From 89cb898ac3d3164ff0891c4e715ada49ede23b98 Mon Sep 17 00:00:00 2001
From: Hans Krijger <hglkrijger@users.noreply.github.com>
Date: Mon, 6 Jun 2016 11:48:21 -0700
Subject: [PATCH] check for existence before chmod/chown/chcon (#206)

code review feedback
---
 azurelinuxagent/common/osutil/default.py |  5 ++++-
 azurelinuxagent/common/utils/fileutil.py | 12 +++++++++---
 bin/waagent2.0                           |  8 +++++++-
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/azurelinuxagent/common/osutil/default.py b/azurelinuxagent/common/osutil/default.py
index 0efd8ee..577e0e5 100644
--- a/azurelinuxagent/common/osutil/default.py
+++ b/azurelinuxagent/common/osutil/default.py
@@ -194,7 +194,7 @@ class DefaultOSUtil(object):
         """
         path, thumbprint, value = pubkey
         if path is None:
-            raise OSUtilError("Publich key path is None")
+            raise OSUtilError("Public key path is None")
 
         crytputil = CryptUtil(conf.get_openssl_cmd())
 
@@ -261,6 +261,9 @@ class DefaultOSUtil(object):
         Returns exit result.
         """
         if self.is_selinux_system():
+            if not os.path.exists(path):
+                logger.error("Path does not exist: {0}".format(path))
+                return 1
             return shellutil.run('chcon ' + con + ' ' + path)
 
     def conf_sshd(self, disable_password):
diff --git a/azurelinuxagent/common/utils/fileutil.py b/azurelinuxagent/common/utils/fileutil.py
index 24842d0..c476129 100644
--- a/azurelinuxagent/common/utils/fileutil.py
+++ b/azurelinuxagent/common/utils/fileutil.py
@@ -91,11 +91,17 @@ def mkdir(dirpath, mode=None, owner=None):
         chowner(dirpath, owner)
 
 def chowner(path, owner):
-    owner_info = pwd.getpwnam(owner)
-    os.chown(path, owner_info[2], owner_info[3])
+    if not os.path.exists(path):
+        logger.error("Path does not exist: {0}".format(path))
+    else:
+        owner_info = pwd.getpwnam(owner)
+        os.chown(path, owner_info[2], owner_info[3])
 
 def chmod(path, mode):
-    os.chmod(path, mode)
+    if not os.path.exists(path):
+        logger.error("Path does not exist: {0}".format(path))
+    else:
+        os.chmod(path, mode)
 
 def rm_files(*args):
     for path in args:
diff --git a/bin/waagent2.0 b/bin/waagent2.0
index f3c9d71..6178d9f 100644
--- a/bin/waagent2.0
+++ b/bin/waagent2.0
@@ -228,6 +228,9 @@ class AbstractDistro(object):
         Returns exit result.
         """
         if self.isSelinuxSystem():
+            if not os.path.exists(path):
+                Error("Path does not exist: {0}".format(path))
+                return 1
             return Run('chcon ' + cn + ' ' + path)
         
     def setHostname(self,name):
@@ -2336,7 +2339,10 @@ def ChangeOwner(filepath, user):
     except:
         pass
     if p != None:
-        os.chown(filepath, p[2], p[3])
+        if not os.path.exists(filepath):
+            Error("Path does not exist: {0}".format(filepath))
+        else:
+            os.chown(filepath, p[2], p[3])
 
 def CreateDir(dirpath, user, mode):
     """