pass REMARK_URL as arg to frontend part during build time

Dockerfile

@@ -17,6 +17,9 @@ RUN go build -o remark -ldflags "-X main.revision=$(git rev-parse --abbrev-ref H
 
 FROM node:9.4-alpine as build-frontend
 
+ARG REMARK_URL
+ENV REMARK_URL $REMARK_URL
+
 ADD web /srv/web
 RUN \
     cd /srv/web && \

docker-compose.yml

@@ -2,7 +2,10 @@ version: '2'
 
 services:
     remark:
-        build: .
+        build:
+          context: .
+          args:
+            - REMARK_URL=${REMARK_URL}
         image: umputun/remark:master
         container_name: "remark"
         hostname: "remark"