Wordpress: Subdirectory problem (wp-admin redirect)

[forcemagic]

I have looked through several related issues, but could not find a solution. It only happens when I'm at /wp-admin.

I get a sort of 'redirect' when I access wp-admin. Seems like a pushState. Found this thing:

<link id="wp-admin-canonical" rel="canonical" href="https://example.com/wp-admin/">

...which is incorrect, because I want it to be in a subdirectory. Where does this tag get its information from? I have set WP_HOME and WP_SITEURL variables (see below).

docker-compose.yml:

version: '3.3'

services:
   db:
     image: mysql:5.7
     volumes:
       - db_data:/var/lib/mysql
     restart: always
     environment:
       MYSQL_ROOT_PASSWORD: somewordpress
       MYSQL_DATABASE: wordpress
       MYSQL_USER: wordpress
       MYSQL_PASSWORD: wordpress

   wordpress:
     depends_on:
       - db
     image: wordpress:latest
     ports:
       - "8010:80"
     restart: always
     environment:
       WORDPRESS_CONFIG_EXTRA: |
         define('WP_HOME', 'https://example.com/subdir');
         define('WP_SITEURL', 'https://example.com/subdir');
         define('DOMAIN_CURRENT_SITE', 'example.com');
         define('PATH_CURRENT_SITE', '/subdir/');
       WORDPRESS_DB_HOST: db:3306
       WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: wordpress
       WORDPRESS_DB_NAME: wordpress
volumes:
    db_data: {}

EDIT: Because I'm using nginx, let me just post my config for that too...

        location /subdir/ {
                proxy_pass http://localhost:8010/;
                proxy_redirect off;

                proxy_set_header Host $host;
                proxy_set_header X-Forwarded-Proto $scheme;
                proxy_set_header X-Real-Ip $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }

[tianon]

I recommend you ditch WORDPRESS_CONFIG_EXTRA entirely and instead simply use workdir: /var/www/html/subdir (see https://github.com/docker-library/wordpress/issues/221#issuecomment-356454850).

[forcemagic]

The directive is working_dir, but it works perfectly now! Thank you for your help!