From bdd8224bd19d0972eb0f41bc0dfe170a5d24ed35 Mon Sep 17 00:00:00 2001
From: Marek Blaha <mblaha@redhat.com>
Date: Thu, 17 Oct 2024 13:30:21 +0200
Subject: [PATCH] automatic: Check availability of config file

If a configuration file is explicitly specified on the command line,
ensure that it exists and is readable. If the file is not found, notify
the user immediately and terminate the process.

This resolves issues where users may run dnf-automatic with unrecognized
positional arguments, such as `dnf-automatic install`.

The most natural approach to handle a non-existing config file would be
by catching the exception thrown by the `read()` method of the
`libdnf.conf.ConfigParser` class. Unfortunately, the Python bindings
override the `read()` method at the SWIG level, causing it to suppress any
potentially raised IOError.
For details see this section of the commit
https://github.com/rpm-software-management/libdnf/commit/8f1fedf8551b72d6bc24018f5980714b3a103aeb

def ConfigParser__newRead(self, filenames):
    parsedFNames = []
    try:
        if isinstance(filenames, str) or isinstance(filenames, unicode):
            filenames = [filenames]
    except NameError:
        pass
    for fname in filenames:
        try:
            self.readFileName(fname)
            parsedFNames.append(fname)
        except IOError:
            pass
        except Exception as e:
            raise RuntimeError("Parsing file '%s' failed: %s" % (fname, str(e)))
    return parsedFNames
ConfigParser.read = ConfigParser__newRead

Resolves: https://issues.redhat.com/browse/RHEL-46030
---
 dnf/automatic/main.py | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/dnf/automatic/main.py b/dnf/automatic/main.py
index 243e301580..21aa82b75d 100644
--- a/dnf/automatic/main.py
+++ b/dnf/automatic/main.py
@@ -74,7 +74,7 @@ def build_emitters(conf):
 
 def parse_arguments(args):
     parser = argparse.ArgumentParser()
-    parser.add_argument('conf_path', nargs='?', default=dnf.const.CONF_AUTOMATIC_FILENAME)
+    parser.add_argument('conf_path', nargs='?')
     parser.add_argument('--timer', action='store_true')
     parser.add_argument('--installupdates', dest='installupdates', action='store_true')
     parser.add_argument('--downloadupdates', dest='downloadupdates', action='store_true')
@@ -89,7 +89,17 @@ def parse_arguments(args):
 class AutomaticConfig(object):
     def __init__(self, filename=None, downloadupdates=None,
                  installupdates=None):
-        if not filename:
+        if filename:
+            # Specific config file was explicitely requested. Check that it exists
+            # and is readable.
+            if os.access(filename, os.F_OK):
+                if not os.access(filename, os.R_OK):
+                    raise dnf.exceptions.Error(
+                        "Configuration file \"{}\" is not readable.".format(filename))
+            else:
+                raise dnf.exceptions.Error(
+                    "Configuration file \"{}\" not found.".format(filename))
+        else:
             filename = dnf.const.CONF_AUTOMATIC_FILENAME
         self.commands = CommandsConfig()
         self.email = EmailConfig()
@@ -302,11 +312,12 @@ def remote_address(url_list):
 
 def main(args):
     (opts, parser) = parse_arguments(args)
+    conf = None
+    emitters = None
 
     try:
         conf = AutomaticConfig(opts.conf_path, opts.downloadupdates,
                                opts.installupdates)
-        emitters = None
         with dnf.Base() as base:
             cli = dnf.cli.Cli(base)
             cli._read_conf_file()
@@ -371,7 +382,7 @@ def main(args):
                     raise dnf.exceptions.Error('reboot command returned nonzero exit code: %d', exit_code)
     except dnf.exceptions.Error as exc:
         logger.error(_('Error: %s'), ucd(exc))
-        if conf.emitters.send_error_messages and emitters != None:
+        if conf is not None and conf.emitters.send_error_messages and emitters is not None:
             emitters.notify_error(_('Error: %s') % str(exc))
             emitters.commit()
         return 1