Export the data collected by DRBD in JSON format

Write an intermediate function computing the JSON data before adding them
to the DCReport.

Directly export the data computed by that function (with default parameters)
allowing them to be used (in the future) by the monitoring agent.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Bernardo Dal Seno <bdalseno@google.com>

src/Ganeti/DataCollectors/Drbd.hs

@@ -32,6 +32,7 @@ module Ganeti.DataCollectors.Drbd
   , dcFormatVersion
   , dcCategory
   , dcKind
+  , dcData
   ) where
 
 
@@ -87,6 +88,10 @@ dcCategory = Just DCStorage
 dcKind :: DCKind
 dcKind = DCKStatus
 
+-- | The data exported by the data collector, taken from the default location.
+dcData :: IO J.JSValue
+dcData = buildJsonReport defaultFile Nothing
+
 -- * Command line options
 
 options :: IO [OptType]
@@ -121,21 +126,19 @@ getPairingInfo (Just filename) = do
       J.Ok instMinor -> BT.Ok instMinor
       J.Error msg -> BT.Bad msg
 
--- | This function builds a report with the DRBD status.
-buildDRBDReport :: FilePath -> Maybe FilePath -> IO DCReport
-buildDRBDReport statusFile pairingFile = do
+-- | This function computes the JSON representation of the DRBD status.
+buildJsonReport :: FilePath -> Maybe FilePath -> IO J.JSValue
+buildJsonReport statusFile pairingFile = do
   contents <-
     ((E.try $ readFile statusFile) :: IO (Either IOError String)) >>=
       exitIfBad "reading from file" . either (BT.Bad . show) BT.Ok
   pairingResult <- getPairingInfo pairingFile
   pairing <- exitIfBad "Can't get pairing info" pairingResult
-  jsonData <-
-    case A.parse (drbdStatusParser pairing) $ pack contents of
-      A.Fail unparsedText contexts errorMessage -> exitErr $
-        show (Prelude.take defaultCharNum $ unpack unparsedText) ++ "\n"
-          ++ show contexts ++ "\n" ++ errorMessage
-      A.Done _ drbdStatus -> return $ J.showJSON drbdStatus
-  buildReport dcName dcVersion dcFormatVersion dcCategory dcKind jsonData
+  case A.parse (drbdStatusParser pairing) $ pack contents of
+    A.Fail unparsedText contexts errorMessage -> exitErr $
+      show (Prelude.take defaultCharNum $ unpack unparsedText) ++ "\n"
+        ++ show contexts ++ "\n" ++ errorMessage
+    A.Done _ drbdStatus -> return $ J.showJSON drbdStatus
 
 -- | Main function.
 main :: Options -> [String] -> IO ()
@@ -144,5 +147,6 @@ main opts args = do
       pairingFile = optDrbdPairing opts
   unless (null args) . exitErr $ "This program takes exactly zero" ++
                                   " arguments, got '" ++ unwords args ++ "'"
-  report <- buildDRBDReport statusFile pairingFile
+  report <- buildJsonReport statusFile pairingFile >>=
+    buildReport dcName dcVersion dcFormatVersion dcCategory dcKind
   putStrLn $ J.encode report