如何自定义 503 错误 - varnish 4

Question

如何自定义 Varnish 4 的“503 backend fetch failed”？

我正在自定义其他错误，当它们通过合成阶段时：

sub vcl_synth {
    if (resp.status == 750) {
        set resp.http.location = "http://mobile.cronica.com.ar/";
        set resp.status = 302;
        set resp.http.Action = "Redirect";  
        return(deliver);
    }
    if (resp.status == 751) {
        set resp.status = 301;
        set resp.http.location = "http://www." + req.http.host + req.url;
        set resp.http.Action = "Redirect";
        return(deliver);
    }
    else {
         synthetic( {"
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
  <head>
    <title>"} + resp.status + " " + resp.reason + {"</title>
    <link href='http://fonts.googleapis.com/css?family=Oswald:400,700' rel='stylesheet' type='text/css'>

  </head>
  <body style="background-color:#444; font-family: 'Oswald', sans-serif;">
    <h1 style="color:#DD8363;">Error "} + resp.status + " " + {"</h1>
    <p style="color:#5F88C4; ">"} + resp.reason + {"</p>
    <h3 style="color:white;">CEPI Says</h3>
    <p style="color:#bdb76b;">XID: "} + req.xid + {"</p>
    <p style="color:#bdb76b;">Edge-Server: "} + server.hostname + {"</p>
    <hr>
    <p style="color:#65b042;">2.0</p>
  </body>
</html>
"} ); 
        return(deliver);
    }

}

但 503 错误似乎避免了这种情况。

Answer 1

根据Varnish Processing States control after backend_error() should be passed to vcl_synth(), but in reality the error page you are seeing is delivered unconditionally in backend_error() of builtin.vcl。您要么在那里自定义您的网页，要么在您的 vcl 中添加 sub vcl_backend_error { return(retry); } 以强制跳转到 vcl_synth()，这将包含 resp.status = 503.

如何自定义 503 错误 - varnish 4

how to customize 503 error - varnish 4

error-handling

varnish

http-status-code-503

varnish-vcl