Make prepare-workspace-git fail faster.

In case of aws spot instances, the node can drop the connection anytime.
Ansible loops do not fail when the first item fails, instead they execute all items before reporting the failure.
This leads to a big overhead, if we sync repositories, when the node has dropped the connection beforehand.
Therefore i used include_tasks, which fails for the first unsuccessful item.

Change-Id: Id6079a2cda10a825384d52d47750d9c05d323e00

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

@@ -35,32 +35,11 @@
   loop_control:
     loop_var: zj_project
 
-- name: Synchronize src repos to workspace directory
-  command: |-
-    {% if ansible_connection == "kubectl" %}
-      git push {% if mirror_workspace_quiet %}--quiet{% endif %} --mirror "ext::kubectl --context {{ zuul.resources[inventory_hostname].context }} -n {{ zuul.resources[inventory_hostname].namespace }} exec -i {{ zuul.resources[inventory_hostname].pod }} -- %S {{ zuul_workspace_root }}/{{ zj_project.value.src_dir }}"
-    {% else %}
-      git push {% if mirror_workspace_quiet %}--quiet{% endif %} --mirror git+ssh://{{ ansible_user }}@{{ ansible_host | ipwrap }}:{{ ansible_port }}/{{ zuul_workspace_root }}/{{ zj_project.value.src_dir }}
-    {% endif %}
-  args:
-    chdir: "{{ zuul.executor.work_root }}/{{ zj_project.value.src_dir }}"
-  environment:
-    GIT_ALLOW_PROTOCOL: ext:ssh
+- name: Include tasks to synchronize src repos to workspace directory
+  include_tasks: sync-project.yaml
   with_dict: "{{ zuul.projects }}"
   loop_control:
     loop_var: zj_project
-  delegate_to: localhost
-  # We occasionally see git pushes in the middle of this loop fail then
-  # subsequent pushes for other repos succeed. The entire loop ends up
-  # failing because one of the pushes failed. Mitigate this by retrying
-  # on failure.
-  register: git_push
-  until: git_push is success
-  retries: 3
-  # ANSIBLE0006: Skip linting since it triggers on the "git" command,
-  # but push is not supported by ansible git module.
-  tags:
-    - skip_ansible_lint
 
 # Do this as a multi-line shell so that we can do the loop once
 - name: Update remote repository state correctly

roles/prepare-workspace-git/tasks/sync-project.yaml

@@ -0,0 +1,23 @@
+- name: "Synchronize {{ zj_project.value.canonical_name }}"
+  command: |-
+    {% if ansible_connection == "kubectl" %}
+      git push {% if mirror_workspace_quiet %}--quiet{% endif %} --mirror "ext::kubectl --context {{ zuul.resources[inventory_hostname].context }} -n {{ zuul.resources[inventory_hostname].namespace }} exec -i {{ zuul.resources[inventory_hostname].pod }} -- %S {{ zuul_workspace_root }}/{{ zj_project.value.src_dir }}"
+    {% else %}
+      git push {% if mirror_workspace_quiet %}--quiet{% endif %} --mirror git+ssh://{{ ansible_user }}@{{ ansible_host | ipwrap }}:{{ ansible_port }}/{{ zuul_workspace_root }}/{{ zj_project.value.src_dir }}
+    {% endif %}
+  args:
+    chdir: "{{ zuul.executor.work_root }}/{{ zj_project.value.src_dir }}"
+  environment:
+    GIT_ALLOW_PROTOCOL: ext:ssh
+  delegate_to: localhost
+  # We occasionally see git pushes in the middle of this loop fail then
+  # subsequent pushes for other repos succeed. The entire loop ends up
+  # failing because one of the pushes failed. Mitigate this by retrying
+  # on failure.
+  register: git_push
+  until: git_push is success
+  retries: 3
+  # ANSIBLE0006: Skip linting since it triggers on the "git" command,
+  # but push is not supported by ansible git module.
+  tags:
+    - skip_ansible_lint