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: Ie16f861b9abdc5887365bb58c9eec427f55cb177

defaults/main.yml

@@ -142,6 +142,9 @@ ironic_node_name: ironic
 # regenerated each run.
 ironic_recreate_keys: False
 
+# venv_download, even when true, will use the fallback method of building the
+# venv from scratch if the venv download fails.
+ironic_venv_download: "{{ not ironic_developer_mode | bool }}"
 ironic_venv_download_url: http://127.0.0.1/venvs/untagged/ubuntu/ironic.tgz
 
 ironic_tftp_server_address: "{{ ansible_host }}"

tasks/ironic_install.yml

@@ -48,7 +48,7 @@
     dest: "/var/cache/{{ ironic_venv_download_url | basename }}"
     checksum: "sha1:{{ lookup('url', ironic_venv_download_url | replace('tgz', 'checksum')) }}"
   register: ironic_get_venv
-  when: not ironic_developer_mode | bool
+  when: ironic_venv_download | bool
 
 - name: Remove existing venv
   file:
@@ -61,15 +61,14 @@
     path: "{{ ironic_bin | dirname }}"
     state: directory
   register: ironic_venv_dir
+  when: ironic_get_venv | changed
 
 - name: Unarchive pre-built venv
   unarchive:
     src: "/var/cache/{{ ironic_venv_download_url | basename }}"
     dest: "{{ ironic_bin | dirname }}"
     copy: "no"
-  when:
-    - not ironic_developer_mode | bool
-    - ironic_get_venv | changed or ironic_venv_dir | changed
+  when: ironic_get_venv | changed
   notify: Restart ironic services
 
 - name: Install pip packages
@@ -86,7 +85,7 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  when: ironic_developer_mode | bool
+  when: ironic_get_venv | failed or ironic_get_venv | skipped
   notify: Restart ironic services
 
 - name: CentOS remove python from path first
@@ -95,12 +94,9 @@
     state: "absent"
   when:
     - ansible_pkg_mgr == 'yum'
-    - not ironic_developer_mode | bool
-    - ironic_get_venv | changed or ironic_venv_dir | changed
+    - ironic_get_venv | changed
 
 - name: Update virtualenv path
   command: >
     virtualenv-tools --update-path=auto --reinitialize {{ ironic_bin | dirname }}
-  when:
-    - not ironic_developer_mode | bool
-    - ironic_get_venv | changed or ironic_venv_dir | changed
+  when: ironic_get_venv | changed