How to redirect user if direct access image files by browser? [nginx]

TravelWhere

5/16/23, 2:59 AM

How do I redirect if a user tries to direct access image files in browser only? I want to keep the ability to embed images with <img src="...">. How to redirect from

https://img.example.com/c/600x1200_90_webp/img-master/img/2022/01/03/08/04/54/95259215_p0_master1200.jpg

https://example.com/detail?id=95259215

This is my nginx conf

location ~ "^/c/600x1200_90_webp/img-master/img/\d+/\d+/\d+/\d+/\d+/\d+/(?<filename>.+\.(jpg|png|webp))$" {
    return 301 https://example.com/detail?id=$filename;
}

Code isn't working cause it's going to https://example.com/detail?id=95259215_p0_master1200.jpg but I need it to trim the string after the last digit of the filename so in this case trim off _p0_master1200.jpg. I also don't know how to make it if user is accessing it through browser.

0 + 0

rewrite

nginx

redirect

Score:0

Server

Tero Kilkanen

5/16/23, 9:31 AM

Your regular expression (?<filename>.+\.(jpg|png|webp))$ captures the whole filename to the filename variable. To exctract only part before _ to variable, use the following instead:

(?<filename>[0-9]+).+(?:jpg|png|webp)$

This one only matches numbers for the filename variable (I would call it image_id to be more descriptive). https://regexr.com is a good tool for working with regular expressions.

For limiting display only to browsers, you need to use nginx http referer module.

These two combined, the configuration would look like:

location ~ "^/c/600x1200_90_webp/img-master/img/\d+/\d+/\d+/\d+/\d+/\d+/(?<filename>[0-9]+).+(?:jpg|png|webp)$" {
    valid_referers server_names;
    if ($invalid_referer = "0") {
        return 301 https://example.com/detail?id=$filename;
    }
}

nginx will check the HTTP Referer value. If it contains the name specified in server_name field, it will send the redirect. The referer field is set by browser when it loads resources for a web page.

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Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: How to redirect user if direct access image files by browser? [nginx]

TH: จะเปลี่ยนเส้นทางผู้ใช้ได้อย่างไรหากเข้าถึงไฟล์ภาพโดยตรงโดยเบราว์เซอร์ [งินซ์]

RO: Cum se redirecționează utilizatorul dacă fișierele imagine cu acces direct prin browser? [nginx]

RU: Как перенаправить пользователя при прямом доступе к файлам изображений через браузер? [nginx]

VI: Làm cách nào để chuyển hướng người dùng nếu truy cập trực tiếp tệp hình ảnh bằng trình duyệt? [nginx]

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