stop non-localhost HTTP access, define proxy for http requests

nginx.conf

@@ -1,5 +1,5 @@
 worker_processes ${{NUM_WORKERS}};
-error_log stderr notice;
+error_log stderr notice; # PROBLEM
 daemon on;
 pid logs/nginx.pid;
 
@@ -8,19 +8,54 @@ events {
 }
 
 http {
+  charset UTF-8;
   include mime.types;
 
+  server_tokens off;
+
+  # blocking non-local requests
+  geo $bad_client {
+    default 1;
+    127.0.0.1 0;
+  }
+
   server {
     listen ${{PORT}};
     lua_code_cache ${{CODE_CACHE}};
 
+    if ($bad_client) {
+      return 301 https://${{DOMAIN}}/$request_uri; #permanent
+    }
+
     location / {
       default_type text/html;
+      set $_url "";
       content_by_lua '
         require("lapis").serve("app")
       ';
     }
 
+    location /proxy {
+      internal;
+      rewrite_by_lua "
+        local req = ngx.req
+        for k,v in pairs(req.get_headers()) do
+          if k ~= 'content-length' then
+            req.clear_header(k)
+          end
+        end
+        if ngx.ctx.headers then
+          for k,v in pairs(ngx.ctx.headers) do
+            req.set_header(k, v)
+          end
+        end
+      ";
+
+      resolver 8.8.8.8;
+      proxy_http_version 1.1;
+      proxy_pass $_url;
+    }
+
     location /static/ {
       alias static/;
     }