IPMI driver (bug fixes).

Change-Id: Iceb368e6882cc34029e9488bc3425f1321e62903

kwapi/drivers/ipmi.py

@@ -14,6 +14,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import errno
+import os
 import subprocess
 import time
 import uuid
@@ -35,32 +37,47 @@ class Ipmi(Driver):
 
         """
         Driver.__init__(self, probe_ids, kwargs)
-        self.cache_file = kwargs.get('cache_directory') + '/' +
-        str(uuid.uuid5(uuid.NAMESPACE_DNS, probe_ids[0]))
-        command = 'ipmitool '
-        command += '-I ' + kwargs.get('interface') + ' '
-        command += '-H ' + kwargs.get('host') + ' '
-        command += '-U ' + kwargs.get('username', 'root') + ' '
-        command += '-P ' + kwargs.get('password') + ' '
-        command += 'sdr dump ' + cache_file
-        output, error = subprocess.Popen(command,
-                                         shell=True,
-                                         stdout=subprocess.PIPE,
-                                         stderr=subprocess.STDOUT
-                                         ).communicate()
 
     def run(self):
         """Starts the driver thread."""
+        self.create_cache()
         while not self.stop_request_pending():
             measurements = {}
             measurements['w'] = self.get_watts()
             self.send_measurements(self.probe_ids[0], measurements)
             time.sleep(1)
 
+    def get_cache_filename(self):
+        """Returns the cache filename."""
+        return self.kwargs.get('cache_dir') + '/' + \
+            str(uuid.uuid5(uuid.NAMESPACE_DNS, self.probe_ids[0]))
+
+    def create_cache(self):
+        """Creates the cache file."""
+        try:
+            os.makedirs(self.kwargs.get('cache_dir'))
+        except OSError as exception:
+            if exception.errno != errno.EEXIST:
+                raise
+        command = 'ipmitool '
+        command += '-I ' + self.kwargs.get('interface') + ' '
+        command += '-H ' + self.kwargs.get('host') + ' '
+        command += '-U ' + self.kwargs.get('username', 'root') + ' '
+        command += '-P ' + self.kwargs.get('password') + ' '
+        command += 'sdr dump ' + self.get_cache_filename()
+        output, error = subprocess.Popen(command,
+                                         shell=True,
+                                         stdout=subprocess.PIPE,
+                                         stderr=subprocess.STDOUT
+                                         ).communicate()
+
     def get_watts(self):
         """Returns the power consumption."""
+        cache_file = self.get_cache_filename()
+        if not os.path.exists(cache_file):
+            self.create_cache()
         command = 'ipmitool '
-        command += '-S ' + self.cache_file + ' '
+        command += '-S ' + cache_file + ' '
         command += '-I ' + self.kwargs.get('interface') + ' '
         command += '-H ' + self.kwargs.get('host') + ' '
         command += '-U ' + self.kwargs.get('username', 'root') + ' '