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hyperknot
Asked: 2024-09-11 01:26:54 +0800 CST

nginx try_files always falling to proxy

  • 772

I have the following nginx config:

server {
    location ~ ^/(\d+)/(\d+)/(\d+)\.png$ {
        alias /mount/cache/c/$1/$2/$3.png;
        try_files $uri @proxy;
        add_header x-source file;
    }

    location @proxy {
        proxy_pass http://127.0.0.1:28000;
        add_header x-source proxy;
    }
}

What I'm trying to achieve is to try to load the files from disk, and if they are not found only then ask the upstream for it.

My problem is that try_files doesn't seem to work, it always requests @proxy (x-source header is always proxy). If I comment out try_files then it loads the files from the disk correctly, but then the proxy part doesn't work.

nginx

2 Answers

  1. Best Answer

    In this example you don't need to use alias at all.

    server {
    location ~ ^/(\d+)/(\d+)/(\d+)\.png$ {
        root /mount/cache/c;
        try_files $uri @proxy;
        add_header x-source file;
    }
    ...
}

    If you need an alias, then don't use try_files. Use, for example, error_page.

    server {
    location ~ ^/(\d+)/(\d+)/(\d+)\.png$ {
        alias /mount/cache/c/$1/$2/$3.png;
        add_header x-source file;

        error_page 404 = @proxy;
    }
    ...
}
    • 1

  2. The issue becomes from your alias directive.

    Suppose a resource http://example.com/1/2/3.png is requested.

    The alias directive means that nginx will look up a file at /mount/cache/c/1/2/3.png/1/2/3/.png. This is because alias sets the base path where files are located, and then the $uri is appended to the get the final resource.

    This should work with this config:

    server {
    location ~ ^/(\d+)/(\d+)/(\d+)\.png$ {
        alias /mount/cache/c;
        try_files $uri @proxy;
        add_header x-source file;
    }

    location @proxy {
        proxy_pass http://127.0.0.1:28000;
        add_header x-source proxy;
    }
}

    provided that your files are located in /mount/cache/c directory.

    • 0