Nginx: enable/disable caching depending on HTTP method

Question

I asked this question on serverfault, but nobody answered. Hope, stackoverflow people know Nginx better :)

I want to handle all [GET] requests to /api from cache and handle all other requests as in last location block (without cache). All the requests to /api with methods PUT, POST, DELETE also have not to use cache.

I saw the similar question here, but still can not understand how to use it in my case.

Thanks in advance.

My config:

location / {
    root /var/www/project/web;
    # try to serve file directly, fallback to app.php
    try_files $uri /app.php$is_args$args;
}


location ~ ^/api {
    root /var/www/project/web/app.php;
    fastcgi_send_timeout 600s;
    fastcgi_read_timeout 600s;
    fastcgi_pass unix:/var/run/php5-fpm.sock;
    fastcgi_split_path_info ^(.+\.php)(/?.*)$;
    include fastcgi_params;
    fastcgi_cache fcgi;
    fastcgi_cache_valid 200 5m;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param HTTPS off;

}

location ~ ^/(app|app_dev|config)\.php(/|$) {
    root /var/www/project/web;
    fastcgi_send_timeout 600s;
    fastcgi_read_timeout 600s;
    fastcgi_pass unix:/var/run/php5-fpm.sock;
    fastcgi_split_path_info ^(.+\.php)(/?.*)$;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param HTTPS off;
}

Answer 1

It's pretty simple thankfully. Nginx's modules (proxy, fastcgi, uwsgi etc) all have the ability to inform a request not to use the cache.

location ~ ^/api {
    root /var/www/project/web/app.php;
    fastcgi_send_timeout 600s;
    fastcgi_read_timeout 600s;
    fastcgi_pass unix:/var/run/php5-fpm.sock;
    fastcgi_split_path_info ^(.+\.php)(/?.*)$;
    include fastcgi_params;

    # Don't cache anything by default
    set $no_cache 1;

    # Cache GET requests
    if ($request_method = GET)
    {
        set $no_cache 0;
    }

    fastcgi_cache_bypass $no_cache;
    fastcgi_no_cache $no_cache;

    fastcgi_cache fcgi;
    fastcgi_cache_valid 200 5m;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param HTTPS off;
}

As per Richard Smith's suggestion, a more elegant solution using the maps directive is below:

map $request_method $api_cache_bypass {
    default       1;
    GET           0;
}

location ~ ^/api {
    root /var/www/project/web/app.php;
    fastcgi_send_timeout 600s;
    fastcgi_read_timeout 600s;
    fastcgi_pass unix:/var/run/php5-fpm.sock;
    fastcgi_split_path_info ^(.+\.php)(/?.*)$;
    include fastcgi_params;

    fastcgi_cache_bypass $api_cache_bypass;
    fastcgi_no_cache $api_cache_bypass;

    fastcgi_cache fcgi;
    fastcgi_cache_valid 200 5m;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param HTTPS off;
}

The additions to the location are essentially telling Nginx to use or ignore the cache depending on the verb. It sets $no_cache to 1, which will bypass the cache for all requests, except where the method is GET when it is set to 0 which instructs it to use the cache (if available).