StartAsNonProducingNode: configuration option

The configuration option `StartAsNonProducingNode` was ignored, one
could only use the switch `--non-producing-node` to set it.  In this
patch we fix this, and now it can be set either with the switch or if
it's not given, it can be set in the configuration file.

Author: coot

cardano-node/src/Cardano/Node/Configuration/POM.hs

@@ -314,6 +314,7 @@ instance Semigroup PartialNodeConfiguration where
 instance FromJSON PartialNodeConfiguration where
   parseJSON =
     withObject "PartialNodeConfiguration" $ \v -> do
+      pncStartAsNonProducingNode <- Last <$> v .:? "StartAsNonProducingNode"
 
       -- Node parameters, not protocol-specific
       pncSocketPath <- Last <$> v .:? "SocketPath"
@@ -435,7 +436,7 @@ instance FromJSON PartialNodeConfiguration where
            , pncProtocolFiles = mempty
            , pncValidateDB = mempty
            , pncShutdownConfig = mempty
-           , pncStartAsNonProducingNode = Last $ Just False
+           , pncStartAsNonProducingNode
            , pncMaybeMempoolCapacityOverride
            , pncLedgerDbConfig
            , pncProtocolIdleTimeout

cardano-node/src/Cardano/Node/Parsers.hs

@@ -27,8 +27,11 @@ import           Data.Foldable
 import           Data.Maybe (fromMaybe)
 import           Data.Monoid (Last (..))
 import           Data.Text (Text)
-import           Data.Word (Word32)
-import           Options.Applicative hiding (str)
+import qualified Data.Text as Text
+import           Data.Word (Word16, Word32)
+import           Options.Applicative hiding (str, switch)
+-- Don't use switch.  It will not allow to set an option in a configuration
+-- file.  See `parseStartAsNonProducingNode` and `parseValidateDB`.
 import qualified Options.Applicative as Opt
 import qualified Options.Applicative.Help as OptI
 import           System.Posix.Types (Fd (..))
@@ -60,7 +63,7 @@ nodeRunParser = do
   shelleyVRFFile  <- optional parseVrfKeyFilePath
   shelleyCertFile <- optional parseOperationalCertFilePath
   shelleyBulkCredsFile <- optional parseBulkCredsFilePath
-  startAsNonProducingNode <- lastOption parseStartAsNonProducingNode
+  startAsNonProducingNode <- Last <$> parseStartAsNonProducingNode
 
   -- Node Address
   nIPv4Address <- lastOption parseHostIPv4Addr
@@ -266,9 +269,13 @@ parseImmutableDbPath = strOption $
     ]
 
 
+-- | This parser will always override configuration option, even if the
+-- `--validate-db` is not present.  This is fine for `--validate-db` switch,
+-- but might not be for something else.  See `parseStartAsNonProducingNode` for
+-- an alternative solution.
 parseValidateDB :: Parser Bool
 parseValidateDB =
-    switch (
+    Opt.switch (
          long "validate-db"
       <> help "Validate all on-disk database files"
     )
@@ -353,9 +360,12 @@ parseVrfKeyFilePath =
         <> completer (bashCompleter "file")
     )
 
-parseStartAsNonProducingNode :: Parser Bool
+-- | A parser which returns `Nothing` or `Just True`; the default value is set
+-- in `defaultPartialNodeConfiguration`.  This allows to set this option either
+-- in the configuration file or as command line flag.
+parseStartAsNonProducingNode :: Parser (Maybe Bool)
 parseStartAsNonProducingNode =
-  switch $ mconcat
+  flag Nothing (Just True) $ mconcat
     [ long "non-producing-node"
     , help $ mconcat
         [ "Start the node as a non block producing node even if "