Make test-prepare-workspace-git role

This is a copy of prepare-workspace-git except that it imports
test-mirror-workspace-git-repos.  This is for base job testing.

Change-Id: I4ef3e4376c9e958761c165836c4fb546157e237a

doc/source/deprecated-roles.rst

@@ -4,3 +4,4 @@ Deprecated and Test Roles
 .. zuul:autorole:: fetch-zuul-cloner
 .. zuul:autorole:: test-mirror-workspace-git-repos
 .. zuul:autorole:: test-upload-logs-swift
+.. zuul:autorole:: test-prepare-workspace-git

roles/test-prepare-workspace-git/README.rst

@@ -0,0 +1,17 @@
+Mirror the local git repos to remote nodes
+
+This role uses git operations (unlike :zuul:role:`prepare-workspace`
+which uses rsync) to mirror the locally prepared git repos to the remote
+nodes while taking advantage of cached repos on the node if they exist.
+This role works generically regardless of the existence of a cached
+repo on the node.
+
+The cached repos need to be placed using the canonical name under the
+`cached_repos_root` directory.
+
+**Role Variables**
+
+.. zuul:rolevar:: cached_repos_root
+   :default: /opt/git
+
+   The root of the cached repos.

roles/test-prepare-workspace-git/defaults/main.yaml

@@ -0,0 +1 @@
+cached_repos_root: /opt/git

roles/test-prepare-workspace-git/tasks/main.yaml

@@ -0,0 +1,64 @@
+- name: Find locally cached git repos
+  stat:
+    path: "{{ cached_repos_root }}/{{ zj_project.canonical_name }}"
+  with_items: "{{ zuul.projects.values() | list }}"
+  loop_control:
+    loop_var: zj_project
+  register: cached_repos
+
+# We do a bare clone here first so that we skip creating a working copy that
+# will be overwritten later anyway.
+- name: Clone cached repo to workspace
+  shell: |
+    set -e
+    git clone --bare {{ cached_repos_root }}/{{ zj_project.0.canonical_name }} {{ ansible_user_dir }}/{{ zj_project.0.src_dir }}/.git
+    cd {{ ansible_user_dir }}/{{ zj_project.0.src_dir }}
+    git config --local --bool core.bare false
+  args:
+    creates: "{{ ansible_user_dir }}/{{ zj_project.0.src_dir }}"
+  when: zj_project.1.stat.exists
+  with_together:
+    - "{{ zuul.projects.values() | list }}"
+    - "{{ cached_repos.results }}"
+  loop_control:
+    loop_var: zj_project
+  # ANSIBLE0006: If we use the git module, we get warning
+  # ANSIBLE0004 since we  do not give an explicit version
+  tags:
+    - skip_ansible_lint
+
+- name: Initialize non-cached repos
+  command: "git init {{ ansible_user_dir }}/{{ zj_project.0.src_dir }}"
+  args:
+    creates: "{{ ansible_user_dir }}/{{ zj_project.0.src_dir }}"
+  when: not zj_project.1.stat.exists
+  with_together:
+    - "{{ zuul.projects.values() | list }}"
+    - "{{ cached_repos.results }}"
+  loop_control:
+    loop_var: zj_project
+  # ANSIBLE0006: If we use the git module, we get warning
+  # ANSIBLE0004 since we  do not give an explicit version
+  tags:
+    - skip_ansible_lint
+
+- name: Remove origin from local git repos and replace it by the zuul fake origin
+  # To be idempotent, remove origin only if it's found in the local list.
+  shell: |
+    set -e
+    git remote -v | grep origin && git remote rm origin || true
+    git remote add origin file:///dev/null
+  args:
+    chdir: "{{ ansible_user_dir }}/{{ zj_project.src_dir }}"
+  with_items: "{{ zuul.projects.values() | list }}"
+  loop_control:
+    loop_var: zj_project
+  # ANSIBLE0006: git remote is not supported by ansible module
+  tags:
+    - skip_ansible_lint
+
+# TODO(tobiash): we might want to deprecate the role mirror-workspace-git-repos
+# and move it here.
+- name: Synchronize repos
+  import_role:
+    name: test-mirror-workspace-git-repos