job/task: Check if allowed to override or fail

Signed-off-by: Alexander Jung <a.jung@lancs.ac.uk>

job/task.go

@@ -61,8 +61,19 @@ func (t *Task) Init(workDir string, allowOverride bool, runs *[]Run) error {
   // Create a queue of runs for this particular task
   t.runs = NewQueue(len(*runs))
 
-  // Create a working directory for this task
+  // Set the working directory
   t.workDir = path.Join(workDir, "results", t.UUID())
+
+  // Check if we're allowed to override a non-empty directory
+  isEmpty, err := IsDirEmpty(t.workDir)
+  if err != nil {
+    return err
+  }
+  if !isEmpty && !allowOverride {
+    return fmt.Errorf("Task directory not empty: %s", t.workDir)
+  }
+
+  // Create a working directory for this task
   if _, err := os.Stat(t.workDir); os.IsNotExist(err) {
     os.MkdirAll(workDir, os.ModePerm)
   }