Avoid to handle a late init message

Signed-off-by: Chenxiong Qi <cqi@redhat.com>

module_build_service/scheduler/handlers/modules.py

@@ -153,6 +153,16 @@ def init(msg_id, module_build_id, module_build_state):
     """
     build = models.ModuleBuild.get_by_id(db_session, module_build_id)
 
+    state_init = models.BUILD_STATES["init"]
+    if module_build_state == state_init and build.state != state_init:
+        log.warning(
+            "Module build %r has moved to %s state already.",
+            build, models.INVERSE_BUILD_STATES[build.state])
+        log.warning(
+            "Ignore this message %s. Is there something wrong with the frontend"
+            " that sends duplicate messages?", msg_id)
+        return
+
     # for MockModuleBuilder, set build logs dir to mock results dir
     # before build_logs start
     if conf.system == "mock":

tests/test_scheduler/test_module_init.py

@@ -6,7 +6,7 @@ import os
 from mock import patch, PropertyMock
 
 from module_build_service import build_logs, conf
-from module_build_service.common.models import ModuleBuild
+from module_build_service.common.models import BUILD_STATES, ModuleBuild
 from module_build_service.common.utils import load_mmd, mmd_to_str
 from module_build_service.scheduler.db_session import db_session
 import module_build_service.scheduler.handlers.modules
@@ -180,3 +180,13 @@ class TestModuleInit:
         # Make sure the module entered the failed state
         assert build.state == 4, build.state
         assert "Failed to get the latest commit for" in build.state_reason
+
+    def test_do_not_handle_a_duplicate_late_init_message(self):
+        build = db_session.query(ModuleBuild).filter(
+            ModuleBuild.name == "testmodule").one()
+        build.state = BUILD_STATES["wait"]
+        db_session.commit()
+
+        with patch.object(module_build_service.scheduler.handlers.modules, "log") as log:
+            self.fn("msg-id-123", build.id, BUILD_STATES["init"])
+            assert 2 == log.warning.call_count