Python3: Fix using dictionary keys()

It will throw TypeError when you try to operate on
dict.keys() like a list in python3.
ref:https://docs.python.org/3/library/stdtypes.html#dictionary-view-objects

Change-Id: I3f1173e74ddd589f3d363597bd1562299f92e93d

sahara/plugins/cdh/client/types.py

@@ -297,7 +297,7 @@ class BaseApiObject(object):
         Default implementation of __str__. Uses the type name and the first
         attribute retrieved from the attribute map to create the string.
         """
-        name = self._get_attributes().keys()[0]
+        name = list(self._get_attributes().keys())[0]
         value = getattr(self, name, None)
         return "<%s>: %s = %s" % (self.__class__.__name__, name, value)
 

sahara/plugins/hdp/ambariplugin.py

@@ -385,7 +385,8 @@ class AmbariPlugin(p.ProvisioningPluginBase):
 
         # results in validation
         handler.get_cluster_spec(
-            cluster, [], dict(existing.items() + additional.items()))
+            cluster, [],
+            dict(list(existing.items()) + list(additional.items())))
 
     def _get_num_hosts(self, cluster):
         count = 0

sahara/utils/patches.py

@@ -79,7 +79,7 @@ def patch_minidom_writexml():
         writer.write(indent + "<" + self.tagName)
 
         attrs = self._get_attributes()
-        a_names = attrs.keys()
+        a_names = list(attrs.keys())
         a_names.sort()
 
         for a_name in a_names:

sahara/utils/ssh_remote.py

@@ -751,7 +751,7 @@ class InstanceInteropHelper(remote.Remote):
         self._run_s(_write_file_to, timeout, remote_file, data, run_as_root)
 
     def write_files_to(self, files, run_as_root=False, timeout=None):
-        self._log_command('Writing files "%s"' % files.keys())
+        self._log_command('Writing files "%s"' % list(files.keys()))
         self._run_s(_write_files_to, timeout, files, run_as_root)
 
     def append_to_file(self, r_file, data, run_as_root=False, timeout=None):
@@ -759,7 +759,7 @@ class InstanceInteropHelper(remote.Remote):
         self._run_s(_append_to_file, timeout, r_file, data, run_as_root)
 
     def append_to_files(self, files, run_as_root=False, timeout=None):
-        self._log_command('Appending to files "%s"' % files.keys())
+        self._log_command('Appending to files "%s"' % list(files.keys()))
         self._run_s(_append_to_files, timeout, files, run_as_root)
 
     def read_file_from(self, remote_file, run_as_root=False, timeout=None):