Nginx – How to Use Different try_files Based on Query Parameter

nginx

location / {
    try_files "/wp-content/cache/all/${uri}index.html" $uri $uri/ /index.php?q=$uri&$args;
}

But if there is a visual editor used, I don't want to use the cache. So it should be

location / {
    if ($args ~ visual-editor){
        try_files $uri $uri/ /index.php?q=$uri&$args;
    }
    try_files "/wp-content/cache/all/${uri}index.html" $uri $uri/ /index.php?q=$uri&$args;
}

Except it doesn't work because nginx is restrictive and weird to someone who mostly did apache configs.

I tried named locations, I tried a sub location to make it happy about using try_files, I don't want a rewrite, using the error code hack with named locations will cause query parameters to be removed which can't happen.

The idea is simple, don't load the cached html file if there's some exclusion I define. But nothing seems to work and the internet gives answers that never answer my question so asking here.

Best Answer

You cannot put try_files into an if block, but you can set a variable in the if block and use that to invalidate the first term of the try_files statement.

For example:

server {
    ...
    set $cache /wp-content/cache/all;
    if ($args ~ visual-editor) { set $cache /nonexistent; }

    location / {
        try_files $cache${uri}index.html $uri $uri/ /index.php?q=$uri&$args;
    }
    ...
}

See this caution on the use of if.

Correct way in new versions of nginx

Turn out my first answer to this question was correct at certain time, but it turned into another pitfall - to stay up to date please check Taxing rewrite pitfalls

I have been corrected by many SE users, so the credit goes to them, but more importantly, here is the correct code:

server {
       listen         80;
       server_name    my.domain.com;
       return         301 https://$server_name$request_uri;
}

server {
       listen         443 ssl;
       server_name    my.domain.com;
       # add Strict-Transport-Security to prevent man in the middle attacks
       add_header Strict-Transport-Security "max-age=31536000" always; 

       [....]
}

nginx try_files – How Does try_files Work in nginx?

try_files tries the literal path you specify in relation to the defined root directive and sets the internal file pointer. If you use for instance try_files /app/cache/ $uri @fallback; with index index.php index.html; then it will test the paths in this order:

$document_root/app/cache/index.php
$document_root/app/cache/index.html
$document_root$uri

before finally internally redirecting to the @fallback named location. You can also use a file or a status code (=404) as your last parameter but if using a file it must exist.

You should note that try_files itself will not issue an internal redirect for anything but the last parameter. Meaning you cannot do the following: try_files $uri /cache.php @fallback; as that will cause nginx to set the internal file pointer to $document_root/cache.php and serve it, but since no internal redirect takes place the locations aren't re-evaluated and as such it will be served as plain text. (The reason it works with PHP files as the index is that the index directive will issue an internal redirect)

Best Answer

Related Solutions

NGINX Redirect – How to Rewrite All HTTP Requests to HTTPS While Maintaining Sub-Domain

Correct way in new versions of nginx

nginx try_files – How Does try_files Work in nginx?

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