Report an error when registering an engine without setting the tracer.

Author: carlosalberto

sqlalchemy_opentracing/__init__.py

@@ -12,11 +12,13 @@ def init_tracing(tracer, trace_all_engines=False, trace_all_queries=False):
     can be passed as well.
     '''
     global g_tracer, g_trace_all_queries
+
     if hasattr(tracer, '_tracer'):
-        g_tracer = tracer._tracer
+        tracer = tracer._tracer
     else:
-        g_tracer = tracer
+        tracer = tracer
 
+    g_tracer = tracer
     g_trace_all_queries = trace_all_queries
 
     if trace_all_engines:
@@ -79,6 +81,9 @@ def register_engine(obj):
     '''
     Register an engine to have its events be traced.
     '''
+    if g_tracer is None:
+        raise RuntimeError('The tracer is not properly set')
+
     listen(obj, 'before_cursor_execute', _engine_before_cursor_handler)
     listen(obj, 'after_cursor_execute', _engine_after_cursor_handler)
     listen(obj, 'handle_error', _engine_error_handler)

tests/test_api.py

@@ -15,6 +15,9 @@ def setUp(self):
             Column('name', String),
         )
 
+    def tearDown(self):
+        sqlalchemy_opentracing.g_tracer = None
+
     def test_init(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
@@ -64,3 +67,8 @@ def test_has_parent_none(self):
         self.assertEqual(False, sqlalchemy_opentracing.has_parent_span(stmt))
         self.assertEqual(None, sqlalchemy_opentracing.get_parent_span(stmt))
 
+    def test_register_no_tracer(self):
+        engine = create_engine('sqlite:///:memory:')
+        with self.assertRaises(RuntimeError):
+            sqlalchemy_opentracing.register_engine(engine)
+

tests/test_core.py

@@ -15,13 +15,15 @@ def setUp(self):
             Column('id', Integer, primary_key=True),
             Column('name', String),
         )
-        sqlalchemy_opentracing.register_engine(self.engine)
+    def tearDown(self):
+        sqlalchemy_opentracing.g_tracer = None
 
     def test_traced(self):
         tracer = DummyTracer()
-        creat = CreateTable(self.users_table)
-
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
+        creat = CreateTable(self.users_table)
         sqlalchemy_opentracing.set_traced(creat)
         self.engine.execute(creat)
 
@@ -38,31 +40,32 @@ def test_traced(self):
 
     def test_traced_none(self):
         tracer = DummyTracer()
-        creat = CreateTable(self.users_table)
-
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
+        creat = CreateTable(self.users_table)
         self.engine.execute(creat)
 
         self.assertEqual(0, len(tracer.spans))
 
     def test_traced_all_queries(self):
         tracer = DummyTracer()
-        creat = CreateTable(self.users_table)
-
         sqlalchemy_opentracing.init_tracing(tracer, trace_all_queries=True)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
+        creat = CreateTable(self.users_table)
         self.engine.execute(creat)
 
         self.assertEqual(1, len(tracer.spans))
 
     def test_traced_all_engines(self):
-        # Create an engine that is not registered.
-        e = create_engine('sqlite:///:memory:')
+        # Don't register the engine explicitly.
         tracer = DummyTracer()
-        creat = CreateTable(self.users_table)
-
         sqlalchemy_opentracing.init_tracing(tracer, trace_all_engines=True)
+
+        creat = CreateTable(self.users_table)
         sqlalchemy_opentracing.set_traced(creat)
-        e.execute(creat)
+        self.engine.execute(creat)
 
         # Unregister the main Engine class before doing our assertions,
         # in case we fail.
@@ -74,9 +77,10 @@ def test_traced_all_engines(self):
 
     def test_traced_error(self):
         tracer = DummyTracer()
-        creat = CreateTable(self.users_table)
-
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
+        creat = CreateTable(self.users_table)
         self.engine.execute(creat)
         self.assertEqual(0, len(tracer.spans))
 
@@ -100,8 +104,9 @@ def test_traced_error(self):
 
     def test_trace_text(self):
         tracer = DummyTracer()
-
         sqlalchemy_opentracing.init_tracing(tracer, trace_all_queries=True)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
         self.engine.execute('CREATE TABLE users (id INTEGER NOT NULL, name VARCHAR, PRIMARY KEY (id))')
         self.assertEqual(1, len(tracer.spans))
         self.assertEqual(tracer.spans[0].operation_name, 'textclause')
@@ -115,8 +120,9 @@ def test_trace_text(self):
 
     def test_trace_text_error(self):
         tracer = DummyTracer()
-
         sqlalchemy_opentracing.init_tracing(tracer, trace_all_queries=True)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
         try:
             self.engine.execute('SELECT name FROM users')
         except OperationalError:
@@ -136,11 +142,13 @@ def test_trace_text_error(self):
 
     def test_traced_transaction(self):
         tracer = DummyTracer()
+        sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
         creat = CreateTable(self.users_table)
         ins = self.users_table.insert().values(name='John Doe')
         sel = select([self.users_table])
 
-        sqlalchemy_opentracing.init_tracing(tracer)
         parent_span = DummySpan('parent span')
         conn = self.engine.connect()
         with conn.begin() as trans:
@@ -157,11 +165,13 @@ def test_traced_transaction(self):
 
     def test_traced_transaction_nested(self):
         tracer = DummyTracer()
+        sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
         creat = CreateTable(self.users_table)
         ins = self.users_table.insert().values(name='John Doe')
         sel = select([self.users_table])
 
-        sqlalchemy_opentracing.init_tracing(tracer)
         parent_span = DummySpan('parent span')
         conn = self.engine.connect()
 
@@ -181,13 +191,15 @@ def test_traced_transaction_nested(self):
 
     def test_traced_rollback(self):
         tracer = DummyTracer()
+        sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
         creat = CreateTable(self.users_table)
         ins = self.users_table.insert().values(name='John Doe')
 
         # Don't trace this.
         self.engine.execute(creat)
 
-        sqlalchemy_opentracing.init_tracing(tracer)
         parent_span = DummySpan('parent span')
         conn = self.engine.connect()
         try:
@@ -208,9 +220,11 @@ def test_traced_rollback(self):
 
     def test_traced_after_transaction(self):
         tracer = DummyTracer()
+        sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
         creat = CreateTable(self.users_table)
 
-        sqlalchemy_opentracing.init_tracing(tracer)
         conn = self.engine.connect()
         with conn.begin() as tx:
             sqlalchemy_opentracing.set_traced(conn)
@@ -229,10 +243,12 @@ def test_traced_after_transaction(self):
 
     def test_traced_after_rollback(self):
         tracer = DummyTracer()
+        sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
         creat = CreateTable(self.users_table)
 
         # Create a table, but don't trace it
-        sqlalchemy_opentracing.init_tracing(tracer)
         conn = self.engine.connect()
         with conn.begin() as tx:
             conn.execute(creat)
@@ -257,11 +273,12 @@ def test_traced_after_rollback(self):
 
     def test_traced_clear_connection(self):
         tracer = DummyTracer()
+        sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
         creat = CreateTable(self.users_table)
         ins = self.users_table.insert().values(name='John Doe')
 
-        sqlalchemy_opentracing.init_tracing(tracer)
-
         conn = self.engine.connect()
         with conn.begin() as tx:
             sqlalchemy_opentracing.set_traced(conn)
@@ -277,9 +294,10 @@ def test_traced_clear_connection(self):
 
     def test_unregister_engine(self):
         tracer = DummyTracer()
-        creat = CreateTable(self.users_table)
-
         sqlalchemy_opentracing.init_tracing(tracer, trace_all_queries=True)
+        sqlalchemy_opentracing.register_engine(self.engine)
+
+        creat = CreateTable(self.users_table)
         self.engine.execute(creat)
         self.assertEqual(1, len(tracer.spans))
 

tests/test_orm.py

@@ -21,11 +21,13 @@ def setUp(self):
         self.session = sessionmaker(bind=self.engine)()
         User.metadata.create_all(self.engine)
 
-        sqlalchemy_opentracing.register_engine(self.engine)
+    def tearDown(self):
+        sqlalchemy_opentracing.g_tracer = None
 
     def test_traced_simple(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         sqlalchemy_opentracing.set_traced(session)
@@ -45,6 +47,7 @@ def test_traced_simple(self):
     def test_traced_none(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         session.add(User(name='John Doe'))
@@ -57,6 +60,7 @@ def test_traced_none(self):
     def test_traced_all(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer, trace_all_queries=True)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         session.add(User(name='John Doe'))
@@ -71,6 +75,7 @@ def test_traced_all(self):
     def test_traced_error(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         # Don't trace this one.
         session = self.session
@@ -100,6 +105,7 @@ def test_traced_error(self):
     def test_traced_parent(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         parent_span = DummySpan('parent')
@@ -116,6 +122,7 @@ def test_traced_parent(self):
     def test_traced_text(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         span = DummySpan('parent span')
@@ -136,6 +143,7 @@ def test_traced_text(self):
     def test_traced_text_error(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         span = DummySpan('parent span')
@@ -161,6 +169,7 @@ def test_traced_text_error(self):
     def test_traced_after_commit(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         sqlalchemy_opentracing.set_traced(session)
@@ -181,6 +190,7 @@ def test_traced_after_commit(self):
     def test_traced_after_rollback(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         sqlalchemy_opentracing.set_traced(session)
@@ -203,6 +213,7 @@ def test_traced_after_rollback(self):
     def test_traced_commit_repeat(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         parent_span1 = DummySpan('parent1')
         session = self.session
@@ -227,6 +238,7 @@ def test_traced_commit_repeat(self):
     def test_traced_savepoint(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         sqlalchemy_opentracing.set_traced(session)
@@ -245,6 +257,7 @@ def test_traced_savepoint(self):
     def test_traced_bulk_insert(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         parent_span = DummySpan('parent')
         session = self.session
@@ -265,6 +278,7 @@ def test_traced_bulk_insert(self):
     def test_traced_clear_session(self):
         tracer = DummyTracer()
         sqlalchemy_opentracing.init_tracing(tracer)
+        sqlalchemy_opentracing.register_engine(self.engine)
 
         session = self.session
         sqlalchemy_opentracing.set_traced(session)