From 93b341c7ab968aedd926ed30cfbd3fa29be62fb3 Mon Sep 17 00:00:00 2001
From: Brett Holman <brett.holman@canonical.com>
Date: Fri, 5 Aug 2022 18:11:06 +0200
Subject: [PATCH 1/3] util: Fix error path and parsing in get_proc_ppid()

Reference:https://github.com/canonical/cloud-init/commit/668a68fe577368555ea7f71577fc352494a98c25
Conflict:NA

If IOError was thrown, the variable "contents" was
unbound and threw a name error exception.

Parsing /proc/<num>/stat was broken in less common
cases.

Fix both and add parsing tests.
---
 cloudinit/util.py            | 10 ++++-----
 tests/unittests/test_util.py | 41 ++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/cloudinit/util.py b/cloudinit/util.py
index 0e0fc04..9e530db 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -2761,13 +2761,13 @@ def get_proc_ppid(pid):
     ppid = 0
     try:
         contents = load_file("/proc/%s/stat" % pid, quiet=True)
+        if contents:
+            # see proc.5 for format
+            m = re.search(r"^\d+ \(.+\) [RSDZTtWXxKWP] (\d+)", str(contents))
+            if m:
+                ppid = int(m.group(1))
     except IOError as e:
         LOG.warning('Failed to load /proc/%s/stat. %s', pid, e)
-    if contents:
-        parts = contents.split(" ", 4)
-        # man proc says
-        #  ppid %d     (4) The PID of the parent.
-        ppid = int(parts[3])
     return ppid
 
 # vi: ts=4 expandtab
diff --git a/tests/unittests/test_util.py b/tests/unittests/test_util.py
index 1185487..3fa5059 100644
--- a/tests/unittests/test_util.py
+++ b/tests/unittests/test_util.py
@@ -898,6 +898,47 @@ class TestGetProcEnv(helpers.TestCase):
         my_ppid = os.getppid()
         self.assertEqual(my_ppid, util.get_proc_ppid(my_pid))
 
+    def test_get_proc_ppid_mocked(self):
+        for ppid, proc_data in (
+            (
+                0,
+                "1 (systemd) S 0 1 1 0 -1 4194560 112664 14612195 153 18014"
+                "274 237 756828 152754 20 0 1 0 3 173809664 3736"
+                "18446744073709551615 1 1 0 0 0 0 671173123 4096 1260 0 0 0 17"
+                "8 0 0 0 0 123974 0 0 0 0 0 0 0 0",
+            ),
+            (
+                180771,
+                "180781 ([pytest-xdist r) R 180771 180598 167240 34825 "
+                "180598 4194304 128712 7570 0 0 1061 34 8 1 20 0 2 0 6551540 "
+                "351993856 25173 18446744073709551615 93907896635392 "
+                "93907899455533 140725724279536 0 0 0 0 16781312 17642 0 0 0 "
+                "17 1 0 0 0 0 0 93907901810800 93907902095288 93907928788992 "
+                "140725724288007 140725724288074 140725724288074 "
+                "140725724291047 0",
+            ),
+            (
+                5620,
+                "8723 (Utility Process) S 5620 5191 5191 0 -1 4194304 3219 "
+                "0 50 0 1045 431 0 0 20 0 3 0 9007 220585984 8758 "
+                "18446744073709551615 94469734690816 94469735319392 "
+                "140728350183632 0 0 0 0 69634 1073745144 0 0 0 17 10 0 0 0 0 "
+                "0 94469735327152 94469735331056 94469763170304 "
+                "140728350189012 140728350189221 140728350189221 "
+                "140728350195661 0",
+            ),
+            (
+                4946,
+                "4947 ((sd-pam)) S 4946 4946 4946 0 -1 1077936448 54 0 0 0 "
+                "0 0 0 0 20 0 1 0 4136 175616000 1394 18446744073709551615 1 1"
+                "0 0 0 0 0 4096 0 0 0 0 17 8 0 0 0 0 0 0 0 0 0 0 0 0 0",
+            ),
+        ):
+            with mock.patch(
+                "cloudinit.util.load_file", return_value=proc_data
+            ):
+                assert ppid == util.get_proc_ppid("mocked")
+
 
 class TestKernelVersion():
     """test kernel version function"""
-- 
2.40.0