Hermsi1337 / docker-sshd

Make your OpenSSH fly on Alpine

Overview

Use this Dockerfile / -image to start a slim and highly customizable sshd-server with bash and rsync installed.

Regular builds, automagically

Thanks to Travis-CI this image is pushed weekly and creates new tags if there are new versions available.

Tags

For recent tags check Dockerhub.

Features

• bash-shell and rsync installed
• Default .bashrc from ubuntu
• Desired shell is configurable by --env
• En- or disable root-user by --env
  • Choose between keypar and password auth for root
  • Password for root is configurable by --env
• Additional ssh-users can be created by --env
  • Authentication for additional users is done by keypair
• Beautifully colored log output

Usage examples

Authentication as root by password

$ docker run --rm \
--publish=1337:22 \
--env ROOT_PASSWORD=MyRootPW123 \
hermsi/alpine-sshd

After the container is up you are able to ssh in it as root with the in --env provided password for "root"-user.

$ ssh [email protected] -p 1337

Authentication as root by ssh-keypair

$ docker run --rm \
--publish=1337:22 \
--env ROOT_KEYPAIR_LOGIN_ENABLED=true \
--volume /path/to/authorized_keys:/root/.ssh/authorized_keys \
hermsi/alpine-sshd

After the container is up you are able to ssh in it as root with a private-key which matches the provided public-key in authorized_keys for "root"-user.

$ ssh [email protected] -p 1337 -i /path/to/private_key

Authenticate as additional user by ssh-keypair

$ docker run --rm \
--publish=1337:22 \
--env SSH_USERS="hermsi:1000:1000" \
--volume /path/to/hermsi_public_key:/conf.d/authorized_keys/hermsi \
hermsi/alpine-sshd

After the container is up you are able to ssh in it as the given user with a private-key that matches the provided public-key in authorized_keys for your created user.

$ ssh mydomain.tld -l hermsi -p 1337 -i /path/to/hermsi_private_key

Create multiple, additional users with keypair

$ docker run --rm \
--publish=1337:22 \
--env SSH_USERS="hermsi:1000:1000,dennis:1001:1001" \
--volume /path/to/hermsi_public_key:/conf.d/authorized_keys/hermsi \
--volume /path/to/dennis_public_key:/conf.d/authorized_keys/dennis \
hermsi/alpine-sshd

After the container is up you are able to ssh in it as one of the given users with a private-key that matches the provided public-key in authorized_keys for your desired user.

$ ssh [email protected] -p 1337 -i /path/to/private_key

Configuration

While beeing very slim and vanilla this image is still highly customizable.

Environment variables

Extending this image

This image is designed to be as slim and vanilla as possible.
If you need additional Tools like git , I definetly recommend to build your own image on top of alpine-sshd:

FROM  hermsi/alpine-sshd:latest

RUN   apk add --no-cache \
            git

Use with docker-compose

I built this image in order to use it along with a nginx and fpm-php container for transferring files via sftp. If you are interested in a Dockerfile which fulfills this need: this way