nginx.conf.template

###############################################################################################
# https://gist.github.com/seabbs/721d95b6950461da8624378193305665
###############################################################################################

# If we receive X-Forwarded-Proto, pass it through; otherwise, pass along the
# scheme used to connect to this server
map $http_x_forwarded_proto $proxy_x_forwarded_proto {
  default $http_x_forwarded_proto;
  ''      $scheme;
}

# If we receive X-Forwarded-Port, pass it through; otherwise, pass along the
# server port the client connected to
map $http_x_forwarded_port $proxy_x_forwarded_port {
  default $http_x_forwarded_port;
  ''      $server_port;
}

# If we receive Upgrade, set Connection to "upgrade"; otherwise, delete any
# Connection header that may have been passed to this server
map $http_upgrade $proxy_connection {
  default upgrade;
  '' close;
}

# Set appropriate X-Forwarded-Ssl header
map $scheme $proxy_x_forwarded_ssl {
  default off;
  https on;
}

proxy_http_version 1.1;
proxy_buffering off;
proxy_set_header Host $http_host;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $proxy_connection;
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 $proxy_x_forwarded_proto;
proxy_set_header X-Forwarded-Ssl $proxy_x_forwarded_ssl;
proxy_set_header X-Forwarded-Port $proxy_x_forwarded_port;
proxy_set_header Proxy "";

###############################################################################################

server {

  # Minimal
  listen 8080;

  # SSL, self-signed
  listen 8443 ssl;
  ssl_certificate /etc/nginx/certs/selfsigned.crt;
  ssl_certificate_key /etc/nginx/certs/selfsigned.key;

  # Healthcheck
  location = /healthcheck {
    access_log off;
    default_type text/plain;
    return 200 "healthy\n";
  }

  # Backend
  location = ${BACKEND_PATH}i {
    # Fix auto-generated Location's that don't respect forwarded values
    return 301 $proxy_x_forwarded_proto://$http_host${BACKEND_PATH}/;
  }
  location ${BACKEND_PATH}/ {
    proxy_set_header X-Upstream-Id backend;
    resolver ${DNS_RESOLVER} valid=5s;
    set $upstream ${BACKEND_URL}$request_uri;
    proxy_pass $upstream;
  }

  # Frontend
  location / {
    proxy_set_header X-Upstream-Id frontend;
    resolver ${DNS_RESOLVER} valid=5s;
    set $upstream ${FRONTEND_URL}$request_uri;
    proxy_pass $upstream;
  }

}