Supported tags and respective Dockerfile links

• debian-jessie, debian, latest (Dockerfile)
• alpine-3.4, alpine (Dockerfile)

Securely share your files

Easy to use SFTP (SSH File Transfer Protocol) server with OpenSSH. This is an automated build linked with the debian and alpine repositories.

Usage

• Define users as command arguments, STDIN or mounted in /etc/sftp-users.conf (syntax: user:pass[:e][:uid[:gid[:dir1[,dir2]...]]]...).
  • Set UID/GID manually for your users if you want them to make changes to your mounted volumes with permissions matching your host filesystem.
  • Add directory names at the end, if you want to create them and/or set user ownership. Perfect when you just want a fast way to upload something without mounting any directories, or you want to make sure a directory is owned by a user (chown -R).
• Mount volumes in user's home directory.
  • 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

Simplest docker run example

docker run -p 22:22 -d atmoz/sftp foo:pass:::upload

User "foo" with password "pass" can login with sftp and upload files to a folder called "upload". No mounted directories or custom UID/GID. Later you can inspect the files and use --volumes-from to mount them somewhere else (or see next example).

Sharing a directory from your computer

Let's mount a directory and set UID:

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 atmoz/makepasswd to generate encrypted passwords:
echo -n "your-password" | docker run -i --rm atmoz/makepasswd --crypt-md5 --clearfrom=-

Using SSH key (and no password)

Mount all public keys in the user's .ssh/keys/ directory. 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

Using custom SSH key for server

This container will generate an ssh-key for OpenSSH at first run. To avoid this, you can map Ed25519 or RSA keys from the host inside the container.

#for ed25519 keys:
docker run \
    -v /host/ssh_host_ed25519_key:/etc/ssh/ssh_host_ed25519_key \
    -v /host/share:/home/foo/share \
    -p 2222:22 -d atmoz/sftp \
    foo::1001
#Tip: you can generate an Ed25519 key with this command: `ssh-keygen -t ed25519 -f /host/ssh_host_ed25519_key < /dev/null`
    
#for rsa keys:
docker run \
    -v /host/ssh_host_rsa_key:/etc/ssh/ssh_host_rsa_key \
    -v /host/share:/home/foo/share \
    -p 2222:22 -d atmoz/sftp \
    foo::1001
#Tip: you can generate an rsa key with this command: `ssh-keygen -t rsa -b 4096 -f /etc/ssh/ssh_host_rsa_key < /dev/null`

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
# File mounted as: /etc/sftp.d/bindmount.sh
# 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 them:
# 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