Make Glance standalone-ness a separate flag

Full Glance functionality requires Glance being run in a configuration
where it can spawn long-running task threads. The default uwsgi mode
does not allow this, and the current workaround is to set WSGI_MODE
to something other than uwsgi to get the devstack code to deploy
Glance as a standalone service. Since this affects the entire rest of
the deployment, this patch separates out a flag to control this behavior
specifically for Glance. When WSGI_MODE=uwsgi, control of the Glance
deployment mechanism is allowed via GLANCE_STANDALONE=True|False. If
WSGI_MODE!= uwsgi then we deploy standalone Glance anyway.

Change-Id: I79068ce0bd7414bc48ff534ee22f0de5d7b091cb

functions

@@ -103,10 +103,10 @@ function _upload_image {
     done
 
     if [[ "$GLANCE_USE_IMPORT_WORKFLOW" == "True" ]]; then
-        if [[ "$WSGI_MODE" != "uwsgi" ]]; then
+        if [[ "$GLANCE_STANDALONE" == "True" ]]; then
             useimport="--import"
         else
-            echo "*** Unable to use glance import workflow because WSGI_MODE=uwsgi! ***"
+            echo "*** Unable to use glance import workflow because glance is not standalone! ***"
         fi
     fi
 

lib/apache

@@ -372,6 +372,25 @@ function write_local_uwsgi_http_config {
     restart_apache_server
 }
 
+# Write a straight-through proxy for a service that runs locally and just needs
+# to be reachable via the main http proxy at $loc
+function write_local_proxy_http_config {
+    local name=$1
+    local url=$2
+    local loc=$3
+    local apache_conf
+    apache_conf=$(apache_site_config_for $name)
+
+    enable_apache_mod proxy
+    enable_apache_mod proxy_http
+
+    echo "KeepAlive Off" | sudo tee $apache_conf
+    echo "SetEnv proxy-sendchunked 1" | sudo tee -a $apache_conf
+    echo "ProxyPass \"${loc}\" \"$url\" retry=0 " | sudo tee -a $apache_conf
+    enable_apache_site $name
+    restart_apache_server
+}
+
 function remove_uwsgi_config {
     local file=$1
     local wsgi=$2

lib/glance

@@ -55,6 +55,13 @@ GLANCE_DEFAULT_BACKEND=${GLANCE_DEFAULT_BACKEND:-fast}
 
 GLANCE_CACHE_DIR=${GLANCE_CACHE_DIR:=$DATA_DIR/glance/cache}
 
+# Full Glance functionality requires running in standalone mode. If we are
+# not in uwsgi mode, then we are standalone, otherwise allow separate control.
+if [[ "$WSGI_MODE" != "uwsgi" ]]; then
+    GLANCE_STANDALONE=True
+fi
+GLANCE_STANDALONE=${GLANCE_STANDALONE:-False}
+
 # File path for each store specified in GLANCE_MULTIPLE_FILE_STORES, the store
 # identifier will be appended to this path at runtime. If GLANCE_MULTIPLE_FILE_STORES
 # has fast,cheap specified then filepath will be generated like $DATA_DIR/glance/fast
@@ -240,9 +247,10 @@ function configure_glance {
         iniset $GLANCE_CACHE_CONF DEFAULT cinder_endpoint_template "https://$CINDER_SERVICE_HOST:$CINDER_SERVICE_PORT/v3/%(project_id)s"
     fi
 
-    if [[ "$WSGI_MODE" == "uwsgi" ]]; then
+    if [[ "$GLANCE_STANDALONE" == False ]]; then
         write_local_uwsgi_http_config "$GLANCE_UWSGI_CONF" "$GLANCE_UWSGI" "/image"
     else
+        write_local_proxy_http_config glance "http://$GLANCE_SERVICE_HOST:$GLANCE_SERVICE_PORT_INT" "/image"
         iniset $GLANCE_API_CONF DEFAULT bind_host $GLANCE_SERVICE_LISTEN_ADDRESS
         iniset $GLANCE_API_CONF DEFAULT workers "$API_WORKERS"
     fi
@@ -342,7 +350,7 @@ function start_glance {
         fi
     fi
 
-    if [[ "$WSGI_MODE" == "uwsgi" ]]; then
+    if [[ "$GLANCE_STANDALONE" == False ]]; then
         run_process g-api "$(which uwsgi) --procname-prefix glance-api --ini $GLANCE_UWSGI_CONF"
     else
         run_process g-api "$GLANCE_BIN_DIR/glance-api --config-dir=$GLANCE_CONF_DIR"