Support sudoers in the "usr merge" location

With the usr merge effort many configuration files are moving from /etc to
/usr/etc clearing the way for the /etc directory to be a space managed
by the system administrator and the /usr/etc space used by the distribution
vendor. Support the /usr/etc/sudoers location when managing the sudoers file.

cloudinit/distros/__init__.py

@@ -1006,14 +1006,20 @@ def write_doas_rules(self, user, rules, doas_file=None):
                     )
                     raise e
 
-    def ensure_sudo_dir(self, path, sudo_base="/etc/sudoers"):
+    def ensure_sudo_dir(
+            self, path, sudo_base=("/etc/sudoers","/usr/etc/sudoers")):
         # Ensure the dir is included and that
         # it actually exists as a directory
         sudoers_contents = ""
         base_exists = False
-        if os.path.exists(sudo_base):
-            sudoers_contents = util.load_text_file(sudo_base)
-            base_exists = True
+        admin_sudo_base = "/etc/sudoers"
+        if not isinstance(sudo_base, (list, tuple)):
+            sudo_base = [sudo_base]
+        for sudoers_base in sudo_base:
+            if os.path.exists(sudoers_base):
+                sudoers_contents = util.load_text_file(sudoers_base)
+                base_exists = True
+                break
         found_include = False
         for line in sudoers_contents.splitlines():
             line = line.strip()
@@ -1039,19 +1045,22 @@ def ensure_sudo_dir(self, path, sudo_base="/etc/sudoers"):
                         "",
                     ]
                     sudoers_contents = "\n".join(lines)
-                    util.write_file(sudo_base, sudoers_contents, 0o440)
+                    util.write_file(admin_sudo_base, sudoers_contents, 0o440)
                 else:
+                    if sudoers_base != admin_sudo_base:
+                        util.write_file(
+                            admin_sudo_base, sudoers_contents, 0o440)
                     lines = [
                         "",
                         util.make_header(base="added"),
                         "#includedir %s" % (path),
                         "",
                     ]
                     sudoers_contents = "\n".join(lines)
-                    util.append_file(sudo_base, sudoers_contents)
-                LOG.debug("Added '#includedir %s' to %s", path, sudo_base)
+                    util.append_file(admin_sudo_base, sudoers_contents)
+                LOG.debug("Added '#includedir %s' to %s", path, admin_sudo_base)
             except IOError as e:
-                util.logexc(LOG, "Failed to write %s", sudo_base)
+                util.logexc(LOG, "Failed to write %s", admin_sudo_base)
                 raise e
         util.ensure_dir(path, 0o750)
 

tests/unittests/distros/test__init__.py

@@ -232,6 +232,32 @@ def test_sudoers_ensure_append(self):
         self.assertIn("josh", contents)
         self.assertEqual(2, contents.count("josh"))
 
+    def test_sudoers_ensure_append_sudoer_file(self):
+        cls = distros.fetch("ubuntu")
+        d = cls("ubuntu", {}, None)
+        self.patchOS(self.tmp)
+        self.patchUtils(self.tmp)
+        util.write_file("/etc/sudoers", "josh, josh\n")
+        d.ensure_sudo_dir("/b", "/etc/sudoers")
+        contents = util.load_text_file("/etc/sudoers")
+        self.assertIn("includedir /b", contents)
+        self.assertTrue(os.path.isdir("/b"))
+        self.assertIn("josh", contents)
+        self.assertEqual(2, contents.count("josh"))
+
+    def test_usr_sudoers_ensure_append(self):
+        cls = distros.fetch("ubuntu")
+        d = cls("ubuntu", {}, None)
+        self.patchOS(self.tmp)
+        self.patchUtils(self.tmp)
+        util.write_file("/usr/etc/sudoers", "josh, josh\n")
+        d.ensure_sudo_dir("/b")
+        contents = util.load_text_file("/etc/sudoers")
+        self.assertIn("includedir /b", contents)
+        self.assertTrue(os.path.isdir("/b"))
+        self.assertIn("josh", contents)
+        self.assertEqual(2, contents.count("josh"))
+
     def test_sudoers_ensure_only_one_includedir(self):
         cls = distros.fetch("ubuntu")
         d = cls("ubuntu", {}, None)