map $http_upgrade $connection_upgrade {
  default upgrade;
  ''      close;
}

upstream backend {
    server web:3000 fail_timeout=0;
}

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=CACHE:10m inactive=7d max_size=1g;

server {
  listen 80;
  listen [::]:80;
  server_name dev.example;
  location /.well-known/acme-challenge/ { allow all; }
  location / { return 301 https://$host$request_uri; }
}

server {
  listen 443 ssl http2;
  listen [::]:443 ssl http2;
  server_name dev.example;

  ssl_protocols TLSv1.2 TLSv1.3;

  # You can use https://ssl-config.mozilla.org/ to generate your cipher set.
  # We recommend their "Intermediate" level.
  ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-CHACHA20-POLY1305;

  ssl_prefer_server_ciphers on;
  ssl_session_cache shared:SSL:10m;
  ssl_session_tickets off;

  # Uncomment these lines once you acquire a certificate:
  # ssl_certificate     /etc/letsencrypt/live/example.com/fullchain.pem;
  # ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;

  # Or uncomment these lines to use a celf-signed certificate:
  # ssl_certificate     /etc/ssl/certs/nginx-selfsigned.crt;
  # ssl_certificate_key /etc/ssl/private/nginx-selfsigned.key;

  keepalive_timeout    70;
  sendfile             on;
  client_max_body_size 99m;

  gzip on;
  gzip_disable "msie6";
  gzip_vary on;
  gzip_proxied any;
  gzip_comp_level 6;
  gzip_buffers 16 8k;
  gzip_http_version 1.1;
  gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript image/svg+xml image/x-icon;

  location / {
    try_files $uri @proxy;
  }

  location @proxy {
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_set_header Proxy "";
    proxy_pass_header Server;

    proxy_pass http://backend;
    proxy_buffering on;
    proxy_redirect off;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;

    proxy_cache CACHE;
    proxy_cache_valid 200 7d;
    proxy_cache_valid 410 24h;
    proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
    add_header X-Cached $upstream_cache_status;

    tcp_nodelay on;
  }

  error_page 404 500 501 502 503 504 /500.html;
}