Zuul v3: add role to set up base dir

Change-Id: I825b6fda85997d59dc136280f03e7497eb7b3c2e

playbooks/pre.yaml

@@ -1,3 +1,5 @@
 - hosts: all
   roles:
     - write-devstack-local-conf
+    - setup-devstack-source-dirs
+

roles/setup-devstack-source-dirs/README.rst

@@ -0,0 +1,11 @@
+Set up the devstack source directories
+
+Ensure that the base directory exists, and then move the source repos
+into it.
+
+**Role Variables**
+
+.. zuul:rolevar:: devstack_base_dir
+   :default: /opt/stack
+
+   The devstack base directory.

roles/setup-devstack-source-dirs/defaults/main.yaml

@@ -0,0 +1 @@
+devstack_base_dir: /opt/stack

roles/setup-devstack-source-dirs/tasks/main.yaml

@@ -0,0 +1,17 @@
+- name: Create base directory
+  file: path={{ devstack_base_dir }} state=directory
+  become: yes
+
+- name: Find all source repos used by this job
+  find:
+    paths:
+      - src/git.openstack.org/openstack
+      - src/git.openstack.org/openstack-dev
+      - src/git.openstack.org/openstack-infra
+    file_type: directory
+  register: found_repos
+
+- name: Move Zuul repos into place
+  command: mv {{ item.path }} {{ devstack_base_dir }}
+  with_items: '{{ found_repos.files }}'
+  become: yes