Use uwsgi for nova when NOVA_USE_MOD_WSGI is not False

Unless NOVA_USE_MOD_WSGI is False, run nova-api and nova-metadata
using uwsgi.

Because the metadata server is always expected to run on a port and
without a prefix, we have it configured to use uwsgi but not to
proxy from apache: uwsgi listens on the configured port itself.

uwsgi process that listen themselve do not need a socket or to
chmod-socket, so those config lines have been moved to the block
that is also writing proxy configuration for apache.

Because this change only uses uwsgi for nova-api and nova-api-meta,
nova-api-meta is set to default to enabled in stackrc because the
nova-api wsgi application used by wsgi only presents the one service
(osapi_compute).

If NOVA_USE_MOD_WSGI is False and tls_proxy service is enabled,
nova-api is run on an internal port reached via the tls_proxy.

Depends-On: I8ff08d61520ccf04e32dcd02f4cecc39dae823cb
Change-Id: If2d7e363a6541854f2e30c03171bef7a41aff745

lib/apache

@@ -250,7 +250,6 @@ function write_uwsgi_config {
     # always cleanup given that we are using iniset here
     rm -rf $file
     iniset "$file" uwsgi wsgi-file "$wsgi"
-    iniset "$file" uwsgi socket "$socket"
     iniset "$file" uwsgi processes $API_WORKERS
     # This is running standalone
     iniset "$file" uwsgi master true
@@ -267,7 +266,6 @@ function write_uwsgi_config {
     iniset "$file" uwsgi add-header "Connection: close"
     # This ensures that file descriptors aren't shared between processes.
     iniset "$file" uwsgi lazy-apps true
-    iniset "$file" uwsgi chmod-socket 666
 
     # If we said bind directly to http, then do that and don't start the apache proxy
     if [[ -n "$http" ]]; then
@@ -276,6 +274,8 @@ function write_uwsgi_config {
         local apache_conf=""
         apache_conf=$(apache_site_config_for $name)
         echo "SetEnv proxy-sendcl 1" | sudo tee $apache_conf
+        iniset "$file" uwsgi socket "$socket"
+        iniset "$file" uwsgi chmod-socket 666
         echo "ProxyPass \"${url}\" \"unix:${socket}|uwsgi://uwsgi-uds-${name}/\" retry=0 " | sudo tee -a $apache_conf
         enable_apache_site $name
         restart_apache_server