Allow venv python interpreter to be overridden

Change-Id: I31d0d5bb3f65006a8b4b617aba70c3524df6e255

defaults/main.yml

@@ -18,6 +18,7 @@ debug: False
 
 # Set installation method
 glance_install_method: "source"
+glance_venv_python_executable: "{{ openstack_venv_python_executable | default('python2') }}"
 
 # Set the host which will execute the shade modules
 # for the service setup. The host must already have

tasks/glance_install.yml

@@ -129,6 +129,7 @@
   import_role:
     name: "python_venv_build"
   vars:
+    venv_python_executable: "{{ glance_venv_python_executable }}"
     venv_build_constraints: "{{ glance_git_constraints }}"
     venv_build_distro_package_list: "{{ glance_devel_distro_packages }}"
     venv_install_destination_path: "{{ glance_bin | dirname }}"