add support for configuring server url. fixes #11

docker/Dockerfile

@@ -2,5 +2,12 @@ FROM nginx:alpine
 
 EXPOSE 80
 
+RUN apk add gettext
 COPY docker/nginx.conf /etc/nginx/conf.d/default.conf
+COPY docker/env.js.template /env.js.template
+COPY docker/docker-entrypoint.sh /docker-entrypoint.sh
+RUN chmod +x /docker-entrypoint.sh
 COPY dist/ /var/www/html/
+
+ENTRYPOINT ["/docker-entrypoint.sh"]
+CMD ["nginx", "-g", "daemon off;"]

docker/docker-entrypoint.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+set -e
+envsubst < env.js.template > /var/www/html/env.js
+exec "$@"

docker/env.js.template

@@ -0,0 +1,3 @@
+window.env = {
+  SERVER_URL: "$SERVER_URL",
+}

docker/nginx.conf

@@ -17,4 +17,8 @@ server {
   location = /index.html {
     add_header 'Cache-Control' 'no-cache';
   }
+
+  location = /env.js {
+    add_header 'Cache-Control' 'no-cache';
+  }
 }