ogma-cli: Provide CLI argument to pass an auxiliary template source d…

…irectory to cFS app command. Refs nasa#157.

The cFS application generation backend has a fixed template that it uses
to generate the cFS application. That template does not fit all use
cases, so we are finding users heavily modifying the output (which is
hard to keep up with when there are changes), and or not using ogma
altogether for that reason.

A recent commit introduced into ogma-core the ability to use a custom
provided template and expand variables using mustache.

This commit exposes that new parameter to the user in the CLI.

ogma-cli/src/CLI/CommandCFSApp.hs

@@ -56,9 +56,10 @@ import Command.CFSApp ( ErrorCode, cFSApp )
 
 -- | Options needed to generate the cFS application.
 data CommandOpts = CommandOpts
-  { cFSAppTarget   :: String
-  , cFSAppVarNames :: String
-  , cFSAppVarDB    :: Maybe String
+  { cFSAppTarget      :: String
+  , cFSAppTemplateDir :: Maybe String
+  , cFSAppVarNames    :: String
+  , cFSAppVarDB       :: Maybe String
   }
 
 -- | Create <https://cfs.gsfc.nasa.gov/ NASA core Flight System> (cFS)
@@ -68,7 +69,11 @@ data CommandOpts = CommandOpts
 -- This is just an uncurried version of "Command.CFSApp".
 command :: CommandOpts -> IO (Result ErrorCode)
 command c =
-  cFSApp (cFSAppTarget c) (cFSAppVarNames c) (cFSAppVarDB c)
+  cFSApp
+    (cFSAppTarget c)
+    (cFSAppTemplateDir c)
+    (cFSAppVarNames c)
+    (cFSAppVarDB c)
 
 -- * CLI
 
@@ -87,6 +92,13 @@ commandOptsParser = CommandOpts
         <> value "copilot-cfs-demo"
         <> help strCFSAppDirArgDesc
         )
+  <*> optional
+        ( strOption
+            (  long "app-template-dir"
+            <> metavar "DIR"
+            <> help strCFSAppTemplateDirArgDesc
+            )
+        )
   <*> strOption
         (  long "variable-file"
         <> metavar "FILENAME"
@@ -106,6 +118,11 @@ commandOptsParser = CommandOpts
 strCFSAppDirArgDesc :: String
 strCFSAppDirArgDesc = "Target directory"
 
+-- | Argument template directory to cFS app generation command
+strCFSAppTemplateDirArgDesc :: String
+strCFSAppTemplateDirArgDesc =
+  "Directory holding cFS application source template"
+
 -- | Argument variable list to cFS app generation command
 strCFSAppVarListArgDesc :: String
 strCFSAppVarListArgDesc =