Allow zuul pre playbook bootstrap to be skipped

This is needed if a child job in an openstack-ansible role repo
needs to do some configuration before bootstrap-ansible is run.

An example might be configuring extra roles, collections or
pythin modules to be installed during bootstrap.

Change-Id: I463cf5df7c2aa4e2cdf399efaeb17df980d29edc

zuul.d/playbooks/pre-osa-aio.yml

@@ -40,7 +40,9 @@
         ZUUL_SRC_PATH: "{{ (action != 'shastest') | ternary(_zuul_src_path, '') }}"
         ANSIBLE_PACKAGE: "{{ ansible_package | default('') }}"
         SETUP_ARA: 'true'
-      when: "'upgrade' not in action"
+      when:
+        - "'upgrade' not in action"
+        - osa_pre_run_bootstrap | default(True)
     - name: Run bootstrap-aio script
       become: yes
       become_user: root
@@ -59,3 +61,4 @@
         - "'upgrade' not in action"
         - action != 'linters'
         - action != 'shastest'
+        - osa_pre_run_bootstrap | default(True)

zuul.d/playbooks/run.yml

@@ -13,12 +13,19 @@
       args:
         chdir: "src/opendev.org/openstack/openstack-ansible"
         executable: /bin/bash
-      environment:
+      vars:
+        skip_bootstrap:
           # NOTE(logan): ARA is already installed in the gate environment by the
           # pre-osa-aio pre-run playbook
-        SETUP_ARA: false
+          SETUP_ARA: False
           # NOTE(logan): The project is bootstrapped in the pre playbook so the
           # bootstrapping can be skipped here
           SKIP_OSA_RUNTIME_VENV_BUILD: 1
           SKIP_OSA_BOOTSTRAP_AIO: 1
           SKIP_OSA_ROLE_CLONE: 1
+        run_bootstrap:
+          # NOTE(jrosser)
+          # ZUUL_SRC_PATH is needed for bootstrap-ansible inside gate-check-commit.sh
+          # when pre playbook bootstrap is disabled
+          ZUUL_SRC_PATH: "{{ ansible_user_dir }}/src"
+      environment: "{{ (osa_pre_run_bootstrap | default(True)) | ternary(skip_bootstrap, run_bootstrap) }}"