Use a venv with previous ansible version for upgrades

When doing the role upgrade, we run every playbook with current's
branch ansible. This is normal for the infrastructure bits (which
are running on current branch), but not for the installation of
the previous branch's role, which should use previous branch's
environment.

Related-Bug: #1741471
Depends-On: I7ebb045885dd645b820de2b7f75b46c755c015f6
Change-Id: I7bc4dd644c48b403e9e669cb0ea460d9d1149410

tests/test-galera-upgrades.sh

@@ -49,7 +49,8 @@ echo "TEST_IDEMPOTENCE: ${TEST_IDEMPOTENCE}"
 function execute_ansible_playbook {
 
   export ANSIBLE_CLI_PARAMETERS="${ANSIBLE_PARAMETERS} -e @${ANSIBLE_OVERRIDES}"
-  CMD_TO_EXECUTE="ansible-playbook ${TEST_PLAYBOOK} $@ ${ANSIBLE_CLI_PARAMETERS}"
+  export ANSIBLE_BIN=${ANSIBLE_BIN:-"ansible-playbook"}
+  CMD_TO_EXECUTE="${ANSIBLE_BIN} ${TEST_PLAYBOOK} $@ ${ANSIBLE_CLI_PARAMETERS}"
 
   echo "Executing: ${CMD_TO_EXECUTE}"
   echo "With:"
@@ -72,7 +73,7 @@ source "${COMMON_TESTS_PATH}/test-ansible-env-prep.sh"
 # Set gate job exit traps, this is run regardless of exit state when the job finishes.
 trap gate_job_exit_tasks EXIT
 
-# Prepare environment for the initial deploy of previous version
+# Prepare environment for the initial deploy of (previous and current) Galera
 # No upgrading or testing is done yet.
 export TEST_PLAYBOOK="${WORKING_DIR}/tests/test-upgrade-pre.yml"
 export ANSIBLE_LOG_PATH="${ANSIBLE_LOG_DIR}/ansible-execute-install.log"
@@ -80,6 +81,22 @@ export ANSIBLE_LOG_PATH="${ANSIBLE_LOG_DIR}/ansible-execute-install.log"
 # Execute the setup of previous version
 execute_ansible_playbook
 
+# Create an ansible venv matching previous branch
+source ${WORKING_DIR}/tests/common/test-create-previous-venv.sh
+
+# Prepare environment for the deploy of previous Galera:
+# No upgrading or testing is done yet.
+export TEST_PLAYBOOK="${WORKING_DIR}/tests/test-install-previous-galera.yml"
+export ANSIBLE_LOG_PATH="${ANSIBLE_LOG_DIR}/ansible-execute-previous_galera-install.log"
+export PREVIOUS_VENV="ansible-previous"
+export ANSIBLE_BIN="${WORKING_DIR}/.tox/${PREVIOUS_VENV}/bin/ansible-playbook"
+
+# Execute the setup of previous Keystone
+execute_ansible_playbook
+# Unset previous branch overrides
+unset PREVIOUS_VENV
+unset ANSIBLE_BIN
+
 # Prepare environment for the upgrade
 export TEST_PLAYBOOK="${WORKING_DIR}/tests/test-upgrade-post.yml"
 export ANSIBLE_LOG_PATH="${ANSIBLE_LOG_DIR}/ansible-execute-upgrade.log"

tests/test-install-previous-galera.yml

@@ -0,0 +1,25 @@
+---
+# Copyright 2018, SUSE LINUX GmbH.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Install previous version
+- name: Deploy previous galera version
+  hosts: galera_all
+  user: root
+  serial: 1
+  gather_facts: true
+  roles:
+    - role: "previous_galera_server"
+  vars_files:
+    - common/previous/test-vars.yml

tests/test-upgrade-pre.yml

@@ -18,14 +18,3 @@
 
 # Prepare the containers
 - include: common/test-prepare-containers.yml
-
-# Install previous version
-- name: Deploy previous galera version
-  hosts: galera_all
-  user: root
-  serial: 1
-  gather_facts: true
-  roles:
-    - role: "previous_galera_server"
-  vars_files:
-    - common/previous/test-vars.yml