Pass from file

config.dhall

@@ -3,7 +3,7 @@ let config = ./dhall/package.dhall
 in    { amqp = config.AMQP::{
         , vhost = "reddit"
         , username = env:AMQP_USER as Text ? "reddit_pub"
-        , password = env:AMQP_PASS as Text ? "tester"
+        , password = config.Password.Type.Password (env:AMQP_PASS as Text ? "tester")
         , host = env:AMQP_HOST as Text ? "127.0.0.1"
         -- , host = "10.233.5.2"
         }

dhall/AMQP/Type.dhall

@@ -1,5 +1,5 @@
 { vhost : Text
 , username : Text
-, password : Text
+, password : ../Password/Type.dhall
 , host : Text
 }

dhall/Password/Type.dhall

@@ -0,0 +1 @@
+< Password : Text | File : Text >

dhall/Password/package.dhall

@@ -0,0 +1 @@
+{ Type = ./Type.dhall }

dhall/package.dhall

@@ -2,4 +2,5 @@
 , default = ./default.dhall
 , AMQP = ./AMQP/package.dhall
 , Fetcher = ./Fetcher/package.dhall
+, Password = ./Password/package.dhall
 }

src/Data/Config.hs

@@ -11,10 +11,17 @@ import Dhall.Deriving
 import Numeric.Natural (Natural)
 import Data.SubReddit (SubReddit)
 
+data Password
+  = Password Text
+  | File FilePath
+  deriving stock (Generic, Show)
+  deriving (FromDhall, ToDhall)
+    via (Codec AsIs Password)
+
 data AMQP = AMQP
   { amqpVhost :: Text
   , amqpUsername :: Text
-  , amqpPassword :: Text
+  , amqpPassword :: Password
   , amqpHost :: Text
   }
   deriving stock (Generic, Show)
@@ -30,7 +37,7 @@ vhost = lens amqpVhost (\ am txt -> am{amqpVhost=txt})
 username :: Lens' AMQP Text
 username = lens amqpUsername (\ am txt -> am{amqpUsername=txt})
 
-password :: Lens' AMQP Text
+password :: Lens' AMQP Password
 password = lens amqpPassword (\ am txt -> am{amqpPassword=txt})
 
 data Fetcher = Fetcher

src/MyLib.hs

@@ -35,6 +35,7 @@ import Network.Wreq.Session (newSession)
 import Publish (Publish(..))
 import Data.Aeson.Lens (key, _String)
 import Data.Bool (bool)
+import qualified Data.Text.IO as TI
 
 data MessageType = Create | Update
   deriving stock (Show, Eq, Generic)
@@ -70,11 +71,12 @@ amqpPublisher sqlConn channel exchange = Publish $ \msg -> do
 defaultMain :: FilePath -> IO ()
 defaultMain path = do
   conf <- readConfig path
+  pass <- getPassword (conf ^. amqp . password)
   let rabbitConnect = openConnection
                   (conf ^. amqp . host . T.unpacked)
                   (conf ^. amqp . vhost)
                   (conf ^. amqp . username)
-                  (conf ^. amqp . password)
+                  pass
   bracket rabbitConnect closeConnection $ \conn -> do
     SQL.withConnection (conf ^. sqlite) $ \sqlConn -> do
       SQL.execute_ sqlConn "create table if not exists membership (reddit_id primary key)"
@@ -87,3 +89,7 @@ defaultMain path = do
       for_ (conf ^. fetchers) $ \fetcher -> do
         print fetcher
         publishEntries (toMessage >$< publisher) sess fetcher
+
+getPassword :: Password -> IO Text
+getPassword (Password p) = pure p
+getPassword (File path) = TI.readFile path