utils.abs_readlink: return abs path, dereference symlinks

salt/utils/__init__.py

@@ -858,6 +858,41 @@ def path_join(*parts):
     ))
 
 
+def abs_readlink(path):
+    '''
+    Return the absolute path.  If path is a link, dereference it first.
+
+    .. code-block:: python
+
+        >>> import os
+        >>> os.makedirs('/tmp/dir')
+        >>> os.chdir('/tmp/dir')
+        >>> open('/tmp/dir/target', 'w').close()
+        >>> os.symlink('target', 'link1')
+        >>> os.symlink('../dir/target', 'link2')
+        >>> os.symlink('/tmp/dir/target', 'link3')
+        >>> abs_readlink('/tmp/dir/target')
+        '/tmp/dir/target'
+        >>> abs_readlink('/tmp/dir/link1')
+        '/tmp/dir/target'
+        >>> abs_readlink('/tmp/dir/link2')
+        '/tmp/dir/target'
+        >>> abs_readlink('/tmp/dir/link3')
+        '/tmp/dir/target'
+        >>> from subprocess import call
+        >>> call(['rm', '-r', '/tmp/dir'])
+    '''
+    if os.path.islink(path):
+        base, lname = os.path.split(os.path.abspath(path))
+        target = os.readlink(path)
+        if target.startswith(os.sep):
+            return os.path.abspath(target)
+        else:  # target path is relative to supplied path
+            return os.path.abspath(os.path.join(base, target))
+    else:
+        return os.path.abspath(path)
+
+
 def pem_finger(path=None, key=None, sum_type='sha256'):
     '''
     Pass in either a raw pem string, or the path on disk to the location of a