remote: add build-derivation executable

cabal.project

@@ -20,4 +20,4 @@ package hnix-store-nar
   flags: +bounded_memory
 
 package hnix-store-remote
-  flags: +build-readme +io-testsuite
+  flags: +build-derivation +build-readme +io-testsuite

hnix-store-remote/app/BuildDerivation.hs

@@ -0,0 +1,41 @@
+{-# LANGUAGE LambdaCase #-}
+module Main where
+
+import Data.Default.Class (Default(def))
+import Data.Text (Text)
+import System.Nix.Derivation (Derivation)
+import System.Nix.StorePath (StorePath)
+
+import qualified Data.Text
+import qualified Data.Text.IO
+import qualified Data.Attoparsec.Text
+import qualified System.Environment
+import qualified System.Nix.Build
+import qualified System.Nix.Derivation
+import qualified System.Nix.StorePath
+import qualified System.Nix.Store.Remote
+
+parseDerivation :: FilePath -> IO (Derivation StorePath Text)
+parseDerivation source = do
+  contents <- Data.Text.IO.readFile source
+  case Data.Attoparsec.Text.parseOnly
+    (System.Nix.Derivation.parseDerivation def) contents of
+      Left e -> error e
+      Right drv -> pure drv
+
+main :: IO ()
+main = System.Environment.getArgs >>= \case
+  [filename] -> do
+    case System.Nix.StorePath.parsePathFromText def (Data.Text.pack filename) of
+      Left e -> error $ show e
+      Right p -> do
+        d <- parseDerivation filename
+        out <-
+            System.Nix.Store.Remote.runStore
+          $ System.Nix.Store.Remote.buildDerivation
+              p
+              d
+              System.Nix.Build.BuildMode_Normal
+        print out
+  _ -> error "No input derivation file"
+

hnix-store-remote/hnix-store-remote.cabal

@@ -56,6 +56,12 @@ flag io-testsuite
     Enable testsuite, which requires external
     binaries and Linux namespace support.
 
+flag build-derivation
+  default:
+    False
+  description:
+    Build build-derivation executable
+
 flag build-readme
   default:
     False
@@ -111,6 +117,21 @@ library
   hs-source-dirs:      src
   ghc-options:         -Wall
 
+executable build-derivation
+  if !flag(build-derivation)
+    buildable: False
+  build-depends:
+      base >=4.12 && <5
+    , attoparsec
+    , hnix-store-core
+    , hnix-store-remote
+    , data-default-class
+    , text
+  default-language: Haskell2010
+  main-is: BuildDerivation.hs
+  hs-source-dirs:      app
+  ghc-options: -Wall -threaded -rtsopts "-with-rtsopts -N"
+
 executable remote-readme
   if !flag(build-readme)
     buildable: False