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: I2df5a50be52e39809965f8b5c0b5dcbc3ddabc86

defaults/main.yml

@@ -37,6 +37,9 @@ glance_bin: "/openstack/venvs/glance-{{ glance_venv_tag }}/bin"
 #  glance_etc_dir: "/usr/local/etc/glance"
 glance_etc_dir: "{{ glance_bin | dirname }}/etc/glance"
 
+# venv_download, even when true, will use the fallback method of building the
+# venv from scratch if the venv download fails.
+glance_venv_download: "{{ not glance_developer_mode | bool }}"
 glance_venv_download_url: http://127.0.0.1/venvs/untagged/ubuntu/glance.tgz
 
 # Enable/Disable Ceilometer

tasks/glance_install.yml

@@ -57,7 +57,7 @@
     dest: "/var/cache/{{ glance_venv_download_url | basename }}"
     checksum: "sha1:{{ lookup('url', glance_venv_download_url | replace('tgz', 'checksum')) }}"
   register: glance_get_venv
-  when: not glance_developer_mode | bool
+  when: glance_venv_download | bool
 
 - name: Remove existing venv
   file:
@@ -70,15 +70,14 @@
     path: "{{ glance_bin | dirname }}"
     state: directory
   register: glance_venv_dir
+  when: glance_get_venv | changed
 
 - name: Unarchive pre-built venv
   unarchive:
     src: "/var/cache/{{ glance_venv_download_url | basename }}"
     dest: "{{ glance_bin | dirname }}"
     copy: "no"
-  when:
-    - not glance_developer_mode | bool
-    - glance_get_venv | changed or glance_venv_dir | changed
+  when: glance_get_venv | changed
   notify:
     - Restart glance services
 
@@ -96,7 +95,7 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  when: glance_developer_mode | bool
+  when: glance_get_venv | failed or glance_get_venv | skipped
   notify:
     - Restart glance services
 
@@ -106,12 +105,9 @@
     state: "absent"
   when:
     - ansible_pkg_mgr == 'yum'
-    - not glance_developer_mode | bool
-    - glance_get_venv | changed or glance_venv_dir | changed
+    - glance_get_venv | changed
 
 - name: Update virtualenv path
   command: >
     virtualenv-tools --update-path=auto --reinitialize {{ glance_bin | dirname }}
-  when:
-    - not glance_developer_mode | bool
-    - glance_get_venv | changed or glance_venv_dir | changed
+  when: glance_get_venv | changed