Nextcloud version: 25.0.0
Operating system and version : Docker Image running on Windows' WSL2
Apache or nginx version : Reverse Proxy nginx 1.21.6-1~bullseye → Nextcloud apache2 2.4.54-1~deb11u1
PHP version : 8.1.12
Hi everyone! Thanks for this support forum 
I am running Nextcloud with the docker image and an nginx reverse proxy as explained in this tutorial I found
This setup works fantastic when accessed from outside my lan (through my dyndns wonderfuldns.ddns.net) but I am absolutely unable to access it from inside my lan, ie, https://localhost:443, as it says: 503 Service Temporarily Unavailable
It certainly must be something related to docker-compose.yaml configuration or config.php settings, but I am no expert on docker, so I can’t debug much 
This is my NextCloud’s docker configuration
version: "3.7"
services:
NCDatabase:
image: "mariadb:latest"
volumes:
- "NCMariaDB:/var/lib/mysql"
environment:
- MYSQL_ROOT_PASSWORD
- MYSQL_RANDOM_ROOT_PASSWORD
- MYSQL_DATABASE
- MYSQL_USER
- MYSQL_PASSWORD
restart: "on-failure"
networks: ["common"]
NCFrontend:
image: "nextcloud:latest"
volumes:
- "NCData:/var/www/html"
- "E:\\:/prodDrive"
environment:
- LETSENCRYPT_HOST
- VIRTUAL_HOST
- TRUSTED_PROXIES
- OVERWRITEPROTOCOL
- MYSQL_DATABASE
- MYSQL_USER
- MYSQL_PASSWORD
- MYSQL_HOST
- SMTP_HOST
- SMTP_PORT
- SMTP_NAME
- SMTP_PASSWORD
- MAIL_FROM_ADDRESS
- NEXTCLOUD_TRUSTED_DOMAINS
- NEXTCLOUD_ADMIN_USER
- NEXTCLOUD_ADMIN_PASSWORD
depends_on:
- "NCDatabase"
restart: "on-failure"
networks: ["net", "common"]
volumes:
NCMariaDB:
NCData:
networks:
net:
external: true
common:
internal: true
And this is my reverse proxy configuration. Notice how Nextcloud is not visible on any port, but the reverse proxy has both http and https ports open:
version: "3.3"
services:
NginxProxy:
image: "jwilder/nginx-proxy:latest"
volumes:
- "NPhtml:/usr/share/nginx/html"
- "NPdhparam:/etc/nginx/dhparam"
- "NPvhost:/etc/nginx/vhost.d"
- "NPcerts:/etc/nginx/certs:ro"
- "/var/run/docker.sock:/tmp/docker.sock:ro"
- "./client_max_upload_size.conf:/etc/nginx/conf.d/client_max_upload_size.conf"
labels:
- "com.github.jrcs.letsencrypt_nginx_proxy_companion.nginx_proxy"
restart: "on-failure"
networks: ["net"]
ports:
- "80:80"
- "443:443"
LetsencryptCompanion:
image: "jrcs/letsencrypt-nginx-proxy-companion:latest"
volumes:
- "LCacme:/etc/acme.sh"
- "NPvhost:/etc/nginx/vhost.d"
- "NPcerts:/etc/nginx/certs"
- "NPhtml:/usr/share/nginx/html"
- "/var/run/docker.sock:/var/run/docker.sock:ro"
environment:
- DEFAULT_EMAIL
depends_on: ["NginxProxy"]
restart: "on-failure"
networks: ["net"]
volumes:
NPhtml:
NPdhparam:
NPvhost:
NPcerts:
LCacme:
networks:
net:
external: true
And this is my config.php configuration. Be careful when looking at trusted_proxies number 1. That localhost has been included after the installation of the system with occ. It was a desperate attempt to make this setup work on my localnet (at least on my localhost), but didn’t work:
<?php
$CONFIG = array (
'htaccess.RewriteBase' => '/',
'memcache.local' => '\\OC\\Memcache\\APCu',
'apps_paths' =>
array (
0 =>
array (
'path' => '/var/www/html/apps',
'url' => '/apps',
'writable' => false,
),
1 =>
array (
'path' => '/var/www/html/custom_apps',
'url' => '/custom_apps',
'writable' => true,
),
),
'overwriteprotocol' => 'https',
'trusted_proxies' =>
array (
0 => '172.18.0.0/16',
1 => 'localhost',
),
'instanceid' => 'ocap8kq864m1',
'passwordsalt' => '<password>',
'secret' => '<password>',
'trusted_domains' =>
array (
0 => 'wonderfuldns.ddns.net',
1 => 'localhost',
),
'datadirectory' => '/var/www/html/data',
'dbtype' => 'mysql',
'version' => '25.0.0.18',
'overwrite.cli.url' => 'https://wonderfuldns.ddns.net',
'dbname' => 'NC',
'dbhost' => 'NCDatabase',
'dbport' => '',
'dbtableprefix' => 'oc_',
'mysql.utf8mb4' => true,
'dbuser' => 'nextcloud',
'dbpassword' => '<password>',
'installed' => true,
'maintenance' => false,
'theme' => '',
'loglevel' => 2,
);
#
In case you need to know the values for the env variables, they are these:
MYSQL_ROOT_PASSWORD=<password>
MYSQL_DATABASE=NC
MYSQL_USER=nextcloud
MYSQL_PASSWORD=<password>
MYSQL_HOST=NCDatabase
LETSENCRYPT_HOST=wonderfuldns.ddns.net
VIRTUAL_HOST=wonderfuldns.ddns.net
TRUSTED_PROXIES=172.18.0.0/16
OVERWRITEPROTOCOL=https
NEXTCLOUD_TRUSTED_DOMAINS=wonderfuldns.ddns.net
I am really sorry for not being able to offer much more info about my problem and I am very grateful for your help. Thank you very much