Clean up developer mode logic

Fixes the ability to deploy a venv in cases where:
1) developer_mode is not enabled
2) A cached venv is not downloaded from the repo server

Additional cleanup to the developer_mode venv deployment
logic is implemented by adding a *_venv_download var
which is used to decouple developer_mode from the
cached venv extraction process so that a deployer
can force venv builds in-place (disable cached
venv usage) without enabling developer mode
constraints.

Change-Id: Id9571a51b3b3e0403eb51a01994a88f387ebfa9e

defaults/main.yml

@@ -28,6 +28,9 @@ cinder_developer_constraints:
 cinder_venv_tag: untagged
 cinder_bin: "/openstack/venvs/cinder-{{ cinder_venv_tag }}/bin"
 
+# venv_download, even when true, will use the fallback method of building the
+# venv from scratch if the venv download fails.
+cinder_venv_download: "{{ not cinder_developer_mode | bool }}"
 cinder_venv_download_url: http://127.0.0.1/venvs/untagged/ubuntu/cinder.tgz
 
 # Enable/Disable Ceilometer

tasks/cinder_install.yml

@@ -82,7 +82,7 @@
     dest: "/var/cache/{{ cinder_venv_download_url | basename }}"
     checksum: "sha1:{{ lookup('url', cinder_venv_download_url | replace('tgz', 'checksum')) }}"
   register: cinder_get_venv
-  when: not cinder_developer_mode | bool
+  when: cinder_venv_download | bool
 
 - name: Remove existing venv
   file:
@@ -95,18 +95,14 @@
     path: "{{ cinder_bin | dirname }}"
     state: directory
   register: cinder_venv_dir
-  when:
-    - not cinder_developer_mode | bool
-    - cinder_get_venv | changed
+  when: cinder_get_venv | changed
 
 - name: Unarchive pre-built venv
   unarchive:
     src: "/var/cache/{{ cinder_venv_download_url | basename }}"
     dest: "{{ cinder_bin | dirname }}"
     copy: "no"
-  when:
-    - not cinder_developer_mode | bool
-    - cinder_get_venv | changed or cinder_venv_dir | changed
+  when: cinder_get_venv | changed
   notify: Restart cinder services
 
 - name: Install pip packages
@@ -123,7 +119,7 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  when: cinder_developer_mode | bool
+  when: cinder_get_venv | failed or cinder_get_venv | skipped
   notify: Restart cinder services
 
 - name: CentOS remove python from path first
@@ -132,12 +128,9 @@
     state: "absent"
   when:
     - ansible_pkg_mgr == 'yum'
-    - not cinder_developer_mode | bool
-    - cinder_get_venv | changed or cinder_venv_dir | changed
+    - cinder_get_venv | changed
 
 - name: Update virtualenv path
   command: >
     virtualenv-tools --update-path=auto --reinitialize {{ cinder_bin | dirname }}
-  when:
-    - not cinder_developer_mode | bool
-    - cinder_get_venv | changed or cinder_venv_dir | changed
+  when: cinder_get_venv | changed