added check for /tmp or /var/tmp (#885)

Add check to make sure workdir isn't /var or /var/tmp

beeflow/client/bee_client.py

@@ -260,6 +260,12 @@ def is_parent(parent, path):
     if not os.path.exists(workdir):
         error_exit(f"Workflow working directory \"{workdir}\" doesn't exist")
 
+    # Make sure the workdir is not in /var or /var/tmp
+    if os.path.commonpath([os.path.realpath('/tmp'), workdir]) == os.path.realpath('/tmp'):
+        error_exit("Workflow working directory cannot be in \"/tmp\"")
+    if os.path.commonpath([os.path.realpath('/var/tmp'), workdir]) == os.path.realpath('/var/tmp'):
+        error_exit("Workflow working directory cannot be in \"/var/tmp\"")
+
     # TODO: Can all of this information be sent as a file?
     data = {
         'wf_name': wf_name.encode(),