I configured an Apache2 on Ubuntu Server 16.04 as an http reverse proxy to an external web server.
There's something very curious here, as pages are loaded, some of its resources (.css, .js) return 404, not all the time, but randomly.
To try to figure out what's happening I checked with cURL from inside this server using curl -v -k "https://127.0.0.1:443/proxyed_path/css/resource.css" and found as I already knew sometimes I got correct results but when I execute this command repeatedly I get the google 404 error.
This is the error I'm getting:
> Host: 127.0.0.1
> User-Agent: curl/7.47.0
> Accept: */*
>
< HTTP/1.1 404 Not Found
< Date: Thu, 11 Apr 2019 23:42:44 GMT
< Server: sffe
< Content-Type: text/html; charset=UTF-8
< X-Content-Type-Options: nosniff
< Content-Length: 1594
< X-XSS-Protection: 0
< Access-Control-Allow-Origin: *
<
<!DOCTYPE html>
<html lang=en>
<meta charset=utf-8>
<meta name=viewport content="initial-scale=1, minimum-scale=1, width=device-width">
<title>Error 404 (Not Found)!!1</title>
<style>
*{margin:0;padding:0}html,code{font:15px/22px arial,sans-serif}html{background:#fff;color:#222;padding:15px}body{margin:7% auto 0;max-width:390px;min-height:180px;padding:30px 0 15px}* > body{background:url(//www.google.com/images/errors/robot.png) 100% 5px no-repeat;padding-right:205px}p{margin:11px 0 22px;overflow:hidden}ins{color:#777;text-decoration:none}a img{border:0}@media screen and (max-width:772px){body{background:none;margin-top:0;max-width:none;padding-right:0}}#logo{background:url(//www.google.com/images/branding/googlelogo/1x/googlelogo_color_150x54dp.png) no-repeat;margin-left:-5px}@media only screen and (min-resolution:192dpi){#logo{background:url(//www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png) no-repeat 0% 0%/100% 100%;-moz-border-image:url(//www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png) 0}}@media only screen and (-webkit-min-device-pixel-ratio:2){#logo{background:url(//www.google.com/images/branding/googlelogo/2x/googlelogo_color_150x54dp.png) no-repeat;-webkit-background-size:100% 100%}}#logo{display:inline-block;height:54px;width:150px}
</style>
<a href=//www.google.com/><span id=logo aria-label=Google></span></a>
<p><b>404.</b> <ins>That’s an error.</ins>
<p>The requested URL <code>/js/ui-bootstrap-tpls-1.3.1.min.js</code> was not found on this server. <ins>That’s all we know.</ins>
How can be Google responding my requests?, could it be that the site (a hospital) have a firewall doing some nasty things?.
/js/ui-bootstrap-tpls-1.3.1.min.js(angularjs)? It might just be reading it from the wrong domain, or it's loading a version from an old path.http://google.com/js/ui-bootstrap-tpls-1.3.1.min.jsafter too many requests. Can you confirm it's a throttling thing by doing a bunch of quick curl requests to see if they all fail, and then the same number of requests over a long span of time to see if they all succeed? Do you see in the apache logs that during this request you're getting to the correct page?