How do I delete the file of user avatar?

This is the goal that I have no idea how to achieve. As an iOS reverse engineer, my idea is that if I know in the source code how/where the server sends this image, I can track back and see where the server loads this image locally. But I read Ruby like reading seudo code, so locating where the server sends this image becomes a great great task for me :sob: That should be a lot easier for a person who’re familiar with the source code though

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In discourse/upload.rb at master · discourse/discourse · GitHub

I saw the table uploads which stored all the uploads of a user. For user Baal998 whose user ID is 1637, I then run SELECT * FROM uploads WHERE user_id = '1637'; and the result is

  id  | user_id | original_filename | filesize | width | height |                                     url                                     |         created_at         |         updated_at         |                   sha1                   | origin | retain_hours | extension | thumbnail_width | thumbnail_height | etag | secure | access_control_post_id | original_sha1 | animated | verified | verification_status 
------+---------+-------------------+----------+-------+--------+-----------------------------------------------------------------------------+----------------------------+----------------------------+------------------------------------------+--------+--------------+-----------+-----------------+------------------+------+--------+------------------------+---------------+----------+----------+---------------------
 2210 |    1637 | 2.pic.jpg         |    60610 |       |        | /uploads/default/original/2X/c/cb2188eaeecc3a648f021fa00da4734bd60ca183.jpg | 2016-08-08 09:37:13.937306 | 2018-01-05 02:38:49.498264 | cb2188eaeecc3a648f021fa00da4734bd60ca183 |        |              | jpg       |                 |                  |      | f      |                        |               |          |          |                   1
(1 row)

Which is the same to running Upload.find(user_avatar.custom_upload_id).url with rails.

My guess is that after the user uploaded avatar, discourse will do something to the original avatar file and store the optimized files in somewhere else?

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In table optimized_images this row seemed suspicious

  id   |                   sha1                   | extension | width | height | upload_id |                                          url                                           | filesize | etag | version |         created_at         |         updated_at         
-------+------------------------------------------+-----------+-------+--------+-----------+----------------------------------------------------------------------------------------+----------+------+---------+----------------------------+----------------------------
 49538 | e6dc9b0d6c18f2a4c3c0d2027534d01cfc89c84e | .jpg      |   135 |    135 |      2210 | /uploads/default/optimized/2X/c/cb2188eaeecc3a648f021fa00da4734bd60ca183_2_135x135.jpg |    10968 |      |       2 | 2016-08-08 09:37:13.937306 | 2016-08-08 09:37:13.937306
(1 row)

The sha1 and filesize matches https://iosre.com/user_avatar/iosre.com/baal998/135/2210_2.png , but on server this file doesn’t exist.

root@iosre:/var/discourse/shared/standalone# ls /uploads/default/optimized/2X/c/cb2188eaeecc3a648f021fa00da4734bd60ca183_2_135x135.jpg
ls: cannot access /uploads/default/optimized/2X/c/cb2188eaeecc3a648f021fa00da4734bd60ca183_2_135x135.jpg: No such file or directory

No idea what was wrong.

Problem solved:

Someone from my forum told me that this avatar image might be stored in nginx cache under proxy_cache_path, which was usually /var/nginx/cache, but I couldn’t find either proxy_cache_path or /var/nginx/cache.

I was inspired by him that I entered the discourse app via launcher enter app and then found nginx cache:

root@iosre:/var/discourse/shared# /var/discourse/launcher enter app
WARNING: Docker version 17.05.0-ce deprecated, recommend upgrade to 17.06.2 or newer.
root@iosre-app:/var/www/discourse# cd /var/nginx/cache
root@iosre-app:/var/nginx/cache# ls
0  1  2  3  4  5  6  7	8  9  a  b  c  d  e  f
root@iosre-app:/var/nginx/cache# 

And deleted all the caches:

root@iosre-app:/var/nginx/cache# ls
root@iosre-app:/var/nginx/cache# 

The image was gone.

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