moving to environment variables

docker-compose.yml

@@ -4,16 +4,19 @@ networks:
 
 services:
   nginx:
+    build:
+      context: ./nginx
+      dockerfile: Dockerfile
     container_name: nginx
+    environment:
+      BACKEND_HOST: "${BACKEND_HOST}" # from .env
     restart: unless-stopped
-    image: nginx
     networks:
       - app-network
     ports:
       - 80:80
       - 443:443
     volumes:
-      - ./nginx/nginx.conf:/etc/nginx/nginx.conf
       - ./certbot/conf:/etc/letsencrypt
       - ./certbot/www:/var/www/certbot
       - ./html/:/etc/nginx/html:ro

nginx/Dockerfile

@@ -0,0 +1,13 @@
+FROM nginx:latest
+
+
+# Copy template config
+COPY nginx.conf.template /etc/nginx/nginx.conf.template
+
+# Update package list and install gettext-base
+RUN apt-get update && apt-get install -y gettext-base
+
+# Replace variables at build time
+ENV BACKEND_HOST=backend
+
+CMD /bin/sh -c "envsubst '\$BACKEND_HOST' < /etc/nginx/nginx.conf.template > /etc/nginx/nginx.conf && nginx -g 'daemon off;'"

nginx/nginx.conf.template

@@ -38,7 +38,7 @@ http {
         }
 
         location /posts/ {
-            proxy_pass http://backend:8080/posts;
+            proxy_pass http://$BACKEND_HOST:8080/posts;
             proxy_set_header Host $host;
             proxy_set_header X-Real-IP $remote_addr;
             proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;