Interpolate boolean env vars from conf file (#897)

CHANGELOG.md

@@ -11,6 +11,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- #896, Boolean env var interpolation in config file - @begriffs
+
 ## [0.4.2.0] - 2017-06-11
 
 ### Added

src/PostgREST/Config.hs

@@ -111,7 +111,7 @@ readOptions = do
           <*> (fromMaybe "*4" <$> C.key "server-host")
           <*> (fromMaybe 3000 . join . fmap coerceInt <$> C.key "server-port")
           <*> (fmap encodeUtf8 . mfilter (/= "") <$> C.key "jwt-secret")
-          <*> (fromMaybe False <$> C.key "secret-is-base64")
+          <*> (fromMaybe False . join . fmap coerceBool <$> C.key "secret-is-base64")
           <*> (fromMaybe 10 . join . fmap coerceInt <$> C.key "db-pool")
           <*> (join . fmap coerceInt <$> C.key "max-rows")
           <*> C.key "pre-request"
@@ -130,6 +130,11 @@ readOptions = do
   coerceInt (String x) = readMaybe $ toS x
   coerceInt _ = Nothing
 
+  coerceBool ::  Value -> Maybe Bool
+  coerceBool (Bool b) = Just b
+  coerceBool (String x) = readMaybe $ toS x
+  coerceBool _ = Nothing
+
   opts = info (helper <*> pathParser) $
            fullDesc
            <> progDesc (