Documentation example(s) for reverse-proxy with docker-compose

Is your feature request related to a problem? Please describe

I am eager to try castopod on my VPS to explore hosting a new podcast. I am fairly well-versed in Docker and have created a few multi-image projects via docker-compose and utilizing projects like linuxserver.io's fleet of images. I am trying to replicate their setup for using swag like in my other containers, but I keep getting 502 bad gateway errors.

Describe the solution you'd like

The documentation page for example Docker usage mentions the following regarding reverse-proxies:

Setup a reverse proxy for TLS (SSL/HTTPS)

TLS is mandatory for ActivityPub to work. This job can easily be handled by a reverse proxy, for example with Caddy

Would it be possible to add an example that uses caddy, swag, or another easy-to-use reverse proxy image within a docker-compose context?

Additional context

Below are my current versions of the docker-compose.yml and customized proxy configuration file used by swag (anonymized IP address and salt):

docker-compose

version: "3.7"

services:
  app:
    image: castopod/app:latest
    container_name: "castopod-app"
    volumes:
      - /home/eric/docker_configs/castopod_configs/castopod-media:/opt/castopod/public/media
    environment:
      - MYSQL_DATABASE=castopod
      - MYSQL_USER=castopod
      - MYSQL_PASSWORD=mypass123**
      - CP_BASEURL=http://castopod.mydomain.com
      - CP_ANALYTICS_SALT=mysalt
      - CP_CACHE_HANDLER=redis
      - CP_REDIS_HOST=redis
      - PGID=1000
      - PUID=1000
   #networks:
   #   - castopod-app
   #   - castopod-db
    restart: unless-stopped

  castopod:
    image: castopod/web-server:latest
    container_name: "castopod"
    volumes:
      - /home/eric/docker_configs/castopod_configs/castopod-media:/var/www/html/media
    #networks:
    #  - castopod-app
    ports:
      - 8080:8080
    environment:
      - PGID=1000
      - PUID=1000
    restart: unless-stopped

  mariadb:
    image: mariadb:10.5
    container_name: "castopod-mariadb"
    #networks:
    #  - castopod-db
    volumes:
      - /home/eric/docker_configs/castopod_configs/castopod-db:/var/lib/mysql
    environment:
      - MYSQL_ROOT_PASSWORD=mypass123**
      - MYSQL_DATABASE=castopod
      - MYSQL_USER=castopod
      - MYSQL_PASSWORD=mypass123**
      - PGID=1000
      - PUID=1000
    restart: unless-stopped

  redis:
    image: redis:7.0-alpine
    container_name: "castopod-redis"
    volumes:
      - /home/eric/docker_configs/castopod_configs/castopod-cache:/data
    #networks:
    #  - castopod-app
    environment:
      - PGID=1000
      - PUID=1000

  # this container is optional
  # add this if you want to use the videoclips feature
  video-clipper:
    image: castopod/video-clipper:latest
    container_name: "castopod-video-clipper"
    volumes:
      - /home/eric/docker_configs/castopod_configs/castopod-media:/opt/castopod/public/media
    environment:
      - MYSQL_DATABASE=castopod
      - MYSQL_USER=castopod
      - MYSQL_PASSWORD=mypass123**
      - PGID=1000
      - PUID=1000
    #networks:
    #  - castopod-db
    restart: unless-stopped
  
  swag:
    image: ghcr.io/linuxserver/swag
    container_name: castopod-swag
    cap_add:
      - NET_ADMIN
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=America/New_York
      - URL=mydomain.com
      - SUBDOMAINS=castopod
      - VALIDATION=http
      - DNSPLUGIN=cloudflare #optional
      - PROPAGATION= #optional
      - DUCKDNSTOKEN= #optional
      - EMAIL=thercast@gmail.com
      - ONLY_SUBDOMAINS=true #optional
      - EXTRA_DOMAINS= #optional
      - STAGING=false #optional
    volumes:
      - /home/eric/docker_configs/castopod_configs/swag/config:/config
    ports:
      - "443:443"
      - "80:80"
    restart: "unless-stopped"

volumes:
  castopod-media:
  castopod-db:
  castopod-cache:

castopod.subdomain.conf

## Version 2022/09/08
# REMOVE THIS LINE BEFORE SUBMITTING: The structure of the file (all of the existing lines) should be kept as close as possible to this template.
# REMOVE THIS LINE BEFORE SUBMITTING: Look through this file for <tags> and replace them. Review other sample files to see how things are done.
# REMOVE THIS LINE BEFORE SUBMITTING: The comment lines at the top of the file (below this line) should explain any prerequisites for using the proxy such as DNS or app settings.
# make sure that your dns has a cname set for <container_name> and that your <container_name> container is not using a base url

server {
    listen 443 ssl;
    listen [::]:443 ssl;

    #server_name <container_name>.*;
    server_name castopod.*;

    include /config/nginx/ssl.conf;

    client_max_body_size 0;

    location / {
        include /config/nginx/proxy.conf;
        include /config/nginx/resolver.conf;
        #set $upstream_app <container_name>;
        set $upstream_app castopod;
        #set $upstream_port <port_number>;
        set $upstream_port 8080;
        #set $upstream_proto <http or https>;
        set $upstream_proto http;
        proxy_pass $upstream_proto://$upstream_app:$upstream_port;
    }
}