piggy-back

Main.hs

{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE StrictData #-}
module Constellation.Node.Main where

import ClassyPrelude hiding (getArgs, log)
import Control.Concurrent (forkIO)
import Control.Logging
    ( LogLevel(LevelDebug, LevelInfo, LevelWarn, LevelError)
    , setLogLevel, withStderrLogging, log', errorL'
    )
import Data.Text.Format (Shown(Shown))
import GHC.Conc (getNumProcessors)
import Network.Socket
    ( Family(AF_UNIX), SocketType(Stream), SockAddr(SockAddrUnix)
    , socket, bind, listen, maxListenQueue, close
    )
import System.Directory (doesFileExist, removeFile)
import System.Environment (getArgs)
import qualified Data.Text as T
import qualified Network.Wai.Handler.Warp as Warp

import Constellation.Enclave
    (newEnclave', enclaveEncryptPayload, enclaveDecryptPayload)
import Constellation.Enclave.Key (mustLoadKeyPairs, mustLoadPublicKeys)
import Constellation.Enclave.Keygen.Main (generateKeyPair)
import Constellation.Node (newNode, runNode)
import Constellation.Node.Storage.BerkeleyDb (berkeleyDbStorage)
import Constellation.Node.Storage.Directory (directoryStorage)
import Constellation.Node.Storage.LevelDb (levelDbStorage)
import Constellation.Node.Storage.Memory (memoryStorage)
import Constellation.Node.Storage.Sqlite (sqliteStorage)
import Constellation.Node.Types
    ( Node(nodeStorage)
    , Crypt(Crypt, encryptPayload, decryptPayload)
    , Storage(closeStorage)
    )
import Constellation.Node.Config (Config(..), extractConfig)
import Constellation.Util.AtExit (registerAtExit, withAtExit)
import Constellation.Util.Logging (debugf', logf', warnf)
import qualified Constellation.Node.Api as NodeApi

version :: Text
version = "0.1.0"

defaultMain :: IO ()
defaultMain = do
    args     <- getArgs
    (cfg, _) <- extractConfig args
    if cfgJustShowVersion cfg
        then putStrLn ("Constellation Node " ++ version)
        else case cfgJustGenerateKeys cfg of
                 [] -> withStderrLogging $ run cfg
                 ks -> mapM_ generateKeyPair ks

run :: Config -> IO ()
run cfg@Config{..} = do
    let logLevel = case cfgVerbosity of
            0 -> LevelError
            1 -> LevelWarn
            2 -> LevelInfo
            3 -> LevelDebug
            _ -> LevelDebug
    logf' "Log level is {}" [show logLevel]
    setLogLevel logLevel
    debugf' "Configuration: {}" [show cfg]
    ncpus <- getNumProcessors
    logf' "Utilizing {} core(s)" [ncpus]
    setNumCapabilities ncpus
    pwds <- case cfgPasswords of
        Just passPath -> do
               checkForAFile passPath
                (map (Just . T.unpack) . lines) <$> readFileUtf8 passPath
        Nothing       -> return $ replicate (length cfgPublicKeys) Nothing
    when (length cfgPublicKeys /= length cfgPrivateKeys) $
        errorL' "The same amount of public keys and private keys must be specified"
    when (length cfgPublicKeys /= length pwds) $
        errorL' "The same amount of passwords must be included in the passwords file as the number of private keys. (If a private key has no password, include a blank line.)"
    when (cfgPort == 0) $
        errorL' "A listening port must be specified with 'port' in the configuration file or --port at runtime"
    let kps = zip3 cfgPublicKeys cfgPrivateKeys pwds
    logf' "Constructing Enclave using keypairs {}"
        [show $ zip cfgPublicKeys cfgPrivateKeys]
    ks <- mustLoadKeyPairs kps
    e  <- newEnclave' ks
    let crypt = Crypt
            { encryptPayload = enclaveEncryptPayload e
            , decryptPayload = enclaveDecryptPayload e
            }
    ast <- mustLoadPublicKeys cfgAlwaysSendTo
    logf' "Initializing storage {}" [cfgStorage]
    let experimentalStorageCaveat s = warnf "The {} storage engine is experimental. It may be removed or changed at any time. Please see the discussion at https://github.com/jpmorganchase/constellation/issues/37" [s :: Text]
    storage <- case break (== ':') cfgStorage of
        ("bdb",     ':':path) -> berkeleyDbStorage path
        ("dir",     ':':path) -> directoryStorage path
        ("leveldb", ':':path) -> experimentalStorageCaveat "LevelDB"
            >> levelDbStorage path
        ("memory",  _       ) -> memoryStorage
        ("sqlite",  ':':path) -> experimentalStorageCaveat "SQLite"
            >> sqliteStorage path
        _                     -> berkeleyDbStorage cfgStorage  -- Default
    nvar    <- newTVarIO =<<
        newNode crypt storage cfgUrl (map fst ks) ast cfgOtherNodes
    _ <- forkIO $ do
        let mwl = if null cfgIpWhitelist
                then Nothing
                else Just $ NodeApi.whitelist cfgIpWhitelist
        logf' "Public API listening on 0.0.0.0 port {} with whitelist: {}"
            ( cfgPort
            , Shown $ if isNothing mwl then ["Disabled"] else cfgIpWhitelist
            )
        Warp.run cfgPort $ NodeApi.app mwl NodeApi.Public nvar
    _ <- case cfgSocket of
        Just sockPath -> void $ forkIO $ do
            logf' "Internal API listening on {}" [sockPath]
            resetSocket sockPath
            sock <- socket AF_UNIX Stream 0
            bind sock $ SockAddrUnix sockPath
            listen sock maxListenQueue
            Warp.runSettingsSocket Warp.defaultSettings sock $
                NodeApi.app Nothing NodeApi.Private nvar
            close sock
        Nothing       -> return ()
    registerAtExit $ do
        log' "Shutting down... (Interrupting this will cause the next startup to take longer)"
        case cfgSocket of
            Just sockPath -> resetSocket sockPath
            Nothing       -> return ()
        readTVarIO nvar >>= closeStorage . nodeStorage
    log' "Node started"
    withAtExit $ runNode nvar

resetSocket :: FilePath -> IO ()
resetSocket sockPath = doesFileExist sockPath >>= \exists ->
    when exists $ removeFile sockPath

checkForAFile :: FilePath -> IO ()
checkForAFile path = do
    validFile <- doesFileExist path
    if validFile
       then putStrLn $ path ++ " is a file that exists"
       else putStrLn $ path ++ " is not a file that exists"

A few things happening here.
One is that the indentation on the line calling readFileUtf8 is all screwy. It's a little bit too far to the right. Line it up so that the parens beginning that line is in the same column as the c beginning checkForAFile.

The way it's spaced currently, GHC thinks you're trying to pass that whole line as an argument to checkForAFile, which only has one arg, so it gets confused and you get a type error.

The second error is because passPath is of type String, and something expects type Text. I think you're running into this error because the author hid the default prelude and imported Classy Prelude instead, which has some compat issues that creep up, like this one.

Not a big deal, you can use the pack function from Data.Text to convert, as it has type String -> Text. In this code, Data.Text has been imported as a qualified import to T, so you can get to it's functions by prefixing them with T..

There is a cool haskell search engine called hoogle that let's you search for things by type signature that you can use if you run into that sort of problem.

On mobile right now, so can't post examples, hopefully that's enough for you to go on.