Managing User Containers from the Terminal

In OpenPanel, each user has their own Docker context running in rootless mode. If you are familiar with Docker, you can manage a user’s files and services directly from the terminal.

SSH access as the root user on the server is required to switch between Docker contexts.

Compose Setup​

Each user’s environment is based on:

• docker-compose.yml – defines services, networks, and volumes.
• .env – defines CPU/memory limits, Docker image tags, and custom ports.

⚠️ Always edit these files via the OpenAdmin interface. The interface validates your changes. Editing directly from the terminal bypasses validation and can break services. Make a backup before any modifications.

• Volume Management in OpenPanel
• Network Isolation in OpenPanel

File Structure​

Each user’s home directory is located at:

/home/USERNAME/

It contains configuration files and user data. Example structure:

├── .env                 # Environment variables: versions, ports, CPU/memory limits
├── backup.env           # Backup configuration
├── crons.ini            # Cron jobs
├── custom.cnf           # MySQL configuration
├── default.vcl          # Varnish cache configuration
├── docker-compose.yml   # Service definitions
├── docker-data          # Docker storage
│   ├── containerd       # Container runtime data
│   ├── containers       # Individual container data
│   ├── image            # Docker images
│   ├── network          # Docker networks
│   ├── overlay2         # Overlay filesystem storage
│   ├── plugins          # Docker plugins
│   └── volumes          # Persistent data volumes
│       ├── <USERNAME>_html_data   # Website files (/var/www/html/)
│       └── <USERNAME>_mysql_data  # MySQL database files (/var/lib/mysql/)
├── httpd.conf           # Apache configuration
├── my.cnf               # MySQL root credentials for service commands
├── nginx.conf           # NGINX configuration
├── openlitespeed.conf   # OpenLiteSpeed configuration
├── openresty.conf       # OpenResty configuration
├── php.ini/             # PHP configuration files
├── pma.php              # phpMyAdmin entry point
└── sockets              # Sockets (MySQL, Redis, PostgreSQL, etc.)

• Website files are stored in the Docker volume USERNAME_html_data and physically located at:

/home/USERNAME/docker_data/volumes/USERNAME_html_data/_data/

• File ownership should match the OpenPanel user ID. Check with:

id -u USERNAME

• Docker runs in rootless mode, mapping the user UID to root inside containers. This avoids permission issues while giving the user root-level permissions in their services.

• Disk quotas are enforced using the quota tool. To check disk and inodes usage for user:

quota -u USERNAME

Managing Services​

Services are defined in /home/USERNAME/docker-compose.yml. You can extend this file with custom services, but to maintain compatibility with the OpenPanel UI, follow the guidelines.

Use the user’s Docker context to manage their services. Examples:

• List running services:

docker --context=USERNAME ps -a

• Stop a service:

docker --context=USERNAME stop mysql

• Restart a service:

cd /home/USERNAME && \
docker --context=USERNAME compose down mysql && \
docker --context=USERNAME compose up -d mysql

• Exec into a service:

docker --context=USERNAME exec -it mysql bash

• View resource usage:

docker --context=USERNAME stats --no-stream

Domains​

Domain configuration files are stored in:

• Caddy configuration:

/etc/openpanel/caddy/domains/<DOMAIN>.conf

Each domain has its own Caddyfile. Caddy handles SSL certificates and acts as a reverse proxy to the user’s web server. For more information, see: How Web Traffic Flows with User Containers

• BIND9 zone file:

/etc/bind/zones/<DOMAIN>.db

Contains the DNS records for the domain.

Backups​

OpenPanel uses offen/docker-volume-backup for backups. Configuration is stored in /home/{CONTEXT}/backup.env.

• Administrators can schedule automatic backups for users.
• Users can also enable and manage their own backups if permitted.
• Only Docker volumes are backed up, which include the actual user data (website files and databases).

For detailed instructions, see: Configuring OpenPanel Backups

Crons​

OpenPanel uses mcuadros/ofelia for cron obs. Configuration is stored in /home/{CONTEXT}/crons.ini.

Ports​

Ports are defined in the user’s .env file:

root@stefan:/# grep _PORT /home/stefan/.env 
HTTP_PORT="127.0.0.1:32780:80"
HTTPS_PORT="127.0.0.1:32781:443"
PROXY_HTTP_PORT="127.0.0.1:32782:80" 
MYSQL_PORT="127.0.0.1:32777:3306"
PMA_PORT="32779:80"
POSTGRES_PORT="0:5432"
PGADMIN_PORT="0:80"

• Ports are generated during user creation but can be modified by the administrator. After changes, run compose down && compose up for the changes to take effect.
• ⚠️ Docker rootless mode prevents the use of ports under 1024.
• Services should not expose ports externally unless remote access is required (e.g., phpMyAdmin, remote MySQL, or pgAdmin).