cmd: Don't write json status files for non-boot stages (#4478)

Don't use status_wrapper() for `cloud-init modules --mode init`.
      
Both status.json and result.json are currently written when `cloud-init
modules --mode init` is ran. This is unecessary since this is not a boot
command used by cloud-init, and as a workaround for previous bugs related to
this behavior this leaves behind unwanted keys in status.json.

This aligns cloud-init code's behavior with documented behavior.

cloudinit/cmd/main.py

@@ -727,7 +727,6 @@ def status_wrapper(name, args, data_d=None, link_d=None):
     modes = (
         "init",
         "init-local",
-        "modules-init",
         "modules-config",
         "modules-final",
     )
@@ -1059,7 +1058,10 @@ def main(sysv_args=None):
     # Setup signal handlers before running
     signal_handler.attach_handlers()
 
-    if name in ("modules", "init"):
+    # Write boot stage data to write status.json and result.json
+    # Exclude modules --mode=init, since it is not a real boot stage and
+    # should not be written into status.json
+    if "init" == name or ("modules" == name and "init" != args.mode):
         functor = status_wrapper
 
     rname = None

tests/unittests/test_cli.py

@@ -91,6 +91,14 @@ def myaction(name, args):
         cli.status_wrapper("init", myargs, data_d, link_d)
         # No errors reported in status
         status_v1 = m_json.call_args_list[1][0][1]["v1"]
+        assert status_v1.keys() == {
+            "datasource",
+            "init-local",
+            "init",
+            "modules-config",
+            "modules-final",
+            "stage",
+        }
         assert ["an error"] == status_v1["init-local"]["errors"]
         assert "SomeDatasource" == status_v1["datasource"]
         assert False is os.path.exists(