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: I7ac0d8e732f0e97bf667e4428238acc2dc8bee0b

defaults/main.yml

@@ -36,6 +36,9 @@ aodh_developer_constraints:
 aodh_venv_tag: untagged
 aodh_bin: "/openstack/venvs/aodh-{{ aodh_venv_tag }}/bin"
 
+# venv_download, even when true, will use the fallback method of building the
+# venv from scratch if the venv download fails.
+aodh_venv_download: "{{ not aodh_developer_mode | bool }}"
 # URL of the pre-built virtualenv
 aodh_venv_download_url: http://127.0.0.1/venvs/untagged/ubuntu/aodh.tgz
 

tasks/aodh_install.yml

@@ -68,7 +68,7 @@
     dest: "/var/cache/{{ aodh_venv_download_url | basename }}"
     checksum: "sha1:{{ lookup('url', aodh_venv_download_url | replace('tgz', 'checksum')) }}"
   register: aodh_get_venv
-  when: not aodh_developer_mode | bool
+  when: aodh_venv_download | bool
 
 - name: Remove existing venv
   file:
@@ -82,18 +82,14 @@
     state: directory
     mode: "0755"
   register: aodh_venv_dir
-  when:
-    - not aodh_developer_mode | bool
-    - aodh_get_venv | changed
+  when: aodh_get_venv | changed
 
 - name: Unarchive pre-built venv
   unarchive:
     src: "/var/cache/{{ aodh_venv_download_url | basename }}"
     dest: "{{ aodh_bin | dirname }}"
     copy: "no"
-  when:
-    - not aodh_developer_mode | bool
-    - aodh_get_venv | changed or aodh_venv_dir | changed
+  when: aodh_get_venv | changed
   notify: Restart aodh services
 
 - name: Install pip packages
@@ -110,7 +106,7 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  when: aodh_developer_mode | bool
+  when: aodh_get_venv | failed or aodh_get_venv | skipped
   notify: Restart aodh services
 
 - name: CentOS remove python from path first
@@ -119,12 +115,9 @@
     state: "absent"
   when:
     - ansible_pkg_mgr == 'yum'
-    - not aodh_developer_mode | bool
-    - aodh_get_venv | changed or aodh_venv_dir | changed
+    - aodh_get_venv | changed
 
 - name: Update virtualenv path
   command: >
     virtualenv-tools --update-path=auto --reinitialize {{ aodh_bin | dirname }}
-  when:
-    - not aodh_developer_mode | bool
-    - aodh_get_venv | changed or aodh_venv_dir | changed
+  when: aodh_get_venv | changed