NGINX getting an application in a subfolder to work with redirects

Question

I've installed Mautic in a subfolder like: example.com/m
Most of Mautic is working fine with my configuration (admin panel, using Mautic etc.) but for some redirects in my subfolder, I get a 404:

example.com/m 200
example.com/m/form/9 200
example.com/m/form/generate.js?id=9 404

(/form doesn't exist - it should be redirected/generated by Mautic dynamically)

All files on the file system belong to www-data.

My nginx conf for the host:

server {
    server_name www.example.com;
    rewrite_log on;

    root /var/www/example.com/www.example.com;
    index index.php index.html index.htm;

    access_log /var/log/nginx/example.com_access.log;
    error_log /var/log/nginx/example.com_error.log notice;

    #######################################
    ##  Start Mautic Specific config #####
    #######################################

    location /m {
        # Working despite forms:
        try_files $uri $uri/ /m/?q=$uri&$args;
    }

    #######################################
    ##  End Mautic Specific config #####
    #######################################

    location / {
        try_files $uri $uri/ /index.php$is_args$args;
    }

    location ~ \.php$ {
        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/var/run/php/php7.3-fpm.sock;
    }

    # A long browser cache lifetime can speed up repeat visits to your page
    location ~* \.(jpg|jpeg|gif|png|webp|svg|woff|woff2|ttf|css|js|ico|xml)$ {
       access_log        off;
       log_not_found     off;
       expires           360d;
    }

    # disable access to hidden files
    location ~ /\.ht {
      access_log off;
      log_not_found off;
      deny all;
    }

    listen [::]:443 ssl; # managed by Certbot
    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/stats.example.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/stats.example.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}

server {
    listen 443 ssl;
    server_name example.com;
    listen [::]:443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/stats.example.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/stats.example.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
    return 301 https://www.example.com$request_uri;

}

server {
    if ($host = example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    if ($host = www.example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    server_name example.com www.example.com;
    listen 80;
    listen [::]:80;
    return 301 https://$host$request_uri;
    #return 404; # managed by Certbot

}

What am I doing wrong?

Answer 1

You want URIs that begin with /m to be handled by the location /m block.

However, regular expression locations take precedence, so the URI /m/form/generate.js is actually being handled by another location that matches all URIs that end with .js. See this document.

There is the ^~ operator which forces the prefix location to take precedence, but that will not work in your case, as the application is PHP, and you need URIs that end with .php to be handled by the location ~ \.php$ block.

So instead, I suggest you nest the location causing the problem within the location / block.

For example:

location /m {
    try_files $uri $uri/ /m/?q=$uri&$args;
}

location / {
    try_files $uri $uri/ /index.php$is_args$args;

    location ~* \.(jpg|jpeg|gif|png|webp|svg|woff|woff2|ttf|css|js|ico|xml)$ {
        access_log        off;
        log_not_found     off;
        expires           360d;
    }
}

location ~ \.php$ {
    ...
}

location ~ /\.ht {
    ...
}