Obsidean_VM/01-Documentation/Dockers/Docker Basics - Essential Commands and Usage Guide.md

***


#### Ports:
---
```bash

-p {outside}:{inside}


```


```bash
NAMES         PORTS
portainer     0.0.0.0:8000->8000/tcp, :::8000->8000/tcp, 0.0.0.0:9000->9000/tcp, :::9000->9000/tcp, 9443/tcp
sonarr        0.0.0.0:8989->8989/tcp, :::8989->8989/tcp
radarr        0.0.0.0:7878->7878/tcp, :::7878->7878/tcp
jackett       0.0.0.0:9117->9117/tcp, :::9117->9117/tcp
prowlarr      0.0.0.0:9696->9696/tcp, :::9696->9696/tcp
uglyfeed      0.0.0.0:8001->8001/tcp, :::8001->8001/tcp, 0.0.0.0:8501->8501/tcp, :::8501->8501/tcp
bazarr        0.0.0.0:6767->6767/tcp, :::6767->6767/tcp
Gitea-DB      3306/tcp, 33060/tcp
plantuml      0.0.0.0:8881->8080/tcp, :::8881->8080/tcp
lidarr        0.0.0.0:8686->8686/tcp, :::8686->8686/tcp
jellyfin
unmanic       0.0.0.0:8888->8888/tcp, :::8888->8888/tcp
whisper       0.0.0.0:9005->9000/tcp, :::9005->9000/tcp
qbittorrent   0.0.0.0:6881->6881/tcp, :::6881->6881/tcp, 0.0.0.0:8080->8080/tcp, 0.0.0.0:6881->6881/udp, :::8080->8080/tcp, :::6881->6881/udp
searx-searx   8080/tcp
gitea         0.0.0.0:2222->22/tcp, :::2222->22/tcp, 0.0.0.0:3052->3000/tcp, :::3052->3000/tcp
watchtower    8080/tcp

```


### Managing Ports in Docker on Synology

When setting up multiple containers, it's important to avoid port conflicts. Here are several methods to check which ports are already in use:

#### Using Docker Commands

bash

```bash
# List all running containers with their port mappings
docker ps --format "{{.Names}}: {{.Ports}}"

# For a more detailed view of all port bindings
docker container ls --format "table {{.Names}}\t{{.Ports}}"

# Get only the host ports that are currently mapped
docker ps -q | xargs -n 1 docker port | grep -o '[0-9]*:[0-9]*' | cut -d: -f1 | sort -nu
```

#### Using Synology Tools

1. **Synology Docker UI**:
    - Open Docker package in DSM
    - Go to "Container" tab
    - View the "Port Settings" column
2. **Using Portainer**:
    - Open Portainer web interface
    - Go to "Containers" section
    - View the "Published Ports" column
3. **From Synology DSM**:
    - Go to Control Panel → Network → Network Interface
    - Click "Network Port Status" to see all used ports

#### Check System-Wide Port Usage

To see all ports in use on the system (not just Docker):

bash

```bash
# Requires SSH access with admin privileges
sudo netstat -tulpn | grep LISTEN
```

#### Creating a Port Inventory Script

You can create a simple script in Task Scheduler to maintain a port inventory:

bash

```bash
#!/bin/bash
# Save as port_inventory.sh in Task Scheduler

echo "Docker Port Inventory - $(date)" > /volume1/docker/port_inventory.txt
echo "----------------------------------------" >> /volume1/docker/port_inventory.txt
docker ps --format "{{.Names}}: {{.Ports}}" >> /volume1/docker/port_inventory.txt
echo "" >> /volume1/docker/port_inventory.txt
echo "System-wide ports:" >> /volume1/docker/port_inventory.txt
netstat -tulpn | grep LISTEN >> /volume1/docker/port_inventory.txt
```

Run this script periodically or before creating new containers to maintain an up-to-date list of used ports, helping you avoid conflicts when configuring new containers.

## Docker on Synology NAS

Synology NAS provides a Docker package that offers both GUI and command-line interfaces for managing containers. However, for more complex container configurations, using custom scripts is often more efficient.

### Best Practices for Synology Docker Deployments

1. **Standard Directory Structure**:
    
    - Use `/volume1/docker/[container_name]/` for container configurations
    - This organization makes backups and migrations easier
2. **User Permissions**:
    
    - Synology has a predefined `docker` user which should be used for container directories
    - Typical PUID/PGID values in Synology: PUID=1033 (docker user), PGID=100 (users group)
3. **Script-Based Management**:
    
    - Create container deployment scripts in the Synology Task Scheduler
    - Run scripts as root to ensure proper permissions
    - For modifications, either:
        - Update the script and recreate the container
        - Make minor adjustments via Portainer
4. **Using Portainer**:
    
    - Install Portainer for easy container management through a web interface
    - Useful for monitoring, restarting containers, and making minor configuration changes
    - For major changes, modify the original script and redeploy

### Example Script for Synology Task Scheduler

```bash
#!/bin/bash
# Script to deploy Jellyfin container
# Save in Synology Task Scheduler and run as root

# Stop and remove existing container if it exists
docker stop jellyfin
docker rm jellyfin

# Create the container
docker run -d --name=jellyfin \
  -v /volume2/Media/Peliculas:/movies \
  -v /volume1/docker/jellyfin/config:/config \
  -v /volume2/Media/Musica:/music \
  -v /volume1/docker/jellyfin/cache:/cache \
  -v /volume2/Media/Series:/series \
  -e PUID=1033 \
  -e PGID=100 \
  --group-add 937 \
  --net=host \
  --device /dev/dri/renderD128:/dev/dri/renderD128 \
  --device /dev/dri/card0:/dev/dri/card0 \
  --restart always \
  jellyfin/jellyfin

echo "Jellyfin container deployed successfully."
```

## Example Containers

### Media Server (Jellyfin)

```bash
docker run -d --name=jellyfin \
  -v /volume2/Media/Peliculas:/movies \
  -v /volume1/docker/jellyfin/config:/config \
  -v /volume2/Media/Musica:/music \
  -v /volume1/docker/jellyfin/cache:/cache \
  -v /volume2/Media/Series:/series \
  -e PUID=1033 \
  -e PGID=100 \
  --group-add 937 \
  --net=host \
  --device /dev/dri/renderD128:/dev/dri/renderD128 \
  --device /dev/dri/card0:/dev/dri/card0 \
  --restart always \
  jellyfin/jellyfin
```

This container:

- Runs in detached mode (`-d`)
- Mounts multiple volumes for media and configuration
- Sets user/group IDs for permissions
- Uses host networking for optimal performance
- Passes through GPU devices for hardware acceleration
- Automatically restarts if it crashes or on system boot

### Media Processing (Unmanic)

```bash
docker run -d --name=unmanic \
  -p 8888:8888 \
  -v /volume1/docker/unmanic/config:/config \
  -v /volume1/docker/unmanic/library:/library \
  -v /volume1/docker/unmanic/cache:/tmp/unmanic \
  -v /volume2/Media/Peliculas:/movies \
  -v /volume2/Media/Musica:/music \
  -v /volume2/Media/Series:/series \
  -e TZ=Europe/Roma \
  -e PUID=1033 \
  -e PGID=100 \
  --group-add 937 \
  --device /dev/dri/renderD128:/dev/dri/renderD128 \
  --device /dev/dri/card0:/dev/dri/card0 \
  --restart always \
  josh5/unmanic:latest
```

This container:

- Exposes port 8888 for web UI access
- Mounts volumes for configuration, processing, and media
- Sets timezone and user/group IDs
- Passes through GPU devices for hardware acceleration
- Automatically restarts if it crashes or on system boot

### Important Container Options Explained

- `-d`: Run in detached (background) mode
- `--name=NAME`: Assign a name to the container
- `-p HOST:CONTAINER`: Port mapping
- `-v HOST:CONTAINER`: Volume mapping
- `-e KEY=VALUE`: Environment variable
- `--restart always`: Automatically restart the container
- `--net=host`: Use host networking
- `--device SRC:DST`: Add a device to the container
- `--group-add GID`: Add additional groups to the container
- `-w PATH`: Set working directory inside the container
- `--user USER`: Set the user running the container
- `--memory LIMIT`: Set memory limit
- `--cpus LIMIT`: Set CPU limit
- `--privileged`: Give extended privileges to the container (use with caution)

## Installation

Docker installation varies by operating system:

- **Linux**:
    
    ```bash
    sudo apt-get update
    sudo apt-get install docker-ce docker-ce-cli containerd.io
    ```
    
- **macOS and Windows**: Download Docker Desktop from the [official website](https://www.docker.com/products/docker-desktop).
    

After installation, verify Docker is running:

```bash
docker --version
docker run hello-world
```

## Basic Docker Commands

### System Information

```bash
# View Docker system information
docker info

# Check Docker version
docker version

# Display system-wide information
docker system info

# Show disk usage
docker system df
```

### Help

```bash
# Get help on any command
docker [COMMAND] --help
```

## Working with Docker Images

Images are the blueprints for containers.

```bash
# List downloaded images
docker images

# Search for images on Docker Hub
docker search [IMAGE_NAME]

# Pull an image from a registry
docker pull [IMAGE_NAME]:[TAG]

# Build an image from a Dockerfile
docker build -t [IMAGE_NAME]:[TAG] [PATH_TO_DOCKERFILE]

# Remove an image
docker rmi [IMAGE_NAME]:[TAG]

# Remove all unused images
docker image prune
```

## Creating and Managing Containers

### Running Containers

```bash
# Run a container in interactive mode
docker run -it [IMAGE_NAME]:[TAG]

# Run a container in detached mode (background)
docker run -d [IMAGE_NAME]:[TAG]

# Run a container with a specific name
docker run --name [CONTAINER_NAME] [IMAGE_NAME]:[TAG]

# Run a container and automatically remove it when it exits
docker run --rm [IMAGE_NAME]:[TAG]

# Run a container with port mapping (host_port:container_port)
docker run -p 8080:80 [IMAGE_NAME]:[TAG]

# Run a container with environment variables
docker run -e VARIABLE_NAME=value [IMAGE_NAME]:[TAG]

# Run a container with a mounted volume
docker run -v /host/path:/container/path [IMAGE_NAME]:[TAG]
```

### Container Management

```bash
# List running containers
docker ps

# List all containers (including stopped)
docker ps -a

# Start a stopped container
docker start [CONTAINER_NAME or ID]

# Stop a running container
docker stop [CONTAINER_NAME or ID]

# Restart a container
docker restart [CONTAINER_NAME or ID]

# Pause a container
docker pause [CONTAINER_NAME or ID]

# Unpause a container
docker unpause [CONTAINER_NAME or ID]

# Remove a container
docker rm [CONTAINER_NAME or ID]

# Remove all stopped containers
docker container prune

# View container logs
docker logs [CONTAINER_NAME or ID]

# Follow container logs (stream)
docker logs -f [CONTAINER_NAME or ID]

# Execute a command in a running container
docker exec -it [CONTAINER_NAME or ID] [COMMAND]

# Open a shell inside a running container
docker exec -it [CONTAINER_NAME or ID] /bin/bash
```

## Docker Networking

```bash
# List networks
docker network ls

# Create a network
docker network create [NETWORK_NAME]

# Connect a container to a network
docker network connect [NETWORK_NAME] [CONTAINER_NAME]

# Disconnect a container from a network
docker network disconnect [NETWORK_NAME] [CONTAINER_NAME]

# Inspect a network
docker network inspect [NETWORK_NAME]

# Remove a network
docker network rm [NETWORK_NAME]
```

### Network Options

- `--net=host`: Uses the host's networking directly
- `--net=bridge`: Default network mode
- `--net=none`: No networking
- `--net=[NETWORK_NAME]`: Connect to a custom network

## Docker Volumes

Volumes are used for persistent data storage.

```bash
# List volumes
docker volume ls

# Create a volume
docker volume create [VOLUME_NAME]

# Inspect a volume
docker volume inspect [VOLUME_NAME]

# Remove a volume
docker volume rm [VOLUME_NAME]

# Remove all unused volumes
docker volume prune
```

### Volume Mounting Options

- `-v /host/path:/container/path`: Bind mount
- `-v [VOLUME_NAME]:/container/path`: Named volume
- `--mount type=bind,source=/host/path,target=/container/path`: Bind mount (alternative syntax)
- `--mount type=volume,source=[VOLUME_NAME],target=/container/path`: Named volume (alternative syntax)

## Docker Compose

Docker Compose is a tool for defining and running multi-container applications.

### Basic Commands

```bash
# Start services defined in docker-compose.yml
docker-compose up

# Start services in detached mode
docker-compose up -d

# Stop services
docker-compose down

# Stop services and remove volumes
docker-compose down -v

# View logs
docker-compose logs

# View running services
docker-compose ps
```

## Best Practices

1. **Use specific image tags** instead of `latest` for reproducibility
2. **Implement health checks** to ensure containers are functioning properly
3. **Use volumes for persistent data** to prevent data loss
4. **Minimize image size** by using multi-stage builds and alpine-based images
5. **Set resource limits** to prevent container resource exhaustion
6. **Use Docker Compose** for multi-container applications
7. **Follow least privilege principle** for security
8. **Regular cleanup** of unused containers, images, and volumes