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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Verdana","sans-serif"">Hi<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">I've got an issue where nginx (see below for version/compile options) returns a 405 (not allowed) to POST requests to clients when the upstream proxy returns
a 503.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">I know nginx doesn't allow posts to static content, but since all content (even static js, png etc) is served by upstream I cannot really understand why this
happens since everything from upstream ought to be dynamic.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">My config is basicly this<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> location / {<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> root /somewhere/;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> try_files /offline.html @xact;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> add_header Cache-Control "no-cache, max-age=0, no-store, must-revalidate";<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> }<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> location @xact {<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> proxy_pass http://127.0.0.1:4431;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> proxy_redirect default;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> proxy_set_header X-Real-IP $remote_addr;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> proxy_set_header X-Forwarded-Proto $scheme;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> proxy_set_header X-Forwarded-Host $host;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> proxy_read_timeout 1200;<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""> }<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">The server behind 127.0.0.1:4431 is HAProxy that distributes requests to a number of backend instances.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">All content is served from those instances and nginx does not have access to content from anywhere else.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">Once in a blue moon HAProxy does not have any available server to send a request to, and it generates an internal 503 “Service unavailable” page.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">When the request method is a POST nginx transforms this to a 405 “not allowed”, which is - as far as I can understand from a number of posts found googling -
is to be expected when POSTing to a static resource.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">An individual backend instance can also return a 503 error if it encounters a problem servicing a request.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">That 503 response is sent back to HAProxy, which parses it along to nginx, which returns the 503 to the client (and it’s NOT converted into a 405!), so I know
that nginx doesn’t translate all 503s to 405s if it’s generated by a backend instance even if the request is POSTed.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">This leads me to think that somehow HAProxy does not provide the correct headers in the 503 errorpage to make nginx assume the response from HAProxy isn’t dynamic.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">The internally created 503 page that HAProxy creates is this (since it’s sent more or less “as is” on the TCP socket it contains HTTP lingo - see
<a href="https://cbonte.github.io/haproxy-dconv/1.5/configuration.html#4-errorfile">
https://cbonte.github.io/haproxy-dconv/1.5/configuration.html#4-errorfile</a> for details if questions arrise):<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">---<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">HTTP/1.0 503 Service Unavailable<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">Cache-Control: no-cache<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">Connection: close<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">Content-Type: text/html<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><html><body><h1>503 Service Unavailable</h1><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">No server is available to handle this request.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""></body></html><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">---<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">What headers do I need to have HAProxy add in order for nginx not to turn the 503 into a 405 and see the request (or at least the response) was to/from dynamic
content?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">$ nginx -V<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">nginx version: nginx/1.8.0<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">built by gcc 4.8.5 20150623 (Red Hat 4.8.5-4) (GCC)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">built with OpenSSL 1.0.1e-fips 11 Feb 2013<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">TLS SNI support enabled<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif"">configure arguments: --prefix=/usr/local --conf-path=/etc/nginx/nginx.conf --pid-path=/var/run/nginx.pid --lock-path=/var/lock/nginx.lock --http-client-body-temp-path=/var/tmp/nginx/client_body_temp
--http-proxy-temp-path=/var/tmp/nginx/proxy_temp --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --user=nginx --group=nginx --with-http_realip_module --with-http_ssl_module --with-http_stub_status_module --without-http_fastcgi_module
--without-http_uwsgi_module --without-http_scgi_module --without-http_ssi_module<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:9.0pt;font-family:"Verdana","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:8.0pt;font-family:"Verdana","sans-serif";mso-fareast-language:DA">Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><b><span lang="EN-GB" style="font-size:8.0pt;font-family:"Verdana","sans-serif";color:#333333;mso-fareast-language:DA">Jens Dueholm Christensen </span></b><span style="font-size:12.0pt;font-family:"Verdana","sans-serif";mso-fareast-language:DA"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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