# Dynamic share mount into docker

## Introduction

Utilizing bind mounts in the stack/compose configuration allows the mounting of the root '/mnt' mount point into the Docker environment. Consequently, when a new share is added on the host side, it becomes available within the Docker system.

Notably, the file or directory does not need to exist on the Docker host beforehand; it is created on demand if absent. While bind mounts are highly performant, it is important to note that they depend on the host machine's filesystem having a specific directory structure available.

{% hint style="warning" %}
Exercise caution when using this function.\
The automatic/dynamic mounting of all sub-folders can pose a security risk. 

**We recommend discussing this internally with your IT department before proceeding.**
{% endhint %}

The required modifications for this are straightforward and easily implemented:

<figure><img src="https://content.gitbook.com/content/ttnkf7qEIoqtmdv6485i/blobs/zBninjoxxh3EySElHwu5/image.png" alt=""><figcaption><p>Volume mounting via bind</p></figcaption></figure>

Consider that the default basic /mnt:/Volumes mounting needs to be removed or changed to a comment, as this would lead to an issue when deploying the stack.

### Map root share

Configuration example for docker bind

```yaml
volumes:
      - type: bind
        bind:
          propagation: rslave
        source: /mnt
        target: /Volumes
      
      # Old static method to mount a share/folder
      #- /mnt:/Volumes    
```

<figure><img src="https://content.gitbook.com/content/ttnkf7qEIoqtmdv6485i/blobs/JWnK9nOE0aZwNhU7p8bh/bind-mount.gif" alt=""><figcaption><p>Demonstration of dynamic share mount in docker</p></figcaption></figure>

### Map dedicated folder

```yaml
volumes:
      - /etc/localtime:/etc/localtime:ro
      - type: bind
        bind:
          propagation: rslave
        source: /mnt/demo-h4/archive
        target: /Volumes/archive
```

{% hint style="info" %}
**For further information and assistance, here are the Docker references**\
\
[https://docs.docker.com/storage/bind-mounts](https://docs.docker.com/storage/bind-mounts/)\
<https://docs.docker.com/storage/bind-mounts/#configure-bind-propagation>
{% endhint %}