Here is my Caddyfile:

aruiplex.com {
        encode gzip
        file_server /files/* {
                root /files
                browse
        }
        reverse_proxy /api/* localhost:7022
        file_server {
                root /srv
        }
}

Here is my plan:

1. When request URL is aruiplex.com, Caddy can show me the index.html in /srv directory.

2. When request URL is aruiplex.com/files, Caddy can show me the file list in the /files directory in docker container.

3. When request URL is aruiplex.com/api, Caddy can pass this request to localhost:7022.

But when I request aruiplex.com/files file server is not working, it gives me a 404. And I have check this directory in docker container, there have some files.

Here is my file tree at / in docker container:

/
    /home
    /etc
    /...
    /files
        /aaa.txt
        /bbb.txt
    /srv
        /index.html

Version: Caddy 2.4.6 in Docker.

P.S.: If you see the post on the caddy.community, it also me.

Deploying and serving different contents of the project

Serve the website, API, and content of the folder with the handle and handle_path directives to serve

Here is the sample project I created for the same usercase

├── Caddyfile
├── app
│   └── index.html
├── docker-compose.yml
├── files
│   ├── bye.txt
│   └── hello.txt
└── logs
    └── access.log

Caddyfile, replace 8080 with your domain example.com

:8080 {
    handle /api* {
        reverse_proxy localhost:7022
    }
    handle_path /files* {
        root * /files
        file_server browse
    }
    handle {
        root * /srv
        file_server browse
    }
}

:7022 {
    respond "Hey! I AM API" 
}

docker-compose.yml

version: "3"
services:
  caddy:
    restart: always
    image: caddy:2.4.6
    container_name: caddy
    ports:
      - 8080:8080 # Configure Caddyfile with port opened
    volumes:
      - ./Caddyfile:/etc/caddy/Caddyfile
      - caddy_data:/data
      - caddy_config:/config
      - ./app:/srv
      - ./files:/files
      - ./logs:/var/log
volumes:
  caddy_data: 
  caddy_config: