[base-containers] add support for common run file (#805)

To keep retrocompatibility, first look in mounted ``/task``, then in RO-mounted ``/course/common``, then in ``/course``

base-containers/base/bin/INGInious

@@ -277,7 +277,7 @@ class INGIniousMainRunner:
 
         if run_cmd is not None:
             return run_cmd.split(" ")
-        for prefix in ["task", "course"]:
+        for prefix in ["task", "course/common", "course"]:
             if os.path.exists("/{}/run".format(prefix)):
                 return ["/{}/run".format(prefix)]
             for ext, cmd in run_types.items():

base-containers/base/inginious_container_api/utils.py

@@ -27,8 +27,12 @@ def set_limits_user(user):
 
 
 def set_executable(filename):
-    st = os.stat(filename)
-    os.chmod(filename, st.st_mode | stat.S_IEXEC)
+    # When mounting the course/common/run file, the permissions of the file on the host and in the container will still be the same
+    # It should therefore already be executable on the host for the moment
+    # TODO: fix this problem by moving the set_executable function to the agent where temporary folder is created for example
+    if not filename.startswith("/course/common"):
+        st = os.stat(filename)
+        os.chmod(filename, st.st_mode | stat.S_IEXEC)
 
 
 def execute_process(args, stdin_string="", internal_command=False, user="worker"):