks.")
+    parser = ArgumentParser(description="Script for taking snapper snapshots. Used with pacman hooks.")
-    parser.add_argument(dest="type", choices=["pre", "post"], help="snapper snapshot type")
     parser.add_argument(
         "--ini", dest="snap_pac_ini", type=Path,
         default=Path("/etc/snap-pac.ini"), help="snap-pac ini file path"
@@ -188,16 +150,12 @@ if __name__ == "__main__":
         quit()
 
     args = parse_args()
-    config_processor = ConfigProcessor(args.snap_pac_ini, args.type)
+    config_processor = ConfigProcessor(args.snap_pac_ini)
     chroot = os.stat("/") != os.stat("/proc/1/root/.")
 
     for snapper_config in get_snapper_configs(args.snapper_conf_file):
 
         data = config_processor(snapper_config)
         if data["snapshot"]:
-            prefile = Prefile(snapper_config, args.type)
+            num = SnapperCmd(snapper_config, data["cleanup_algorithm"], data["description"], chroot, data["userdata"])()
-            pre_number = prefile.read()
-            num = SnapperCmd(snapper_config, args.type, data["cleanup_algorithm"],
-                             data["description"], chroot, pre_number, data["userdata"])()
             logging.info(f"==> {snapper_config}: {num}")
-            prefile.write(num)