[Pkg-nagios-devel] Bug#1070073: check_libs_ng sometimes returns "No such file or directory"

[Evgeni Golov]

On Mon, Apr 29, 2024 at 08:35:28PM +0200, Evgeni Golov wrote:
> UNKNOWN Exception: [Errno 2] No such file or directory: <some map file>
> 
> This is because the process might have already ended between calling
> os.listdir() and os.stat().

Turns out, os.path.realpath() also can raise FileNotFoundError.

Updated patch attached.
-------------- next part --------------
diff --git a/check_libs_ng/check_libs_ng b/check_libs_ng/check_libs_ng
index f260491..d042326 100644
--- a/check_libs_ng/check_libs_ng
+++ b/check_libs_ng/check_libs_ng
@@ -61,15 +61,18 @@ def main():
             logger.debug('checking process %s', proc_name)
             os.chdir(os.path.join(proc, 'map_files'))
             for map_file in os.listdir('.'):
-                # all files in /map_files/ are absolute symlinks, so we don't need abspath()
-                real_map_file_path = os.path.realpath(map_file)
-                if not '/lib/' in real_map_file_path:
-                    logger.debug('skipping non-lib path %s', real_map_file_path)
-                    continue
-                else:
-                    logger.debug('checking lib %s', real_map_file_path)
-                if os.stat(map_file).st_nlink == 0:
-                    needs_reload.setdefault(proc_name, set()).add(proc_pid)
+                try:
+                    # all files in /map_files/ are absolute symlinks, so we don't need abspath()
+                    real_map_file_path = os.path.realpath(map_file)
+                    if not '/lib/' in real_map_file_path:
+                        logger.debug('skipping non-lib path %s', real_map_file_path)
+                        continue
+                    else:
+                        logger.debug('checking lib %s', real_map_file_path)
+                    if os.stat(map_file).st_nlink == 0:
+                        needs_reload.setdefault(proc_name, set()).add(proc_pid)
+                except FileNotFoundError:
+                    pass
         else:
             logger.debug('skipping kernel process %s', os.path.basename(proc))