pp: Add automatic launcher

garlic/index.nix

@@ -118,6 +118,10 @@
     # Takes a list of experiments and returns a file that contains
     # all timetable results from the experiments.
     merge = exps: mergeDatasets (map timetableFromTrebuchet exps);
+
+    # Automatic launcher
+    launcher = callPackage ./pp/launcher.nix { };
+    resultFromLauncher = l: import (builtins.readFile l);
   };
 
   # Apps for Garlic

garlic/pp/launcher.nix

@@ -0,0 +1,32 @@
+{
+  stdenv
+}:
+
+trebuchet:
+
+stdenv.mkDerivation {
+  name = "launcher";
+  preferLocalBuild = true;
+
+  phases = [ "installPhase" ];
+
+  installPhase = ''
+    if [ ! -e /garlic/run ]; then
+      echo "Missing /garlic/run, cannot continue"
+      echo "Are you running the garlicd daemon?"
+      echo
+      echo "You can manually run the experiment and fetch the results with:"
+      echo
+      echo -e "\e[30;48;5;2mgarlic -RFv ${trebuchetStage}\e[0m"
+      echo
+      echo "See garlic(1) for more details."
+      exit 1
+    fi
+
+    echo ${trebuchet} >> /garlic/run
+    echo "Waiting for experiment results..."
+    results=$(cat /garlic/completed)
+    #ln -s $results $out
+    echo -n "$results" > $out
+  '';
+}