Rename env var to APP_UPSTREAM

src/web-nginx/Dockerfile

@@ -5,8 +5,8 @@ HEALTHCHECK CMD curl --fail http://localhost/tt-rss/index.php || exit 1
 COPY nginx.conf /etc/nginx/templates/nginx.conf.template
 
 # By default, nginx will send the php requests to "app" server, but this server
-# name can be overridden at runtime by passing an APP_SERVERNAME env var
+# name can be overridden at runtime by passing an APP_UPSTREAM env var
-ENV APP_SERVERNAME=${APP_SERVERNAME:-app}
+ENV APP_UPSTREAM=${APP_UPSTREAM:-app}
 
 # It's necessary to set the following NGINX_ENVSUBST_OUTPUT_DIR env var to tell
 # nginx to replace the env vars of /etc/nginx/templates/nginx.conf.template

src/web-nginx/nginx.conf

@@ -17,7 +17,7 @@ http {
 	index index.php;
 
 	upstream app {
-		server ${APP_SERVERNAME}:9000;
+		server ${APP_UPSTREAM}:9000;
 	}
 
 	server {