use intermediate image to eval nginx.conf.tmpl at build time

docker-compose.yml

@@ -4,9 +4,9 @@ services:
     build: ./nginx/
     container_name: webserver
     volumes:
-      - type: bind
-        source: ./nginx/nginx.conf
-        target: /etc/nginx/nginx.conf
+      # - type: bind
+        # source: ./nginx/nginx.conf
+        # target: /etc/nginx/nginx.conf
       - ./nginx/log/:/var/log/nginx/
       - /etc/letsencrypt/:/etc/letsencrypt/
     ports:

nginx/Dockerfile

@@ -1,5 +1,13 @@
-FROM nginx
+FROM ruby as template
+
+ADD "nginx.conf.tmpl" "nginx.yaml" "/build/"
+RUN gem install mustache \
+      && cd /build \
+      && mustache nginx.yaml nginx.conf.tmpl > nginx.conf
+
+
+FROM nginx:latest
+#RUN apt-get update && apt-get install --no-install-recommends --no-install-suggests -y libnginx-mod-stream
+COPY --from=template /build/nginx.conf /etc/nginx/nginx.conf
 
-RUN apt-get update \
-      && apt-get install --no-install-recommends --no-install-suggests -y libnginx-mod-stream