atmoz/sftp
==========

Easy to use SFTP ([SSH File Transfer Protocol](https://en.wikipedia.org/wiki/SSH_File_Transfer_Protocol)) server with [OpenSSH](https://en.wikipedia.org/wiki/OpenSSH). This is an automated build linked with the [debian](https://hub.docker.com/_/debian/) repository.

Usage
-----

- Define users as command arguments, STDIN or mounted in /etc/sftp-users.conf
  (syntax: `user:pass[:e][:uid[:gid]]...`).
  - You must set custom UID for your users if you want them to make changes to
    your mounted volumes with permissions matching your host filesystem.
- Mount volumes in user's home folder.
  - The users are chrooted to their home directory, so you must mount the
    volumes in separate directories inside the user's home directory
    (/home/user/**mounted-directory**).

Examples
--------

### Simple docker run example

```
docker run \
    -v /host/share:/home/foo/share \
    -p 2222:22 -d atmoz/sftp \
    foo:123:1001
```

#### Using Docker Compose:

```
sftp:
    image: atmoz/sftp
    volumes:
        - /host/share:/home/foo/share
    ports:
        - "2222:22"
    command: foo:123:1001
```

#### Logging in

The OpenSSH server runs by default on port 22, and in this example, we are
forwarding the container's port 22 to the host's port 2222. To log in with the
OpenSSH client, run: `sftp -P 2222 foo@<host-ip>`

### Store users in config

```
docker run \
    -v /host/users.conf:/etc/sftp-users.conf:ro \
    -v /host/share:/home/foo/share \
    -v /host/documents:/home/foo/documents \
    -v /host/http:/home/bar/http \
    -p 2222:22 -d atmoz/sftp
```

/host/users.conf:

```
foo:123:1001
bar:abc:1002
```

### Encrypted password

Add `:e` behind password to mark it as encrypted. Use single quotes if using terminal.

```
docker run \
    -v /host/share:/home/foo/share \
    -p 2222:22 -d atmoz/sftp \
    'foo:$1$0G2g0GSt$ewU0t6GXG15.0hWoOX8X9.:e:1001'
```

Tip: you can use makepasswd to generate encrypted passwords:  
`echo -n "password" | makepasswd --crypt-md5 --clearfrom -`

### Using SSH key (without password)

Mount all public keys in the user's `.ssh/keys/` folder. All keys are automatically
appended to `.ssh/authorized_keys`.

```
docker run \
    -v /host/id_rsa.pub:/home/foo/.ssh/keys/id_rsa.pub:ro \
    -v /host/id_other.pub:/home/foo/.ssh/keys/id_other.pub:ro \
    -v /host/share:/home/foo/share \
    -p 2222:22 -d atmoz/sftp \
    foo::1001
```

### Execute custom scripts or applications

Put your programs in /etc/sftp.d/ and it will automatically run when the container starts.
See next section for an example.

### Bindmount dirs from another location

If you are using --volumes-from or just want to make a custom directory
available in user's home directory, you can add a script to /etc/sftp.d/ that
bindmounts after container starts.

```
#!/bin/bash
# Just an example (make your own):
function bindmount() {
    if [ -d "$1" ]; then
        mkdir -p "$2"
    fi
    mount --bind $3 "$1" "$2"
}

# Remember permissions, you may have to fix it:
# chown -R :users /data/common

bindmount /data/admin-tools /home/admin/tools
bindmount /data/common /home/dave/common
bindmount /data/common /home/peter/common
bindmount /data/docs /home/peter/docs --read-only
```