From 8220d57690886dfffa252e99381bbdfd577db413 Mon Sep 17 00:00:00 2001
From: Michael DeHaan <michael.dehaan@gmail.com>
Date: Sat, 7 Jul 2012 08:45:06 -0400
Subject: [PATCH] Clean up md5 functions + make the fetch module stay happy if
 the remote file does not exist.

---
 lib/ansible/runner/__init__.py | 30 ++++++++++++++++++++++++------
 lib/ansible/utils.py           | 16 ++++++++++++++++
 2 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/lib/ansible/runner/__init__.py b/lib/ansible/runner/__init__.py
index aba6397bb70..1088f7c2f5e 100644
--- a/lib/ansible/runner/__init__.py
+++ b/lib/ansible/runner/__init__.py
@@ -481,19 +481,20 @@ class Runner(object):
         dest   = dest.replace("//","/")
 
         # compare old and new md5 for support of change hooks
-        local_md5 = None
-        if os.path.exists(dest):
-            local_md5 = os.popen("/usr/bin/md5sum %(file)s 2> /dev/null || /sbin/md5 -q %(file)s" % {"file": dest}).read().split()[0]
-        remote_md5 = self._low_level_exec_command(conn, "/usr/bin/md5sum %(file)s 2> /dev/null || /sbin/md5 -q %(file)s" % {"file": source}, tmp, True).split()[0]
+        local_md5 = utils.local_md5(dest)
+        remote_md5 = self._remote_md5(conn, tmp, source)
 
-        if remote_md5 != local_md5:
+        if remote_md5 == '0':
+            result = dict(msg="missing remote file", changed=False)
+            return ReturnData(host=conn.host, result=result)
+        elif remote_md5 != local_md5:
             # create the containing directories, if needed
             if not os.path.isdir(os.path.dirname(dest)):
                 os.makedirs(os.path.dirname(dest))
 
             # fetch the file and check for changes
             conn.fetch_file(source, dest)
-            new_md5 = os.popen("/usr/bin/md5sum %(file)s 2> /dev/null || /sbin/md5 -q %(file)s" % {"file": dest}).read().split()[0]
+            new_md5 = utils.local_md5(dest)
             if new_md5 != remote_md5:
                 result = dict(failed=True, msg="md5 mismatch", md5sum=new_md5)
                 return ReturnData(host=conn.host, result=result)
@@ -723,6 +724,23 @@ class Runner(object):
 
     # *****************************************************
 
+    def _remote_md5(self, conn, tmp, path):
+        ''' 
+        takes a remote md5sum without requiring python, and returns 0 if the
+        file does not exist
+        '''
+        test = "[[ -r %s ]]" % path
+        md5s = [
+            "(%s && /usr/bin/md5sum %s 2>/dev/null)" % (test,path),
+            "(%s && /sbin/md5sum -q %s 2>/dev/null)" % (test,path)
+        ]
+        cmd = " || ".join(md5s)
+        cmd = "%s || (echo \"0 %s\")" % (cmd, path)
+        remote_md5 = self._low_level_exec_command(conn, cmd, tmp, True).split()[0]
+        return remote_md5
+
+    # *****************************************************
+
     def _make_tmp_path(self, conn):
         ''' make and return a temporary path on a remote box '''
 
diff --git a/lib/ansible/utils.py b/lib/ansible/utils.py
index 5dc8c8349ee..d54d00042bf 100644
--- a/lib/ansible/utils.py
+++ b/lib/ansible/utils.py
@@ -312,6 +312,22 @@ def parse_kv(args):
                 options[k]=v
     return options
 
+def local_md5(file):
+     ''' compute local md5sum, return None if file is not present '''
+     cmd = "/usr/bin/md5sum %s 2> /dev/null || /sbin/md5 -q %s" % (file,file)
+     if not os.path.exists(file):
+         return None
+     else:
+         c = os.popen(cmd)
+         return c.read().split()[0]
+
+
+####################################################################
+# option handling code for /usr/bin/ansible and ansible-playbook 
+# below this line
+
+# FIXME: move to seperate file
+
 class SortedOptParser(optparse.OptionParser):
     '''Optparser which sorts the options by opt before outputting --help'''
     def format_help(self, formatter=None):