Add option to use in-container pg_dump in tests

The pg_dump command is picky about client/server versions, so to
make it easier for developers to run tests locally using the pgsql
container, provida an option to use pg_dump from the container
instead of whatever version is installed locally, which may not
match.

Change-Id: I9add7af40b8f8d92a88d983eacbc59a01f0e7b9f

tests/unit/test_database.py

@@ -12,6 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import os
 import re
 import subprocess
 
@@ -226,8 +227,9 @@ class TestPostgresqlDatabase(DBBaseTestCase):
     def test_migration(self):
         # Test that SQLAlchemy create_all produces the same output as
         # a full migration run.
+        pg_dump = os.environ.get("ZUUL_TEST_PG_DUMP", "pg_dump")
         sqlalchemy_out = subprocess.check_output(
-            f"pg_dump -h {self.db.host} -U {self.db.name} -s {self.db.name}",
+            f"{pg_dump} -h {self.db.host} -U {self.db.name} -s {self.db.name}",
             shell=True,
             env={'PGPASSWORD': self.db.passwd}
         )
@@ -246,7 +248,7 @@ class TestPostgresqlDatabase(DBBaseTestCase):
         self.connection.onLoad(self.zk_client)
 
         alembic_out = subprocess.check_output(
-            f"pg_dump -h {self.db.host} -U {self.db.name} -s {self.db.name}",
+            f"{pg_dump} -h {self.db.host} -U {self.db.name} -s {self.db.name}",
             shell=True,
             env={'PGPASSWORD': self.db.passwd}
         )

tools/test-setup-docker.sh

@@ -62,4 +62,8 @@ ${ROOTCMD} ${MYSQL} -e "CREATE USER 'openstack_citest'@'%' identified by 'openst
 ${ROOTCMD} ${MYSQL} -e "GRANT ALL PRIVILEGES ON *.* TO 'openstack_citest'@'%' WITH GRANT OPTION;"
 ${ROOTCMD} ${MYSQL} -u openstack_citest -popenstack_citest -e "SET default_storage_engine=MYISAM; DROP DATABASE IF EXISTS openstack_citest; CREATE DATABASE openstack_citest CHARACTER SET utf8;"
 
+set +x
 echo "Finished"
+
+echo "Set this variable to use the in-container pg_dump command:"
+echo 'export ZUUL_TEST_PG_DUMP="docker exec -t zuul-test-postgres pg_dump"'