client/docker: improved Dockerfile

client/Dockerfile

@@ -11,19 +11,21 @@ ARG CLIENT_BUILD_ARGS=""
 RUN BASE_URL="__BASEURL__" node build.js --gzip ${CLIENT_BUILD_ARGS}
 
 
-FROM nginx:alpine
+FROM scratch as approot
+
+COPY docker-start.sh /
+
+WORKDIR /etc/nginx
+COPY nginx.conf.docker ./nginx.conf
+
 WORKDIR /var/www
-
-RUN \
-    # Create init file
-    echo "#!/bin/sh" >> /init && \
-    echo 'sed -i "s|__BACKEND__|${BACKEND_HOST}|" /etc/nginx/nginx.conf' >> /init && \
-    echo 'sed -i "s|__BASEURL__|${BASE_URL:-/}|g" /var/www/index.htm /var/www/manifest.json' >> /init && \
-    echo 'exec nginx' >> /init && \
-    chmod a+x /init
-
-CMD ["/init"]
-VOLUME ["/data"]
-
-COPY nginx.conf.docker /etc/nginx/nginx.conf
 COPY --from=builder /opt/app/public/ .
+
+
+FROM nginx:alpine
+
+RUN apk --no-cache add dumb-init
+COPY --from=approot / /
+
+CMD ["/docker-start.sh"]
+VOLUME ["/data"]