Use ZUUL_SRC_PATH to pass the path to Zuul git sources

To make get-ansible-role-requirements usable for 3rd party Zuul based
CI, which may have test nodes that do not conform to the previously
hard-coded /home/zuul home path for Zuul workers, we need to make
this Zuul sources path dynamic based on the home directory of the
Zuul worker user.

However, we cannot rely on {{ ansible_user_dir }} inside
get-ansible-role-requirements.yml, since it uses become: yes. This
means ansible_user_dir will be /root, rather than the Zuul user's
home directory.

The solution is to pass the ZUUL_SRC_PATH that Zuul is operating
with into the OSA test job environment, and use this environment var
inside our role cloning playbook to locate the Zuul sources.

Change-Id: Id71c6502741285e7b83d40be8006e82c9960b7ff
(cherry picked from commit 47eddb946b)

tests/get-ansible-role-requirements.yml

@@ -36,16 +36,22 @@
 
     - name: Use Zuul provided sources in Zuul environment
       block:
+        - name: Set Zuul sources path
+          set_fact:
+            zuul_src_path: "{{ lookup('env', 'ZUUL_SRC_PATH') }}"
         - name: Check the Zuul src dir for cloned roles
           stat:
-            path: "/home/zuul/src/{{ item.src.split('/')[-3:] | join('/') }}"
+            path: "{{ zuul_src_path }}/{{ item.src.split('/')[-3:] | join('/') }}"
+            get_attributes: no
+            get_checksum: no
+            get_mime: no
           register: zuul_roles
           when:
             - item.scm == "git" or item.scm is undefined
           with_items: "{{ required_roles }}"
         - name: Link the Zuul provided roles
           file:
-            src: "/home/zuul/src/{{ item.item.src.split('/')[-3:] | join('/') }}"
+            src: "{{ zuul_src_path }}/{{ item.item.src.split('/')[-3:] | join('/') }}"
             dest: "{{ item.item.path | default(role_path_default) }}/{{ item.item.name | default(item.item.src | basename) }}"
             state: link
             owner: root
@@ -54,7 +60,7 @@
                           | selectattr('stat.exists')
                           | list }}"
       when:
-        - "lookup('env', 'ZUUL_PROJECT') != ''"
+        - "lookup('env', 'ZUUL_SRC_PATH') != ''"
 
     - name: Clone git repos (with git)
       git:

zuul.d/playbooks/run.yml

@@ -1,5 +1,9 @@
 - hosts: all
   tasks:
+    - name: Set the Zuul sources path
+      set_fact:
+        zuul_src_path: "{{ ansible_user_dir }}/src"
+
     - name: Set current test repo (cross-repo)
       set_fact:
         current_test_repo: "git.openstack.org/{{ osa_test_repo }}"
@@ -19,7 +23,7 @@
       args:
         chdir: "src/{{ current_test_repo }}"
       environment:
-        # ZUUL_PROJECT is used by tests/get-ansible-role-requirements to
-        # determine when CI provided repos should be used.
-        ZUUL_PROJECT: "{{ zuul.project.short_name }}"
+        # ZUUL_SRC_PATH is used by tests/get-ansible-role-requirements to
+        # where the CI provided git sources were cloned.
+        ZUUL_SRC_PATH: "{{ zuul_src_path }}"
         ANSIBLE_PACKAGE: "{{ ansible_package | default('') }}"