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Diffstat (limited to 'doc/builders/packages/nginx.xml')
| -rw-r--r-- | doc/builders/packages/nginx.xml | 25 |
1 files changed, 0 insertions, 25 deletions
diff --git a/doc/builders/packages/nginx.xml b/doc/builders/packages/nginx.xml deleted file mode 100644 index 65854ba0236..00000000000 --- a/doc/builders/packages/nginx.xml +++ /dev/null @@ -1,25 +0,0 @@ -<section xmlns="http://docbook.org/ns/docbook" - xmlns:xlink="http://www.w3.org/1999/xlink" - xml:id="sec-nginx"> - <title>Nginx</title> - - <para> - <link xlink:href="https://nginx.org/">Nginx</link> is a reverse proxy and lightweight webserver. - </para> - - <section xml:id="sec-nginx-etag"> - <title>ETags on static files served from the Nix store</title> - - <para> - HTTP has a couple different mechanisms for caching to prevent clients from having to download the same content repeatedly if a resource has not changed since the last time it was requested. When nginx is used as a server for static files, it implements the caching mechanism based on the <link xlink:href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Last-Modified"><literal>Last-Modified</literal></link> response header automatically; unfortunately, it works by using filesystem timestamps to determine the value of the <literal>Last-Modified</literal> header. This doesn't give the desired behavior when the file is in the Nix store, because all file timestamps are set to 0 (for reasons related to build reproducibility). - </para> - - <para> - Fortunately, HTTP supports an alternative (and more effective) caching mechanism: the <link xlink:href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag"><literal>ETag</literal></link> response header. The value of the <literal>ETag</literal> header specifies some identifier for the particular content that the server is sending (e.g. a hash). When a client makes a second request for the same resource, it sends that value back in an <literal>If-None-Match</literal> header. If the ETag value is unchanged, then the server does not need to resend the content. - </para> - - <para> - As of NixOS 19.09, the nginx package in Nixpkgs is patched such that when nginx serves a file out of <filename>/nix/store</filename>, the hash in the store path is used as the <literal>ETag</literal> header in the HTTP response, thus providing proper caching functionality. This happens automatically; you do not need to do modify any configuration to get this behavior. - </para> - </section> -</section> |