Add CLI and configurable configuration

README.md

@@ -2,10 +2,15 @@
 
 Arbitrary code execution server using Docker.  
 
-## Setup
+## Install
 
-- Fill out `config.dhall`, read it for documentation and an example
-- Run `stack run`
+- Install [Stack 2+](https://docs.haskellstack.org/en/stable/README/)
+- Run `stack install`, a `myriad` executable will be installed
+
+## Running
+
+- Make sure the configuration is filled out, see `config.dhall` for an example
+- Run `myriad --config path/to/config.dhall`
 
 ## Endpoints
 

package.yaml

@@ -25,6 +25,7 @@ dependencies:
 - monad-control
 - monad-logger
 - mtl
+- optparse-applicative
 - servant
 - servant-server
 - snowflake

src/Main.hs

@@ -2,15 +2,33 @@ module Main where
 
 import Control.Monad.Logger
 
+import qualified Data.Text as T
+import Options.Applicative
+
 import Network.Wai.Handler.Warp (run)
 
 import Myriad.Core
 import Myriad.Docker
 import Myriad.Server
 
+data Args = Args
+    { configInput :: T.Text
+    }
+
+parseArgs :: IO Args
+parseArgs = execParser $ info (helper <*> args) (fullDesc <> progDesc "Run the Myriad server")
+    where
+        args = Args <$> option str (mconcat
+            [ long "config"
+            , short 'c'
+            , help "Sets the Dhall configuration"
+            , metavar "DHALL"
+            ])
+
 main :: IO ()
 main = do
-    env <- initEnv "./config.dhall"
+    Args { configInput } <- parseArgs
+    env <- initEnv configInput
     runMyriadT env do
         buildAllImages
         startCleanup

src/Myriad/Core.hs

@@ -67,12 +67,12 @@ type MyriadT m = ReaderT Env (LoggingT m)
 type MonadWithIO m = (MonadIO m, MonadBase IO m, MonadBaseControl IO m)
 
 readConfig :: T.Text -> IO MyriadConfig
-readConfig path = input auto path
+readConfig = input auto
 
 initEnv :: T.Text -> IO Env
-initEnv path =
+initEnv configInput =
         Env
-    <$> readConfig path
+    <$> readConfig configInput
     <*> newIORef M.empty
     <*> newIORef M.empty
     <*> newIORef M.empty