Add migration tool for v2 to v3 conversion

We need to be able to generate a new v3 config based on our old v2
config. It won't be perfect, but should ultimately be no worse than the
v2.5 auto-generated playbooks.

Change-Id: I9cb676ceff01bbdb845d22774edbaa718323db27
diff --git a/playbooks/zuul-migrate.yaml b/playbooks/zuul-migrate.yaml
new file mode 100644
index 0000000..66c7bd5
--- /dev/null
+++ b/playbooks/zuul-migrate.yaml
@@ -0,0 +1,18 @@
+- hosts: all
+  tasks:
+
+    - name: Install migration dependencies
+      command: "python3 -m pip install --user src/git.openstack.org/openstack-infra/zuul[migrate]"
+
+    - name: Migrate the data
+      command: "python3 ../zuul/zuul/cmd/migrate.py zuul/layout.yaml jenkins/jobs nodepool/nodepool.yaml . --mapping=zuul/mapping.yaml -v -m"
+      args:
+        chdir: src/git.openstack.org/openstack-infra/project-config
+
+    - name: Collect generated files
+      synchronize:
+        dest: "{{ zuul.executor.log_root }}"
+        mode: pull
+        src: "src/git.openstack.org/openstack-infra/project-config/zuul.d"
+        verify_host: true
+      no_log: true