Stubbing out dockmaster funcs/types

dockmaster.cabal

@@ -20,10 +20,14 @@ description:
 library
   hs-source-dirs:      src
   exposed-modules:     Dockmaster.Types
+                     , Dockmaster
+  other-modules:       Dockmaster.Locator
   build-depends:       base >= 4.7 && < 5
                      , yaml
                      , text
                      , unordered-containers
+                     , shelly
+                     , text
   default-language:    Haskell2010
 
 executable dockmaster-exe

src/Dockmaster.hs

@@ -0,0 +1,47 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ExtendedDefaultRules #-}
+{-# OPTIONS_GHC -fno-warn-type-defaults #-}
+module Dockmaster
+  ( dm
+  ) where
+
+-- Local modules
+import Dockmaster.Locator
+
+-- External modules
+import Shelly
+import Prelude hiding (FilePath)
+import qualified Data.Text as T
+default (T.Text)
+
+-- | Possibly provide sum type data = DcUp | DcDown | ... with to string method
+type DCCommand = T.Text
+
+-- | Runs docker-compose commands against resolved composition locations
+-- See usage docs for more info. Tries to find a dockmaster.yml file based on
+-- the initial path argument
+dm :: FilePath -> DCCommand -> [T.Text] -> Sh (T.Text)
+dm path command args = do
+  gwd <- getWorkDir path
+  case gwd of
+    Left err -> do
+                echo_n_err err
+                return err -- maybe dm should return Either and executable handles printing?
+    Right wd -> sub $ do
+      cd wd
+      dockermachine -- TODO handle Left errors
+      hookWrap command $ dockercompose $ command : args
+
+dockercompose :: [T.Text] -> Sh T.Text
+dockercompose = run "docker-compose"
+
+-- | Executes specific dc command pre/post hooks around action argument
+-- (action arg is typically docker-compose command)
+hookWrap :: DCCommand -> Sh a -> Sh a
+hookWrap = undefined
+
+-- | Reads from dockmaster.yml to find machine, attempts to connect
+-- dm should HALT when machine is unreachable
+dockermachine :: Sh (Either T.Text ())
+dockermachine = undefined
+

src/Dockmaster/Locator.hs

@@ -0,0 +1,33 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ExtendedDefaultRules #-}
+{-# OPTIONS_GHC -fno-warn-type-defaults #-}
+module Dockmaster.Locator
+  ( workDirExec
+  , getWorkDir
+  , cdWorkDir
+  ) where
+
+import Shelly
+import Prelude hiding (FilePath)
+import qualified Data.Text as T
+default (T.Text)
+
+-- | Execute action in workdir (does not affect cwd outside of action)
+workDirExec :: FilePath -> Sh a -> Sh (Either T.Text a)
+workDirExec = undefined
+
+-- | Resolve the appropriate docker-compose workdir (based on path arg)
+-- TODO This needs error handling when dockmaster.yml not found
+getWorkDir :: FilePath -> Sh (Either T.Text FilePath)
+getWorkDir p
+  -- search for dockmaster.yml
+  -- aggregate searched dirs for verbosity msg ?
+  | p /= "."  = do return $ Left "dockmaster.yml file not found"
+  | otherwise = do
+    wd <- pwd
+    return $ Right wd
+
+-- | Cd into workdir
+-- TODO check if cd retains context when run externally (i.e. do I need to pass action here)
+cdWorkDir :: FilePath -> Sh (Either T.Text (Sh ()))
+cdWorkDir = undefined