Add CNAME option

When a repo have a CNAME file, it will use the URL on it to map the server_name on ngnix

dokku

@@ -63,6 +63,12 @@ case "$1" in
       docker inspect $oldid &> /dev/null && docker kill $oldid > /dev/null
     fi
 
+    # CNAME
+    CNAME=$(docker run -i $IMAGE /bin/bash -c "if [[ -f /app/CNAME ]];then cat /app/CNAME; fi")
+    if [[ -n "$CNAME" ]]; then
+      echo "$CNAME" > "$DOKKU_ROOT/$APP/CNAME"
+    fi
+
     # start the app
     DOCKER_ARGS=$(: | pluginhook docker-args $APP)
     id=$(docker run -d -p 5000 -e PORT=5000 $DOCKER_ARGS $IMAGE /bin/bash -c "/start web")

plugins/nginx-vhosts/post-deploy

@@ -25,6 +25,10 @@ EOF
     SSL_DIRECTIVES=""
   fi
 
+  if [[ -f "$DOKKU_ROOT/$APP/CNAME" ]]; then
+    hostname=$(< "$DOKKU_ROOT/$APP/CNAME" )
+  fi
+
   # ssl based nginx.conf
   if [[ -n "$SSL_INUSE" ]]; then
   cat<<EOF > $DOKKU_ROOT/$APP/nginx.conf