Define install_method default when hosts resolution depend on it

In some playbooks we try to fetch openstack_service_setup_host based on
install_method variable. However, if variable is not defined,
and it is not by default, playbooks will run against localhost,
which will result in failure.

Closes-Bug: #2031647
Change-Id: I247ce2a808076ff55347db54327a1e4913ea3006
(cherry picked from commit f05c90103c)

.ansible-lint

@@ -7,3 +7,6 @@ warn_list:
   - unnamed-task
   - no-handler
   - var-naming
+
+extra_vars:
+  openstack_service_setup_host: utility_all

playbooks/ceph-rgw-keystone-setup.yml

@@ -17,7 +17,7 @@
   hosts: "{{ openstack_service_setup_host | default('localhost') }}"
   user: root
   vars_files:
-    - "defaults/{{ install_method }}_install.yml"
+    - "defaults/{{ install_method | default('source') }}_install.yml"
   vars:
     ansible_python_interpreter: >-
       {{ openstack_service_setup_host_python_interpreter |

playbooks/healthcheck-infrastructure.yml

@@ -99,7 +99,7 @@
   hosts: "{{ openstack_service_setup_host | default('localhost') }}"
   gather_facts: no
   vars_files:
-    - "defaults/{{ install_method }}_install.yml"
+    - "defaults/{{ install_method | default('source') }}_install.yml"
   vars:
     ansible_python_interpreter: "{{ openstack_service_setup_host_python_interpreter | default(ansible_facts['python']['executable']) }}"
   tasks:

playbooks/os-keystone-install.yml

@@ -23,7 +23,7 @@
   hosts: "{{ openstack_service_setup_host | default('localhost') }}"
   gather_facts: "{{ osa_gather_facts | default(True) }}"
   vars_files:
-    - "defaults/{{ install_method }}_install.yml"
+    - "defaults/{{ install_method | default('source') }}_install.yml"
   become: yes
   tags:
     - openrc

scripts/gate-check-commit.sh

@@ -146,7 +146,7 @@ elif [[ "${ACTION}" == "linters" ]]; then
     else
       ROLE_DIR="${OSA_CLONE_DIR}"
       ${VENV_BIN_DIR}/ansible-lint playbooks/ --exclude /etc/ansible/roles
-      ansible-playbook --syntax-check --list-tasks playbooks/setup-everything.yml
+      ansible-playbook --syntax-check --list-tasks playbooks/setup-everything.yml -e openstack_service_setup_host=utility_all
     fi
 
     # Run bashate