export app config vars into sigil environment for use in nginx templates. closes #2149

docs/nginx.md

@@ -69,6 +69,8 @@ server {
 {{ .SSL_SERVER_NAME }}              List of SSL VHOSTS
 ```
 
+> NOTE: Application config variables are available for use in custom templates. To do so, use the form of `{{ var "FOO" }}` to access a variable named `FOO`.
+
 
 ### Example HTTP to HTTPS Custom Template
 Use case: a simple dockerfile app that includes `EXPOSE 80`

plugins/nginx-vhosts/functions

@@ -188,6 +188,7 @@ nginx_build_config() {
       fi
       local SSL_SERVER_NAME=$(echo "$SSL_VHOSTS" | xargs)
     fi
+    eval "$(config_export app "$APP")"
     local SIGIL_PARAMS=(-f $NGINX_TEMPLATE APP="$APP" DOKKU_ROOT="$DOKKU_ROOT"
           NOSSL_SERVER_NAME="$NOSSL_SERVER_NAME"
           DOKKU_APP_LISTENERS="$DOKKU_APP_LISTENERS"