default.conf

resolver                   172.16.0.23 valid=300s;
resolver_timeout           10s;
proxy_cache_path           /tmp/cache levels=1:2 keys_zone=S3CACHE:10m inactive=48h max_size=1000m;
proxy_temp_path            /tmp/cache/temp;
server {
  listen       80;
  server_name  localhost;
  location / {
    try_files $uri @s3cache;
  }

  location @s3cache{ 
    proxy_cache            S3CACHE;
    proxy_cache_valid      200 48h;
    proxy_cache_valid      403 60m;
    proxy_pass http://<bucket>.s3.amazonaws.com;
  }

}

Dockerfile

FROM nginx
RUN rm /etc/nginx/conf.d/default.conf
COPY default.conf /etc/nginx/conf.d/default.conf
EXPOSE 80
CMD ["nginx", "-g", "daemon off;"]

haproxy.cfg

global
  log 127.0.0.1 local0 notice
  maxconn 2000
  user haproxy
  group haproxy

listen appname 0.0.0.0:80
  mode http
  stats enable
  cookie SRVNAME insert
  balance source
  option httpclose
  option forwardfor
  server server1 <server ip>:80 check
  server server2 <server ip>:80 check

listen stats 0.0.0.0:8080
  mode http
  log global
  stats enable
  stats auth admin:password
  stats uri  /haproxy?stats