Run tests on PostgreSQL and MySQL too

In addition to running tests with different Python and SQLAlchemy
versions, they should also be run on different DB backends, which
are used in production (PostgreSQL and MySQL).

This patch:
  - modifies test_db.cfg to run tests on PostgreSQL and MySQL
    (Jenkins Slave credentials are used here, to ensure these
    tests are always run by Jenkins gate); if a backend is not
    available, test cases will be skipped for it
  - concurrency is set to 1 (sharing of the one MySQL or PostgreSQL
    DB among different test runner processes would lead to
    race conditions)
  - fixes tests dropping FK columns in MySQL: in earlier MySQL
    versions dropping a column that is a part of a FK constraint
    would lead to dropping of the FK too. As of MySQL 5.5 that's
    not the case anymore: if one tries to drop such column, he/she
    will get a very obscure error (something like "Error on rename
    of './openstack_citest/#sql-4af_aa2' to './openstack_citest/tmp_adddropcol'
    (errno: 150)") '\nALTER TABLE tmp_adddropcol DROP COLUMN r2').
    So the solution if to drop FK constraints first, and only then
    the columns it is made up of

Change-Id: I8c5d2874c83e7df46da69969ed54d85437c849e7

migrate/tests/changeset/test_changeset.py

@@ -7,6 +7,7 @@ from sqlalchemy import *
 
 from migrate import changeset, exceptions
 from migrate.changeset import *
+from migrate.changeset import constraint
 from migrate.changeset.schema import ColumnDelta
 from migrate.tests import fixture
 from migrate.tests.fixture.warnings import catch_warnings
@@ -168,7 +169,7 @@ class TestAddDropColumn(fixture.DB):
         reftable.create()
 
         # create column with fk
-        col = Column('data', Integer, ForeignKey(reftable.c.id))
+        col = Column('data', Integer, ForeignKey(reftable.c.id, name='testfk'))
         col.create(self.table)
 
         # check if constraint is added
@@ -186,6 +187,11 @@ class TestAddDropColumn(fixture.DB):
         else:
             self.assertEqual(reftable.c.id.name,
                 col.foreign_keys[0].column.name)
+
+        if self.engine.name == 'mysql':
+            constraint.ForeignKeyConstraint([self.table.c.data],
+                                            [reftable.c.id],
+                                            name='testfk').drop()
         col.drop(self.table)
 
         if self.engine.has_table(reftable.name):
@@ -384,8 +390,8 @@ class TestAddDropColumn(fixture.DB):
         self.table = Table(
             self.table_name, self.meta,
             Column('id', Integer, primary_key=True),
-            Column('r1', Integer, ForeignKey('tmp_ref.id')),
-            Column('r2', Integer, ForeignKey('tmp_ref.id')),
+            Column('r1', Integer, ForeignKey('tmp_ref.id', name='test_fk1')),
+            Column('r2', Integer, ForeignKey('tmp_ref.id', name='test_fk2')),
             )
         self.table.create()
 
@@ -394,6 +400,9 @@ class TestAddDropColumn(fixture.DB):
                          self._actual_foreign_keys())
         
         # delete one
+        if self.engine.name == 'mysql':
+            constraint.ForeignKeyConstraint([self.table.c.r2], [reftable.c.id],
+                                            name='test_fk2').drop()
         self.table.c.r2.drop()
         
         # check remaining foreign key is there
@@ -435,6 +444,10 @@ class TestAddDropColumn(fixture.DB):
                          self._actual_foreign_keys())
         
         # delete one
+        if self.engine.name == 'mysql':
+            constraint.ForeignKeyConstraint([self.table.c.r1, self.table.c.r2],
+                                            [reftable.c.id, reftable.c.jd],
+                                            name='test_fk').drop()
         self.table.c.r2.drop()
         
         # check the constraint is gone, since part of it

migrate/tests/fixture/database.py

@@ -6,6 +6,7 @@ import logging
 from decorator import decorator
 
 from sqlalchemy import create_engine, Table, MetaData
+from sqlalchemy import exc as sa_exc
 from sqlalchemy.orm import create_session
 from sqlalchemy.pool import StaticPool
 
@@ -81,13 +82,17 @@ def usedb(supported=None, not_supported=None):
             try:
                 log.debug("Running test with engine %s", url)
                 try:
-                    try:
-                        self._setup(url)
-                    except Exception,e:
-                        setup_exception=e
-                    else:
-                        setup_exception=None
-                        f(self, *a, **kw)
+                    self._setup(url)
+                except sa_exc.OperationalError:
+                    log.info('Backend %s is not available, skip it', url)
+                    continue
+                except Exception as e:
+                    setup_exception = e
+                else:
+                    setup_exception = None
+
+                try:
+                    f(self, *a, **kw)
                 finally:
                     try:
                         self._teardown()

test_db.cfg

@@ -8,7 +8,7 @@
 # The string '__tmp__' is substituted for a temporary file in each connection
 # string. This is useful for sqlite tests.
 sqlite:///__tmp__
-#postgresql://postgres@localhost/testdb
-#mysql://root@localhost/testdb
+postgresql://openstack_citest:openstack_citest@localhost/openstack_citest
+mysql://openstack_citest:openstack_citest@localhost/openstack_citest
 #oracle://scott:tiger@localhost
 #firebird://scott:tiger@localhost//var/lib/firebird/databases/test_migrate

tox.ini

@@ -10,7 +10,7 @@ setenv = VIRTUAL_ENV={envdir}
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands =
-  python setup.py testr --slowest --testr-args='{posargs}'
+  python setup.py testr --slowest --testr-args='{posargs} --concurrency=1'
 
 [testenv:py26sa07]
 basepython = python2.6