# Recommended varnishncsa logging format: '%h %l %u %t "%m %{X-Forwarded-Proto}i://%{Host}i%U%q %H" %s %b "%{Referer}i" "%{User-agent}i"' vcl 4.1; import std; backend default { .host = "127.0.0.1"; .port = "4000"; } # ACL for IPs that are allowed to PURGE data from the cache acl purge { "127.0.0.1"; } sub vcl_recv { # Redirect HTTP to HTTPS if (std.port(server.ip) != 443) { set req.http.X-Forwarded-Proto = "http"; set req.http.x-redir = "https://" + req.http.host + req.url; return (synth(750, "")); } else { set req.http.X-Forwarded-Proto = "https"; } # CHUNKED SUPPORT if (req.http.Range ~ "bytes=") { set req.http.x-range = req.http.Range; } # Pipe if WebSockets request is coming through if (req.http.upgrade ~ "(?i)websocket") { return (pipe); } # Allow purging of the cache if (req.method == "PURGE") { if (!client.ip ~ purge) { return(synth(405,"Not allowed.")); } return(purge); } } sub vcl_backend_response { # gzip text content if (beresp.http.content-type ~ "(text|text/css|application/x-javascript|application/javascript)") { set beresp.do_gzip = true; } # Retry broken backend responses. if (beresp.status == 503) { set bereq.http.X-Varnish-Backend-503 = "1"; return (retry); } # CHUNKED SUPPORT if (bereq.http.x-range ~ "bytes=" && beresp.status == 206) { set beresp.ttl = 10m; set beresp.http.CR = beresp.http.content-range; } # Don't cache objects that require authentication if (beresp.http.Authorization && !beresp.http.Cache-Control ~ "public") { set beresp.uncacheable = true; return (deliver); } # Allow serving cached content for 6h in case backend goes down set beresp.grace = 6h; # Do not cache 5xx responses if (beresp.status == 500 || beresp.status == 502 || beresp.status == 503 || beresp.status == 504) { set beresp.uncacheable = true; return (abandon); } # Do not cache redirects and errors if ((beresp.status >= 300) && (beresp.status < 500)) { set beresp.uncacheable = true; set beresp.ttl = 30s; return (deliver); } } # The synthetic response for 301 redirects sub vcl_synth { if (resp.status == 750) { set resp.status = 301; set resp.http.Location = req.http.x-redir; return(deliver); } } # Ensure WebSockets through the pipe do not close prematurely sub vcl_pipe { if (req.http.upgrade) { set bereq.http.upgrade = req.http.upgrade; set bereq.http.connection = req.http.connection; } } sub vcl_hash { # CHUNKED SUPPORT if (req.http.x-range ~ "bytes=") { hash_data(req.http.x-range); unset req.http.Range; } } sub vcl_backend_fetch { # Be more lenient for slow servers on the fediverse if bereq.url ~ "^/proxy/" { set bereq.first_byte_timeout = 300s; } # CHUNKED SUPPORT if (bereq.http.x-range) { set bereq.http.Range = bereq.http.x-range; } if (bereq.retries == 0) { # Clean up the X-Varnish-Backend-503 flag that is used internally # to mark broken backend responses that should be retried. unset bereq.http.X-Varnish-Backend-503; } else { if (bereq.http.X-Varnish-Backend-503) { if (bereq.method != "POST" && std.healthy(bereq.backend) && bereq.retries <= 4) { # Flush broken backend response flag & try again. unset bereq.http.X-Varnish-Backend-503; } else { return (abandon); } } } } sub vcl_deliver { # CHUNKED SUPPORT if (resp.http.CR) { set resp.http.Content-Range = resp.http.CR; unset resp.http.CR; } } sub vcl_backend_error { # Retry broken backend responses. set bereq.http.X-Varnish-Backend-503 = "1"; return (retry); }