OpenSSH Server Docker Image

The https://linuxserver.io team brings you another container release featuring:

• regular and timely application updates
• easy user mappings (PGID, PUID)
• custom base image with s6 overlay
• weekly base OS updates with common layers across the entire LinuxServer.io ecosystem to minimise space usage, down time and bandwidth
• regular security updates

Find us at:

• https://blog.linuxserver.io - all the things you can do with our containers including How-To guides, opinions and much more!
• https://linuxserver.io/*** - realtime support / chat with the community and the team.
• https://github.com/orgs/linuxserver/discussions - post on our community forum.
• https://github.com/linuxserver - view the source for all of our repositories.
• https://opencollective.com/linuxserver - please *** helping us by either donating or contributing to our budget

https://github.com/linuxserver/docker-openssh-server

Openssh-server is a sandboxed environment that allows ssh access without giving keys to the entire server. Giving ssh access via private key often means giving full access to the server. This container creates a limited and sandboxed environment that others can ssh into. The users only have access to the folders mapped and the processes running inside this container.

Supported Architectures

We utilise the docker manifest for multi-platform awareness. More information is available from docker https://distribution.github.io/distribution/spec/manifest-v2-2/#manifest-list and our announcement https://blog.linuxserver.io/2019/02/21/the-lsio-pipeline-project/.

Simply pulling lscr.io/linuxserver/openssh-server:latest should retrieve the correct image for your arch, but you can also pull specific arch images via tags.

The architectures supported by this image are:

Application Setup

If PUBLIC_KEY or PUBLIC_KEY_FILE, or PUBLIC_KEY_DIR variables are set, the specified keys will automatically be added to authorized_keys. If not, the keys can manually be added to /config/.ssh/authorized_keys and the container should be restarted. Removing PUBLIC_KEY or PUBLIC_KEY_FILE variables from docker run environment variables will not remove the keys from authorized_keys. PUBLIC_KEY_FILE and PUBLIC_KEY_DIR can be used with docker secrets.

We provide the ability to set and allow password based access via the PASSWORD_ACCESS and USER_PASSWORD variables, though we as an organization discourage using password auth for public facing ssh endpoints.

Connect to server via ssh -i /path/to/private/key -p PORT USER_NAME@SERVERIP

Setting SUDO_ACCESS to true by itself will allow passwordless sudo. USER_PASSWORD and USER_PASSWORD_FILE allow setting an optional sudo password.

The users only have access to the folders mapped and the processes running inside this container. Add any volume mappings you like for the users to have access to. To install packages or services for users to access, use the LinuxServer container customization methods described https://blog.linuxserver.io/2019/09/14/customizing-our-containers/.

Sample use case is when a server admin would like to have automated incoming backups from a remote server to the local server, but they might not want all the other admins of the remote server to have full access to the local server. This container can be set up with a mounted folder for incoming backups, and rsync installed via LinuxServer container customization described above, so that the incoming backups can proceed, but remote server and its admins' access would be limited to the backup folder.

It is also possible to run multiple copies of this container with different ports mapped, different folders mounted and access to different private keys for compartmentalized access.

TIPS

You can volume map your own text file to /etc/motd to override the message displayed upon connection. You can optionally set the docker argument hostname

Key Generation

This container has a helper script to generate an ssh private/public key. In order to generate a key please run:

docker run --rm -it --entrypoint /keygen.sh linuxserver/openssh-server

Then simply follow the prompts. The keys generated by this script are only displayed on your console output, so make sure to save them somewhere after generation.

Usage

To help you get started creating a container from this image you can either use docker-compose or the docker cli.

[!NOTE] Unless a parameter is flagged as 'optional', it is mandatory and a value must be provided.

docker-compose (recommended, https://docs.linuxserver.io/general/docker-compose)

yaml
---
services:
  openssh-server:
    image: lscr.io/linuxserver/openssh-server:latest
    container_name: openssh-server
    hostname: openssh-server #optional
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Etc/UTC
      - PUBLIC_KEY=yourpublickey #optional
      - PUBLIC_KEY_FILE=/path/to/file #optional
      - PUBLIC_KEY_DIR=/path/to/directory/containing/_only_/pubkeys #optional
      - PUBLIC_KEY_URL=https://github.com/username.keys #optional
      - SUDO_ACCESS=false #optional
      - PASSWORD_ACCESS=false #optional
      - USER_PASSWORD=password #optional
      - USER_PASSWORD_FILE=/path/to/file #optional
      - USER_NAME=linuxserver.io #optional
      - LOG_STDOUT= #optional
    volumes:
      - /path/to/openssh-server/config:/config
    ports:
      - 2222:2222
    restart: unless-stopped

docker cli (https://docs.docker.com/engine/reference/commandline/cli/)

bash
docker run -d \
  --name=openssh-server \
  --hostname=openssh-server `#optional` \
  -e PUID=1000 \
  -e PGID=1000 \
  -e TZ=Etc/UTC \
  -e PUBLIC_KEY=yourpublickey `#optional` \
  -e PUBLIC_KEY_FILE=/path/to/file `#optional` \
  -e PUBLIC_KEY_DIR=/path/to/directory/containing/_only_/pubkeys `#optional` \
  -e PUBLIC_KEY_URL=https://github.com/username.keys `#optional` \
  -e SUDO_ACCESS=false `#optional` \
  -e PASSWORD_ACCESS=false `#optional` \
  -e USER_PASSWORD=password `#optional` \
  -e USER_PASSWORD_FILE=/path/to/file `#optional` \
  -e USER_NAME=linuxserver.io `#optional` \
  -e LOG_STDOUT= `#optional` \
  -p 2222:2222 \
  -v /path/to/openssh-server/config:/config \
  --restart unless-stopped \
  lscr.io/linuxserver/openssh-server:latest

Parameters

Containers are configured using parameters passed at runtime (such as those above). These parameters are separated by a colon and indicate <external>:<internal> respectively. For example, -p 8080:80 would expose port 80 from inside the container to be accessible from the host's IP on port 8080 outside the container.

Environment variables from files (Docker secrets)

You can set any environment variable from a file by using a special prepend FILE__.

As an example:

bash
-e FILE__MYVAR=/run/secrets/mysecretvariable

Will set the environment variable MYVAR based on the contents of the /run/secrets/mysecretvariable file.

Umask for running applications

For all of our images we provide the ability to override the default umask settings for services started within the containers using the optional -e UMASK=022 setting. Keep in mind umask is not chmod it subtracts from permissions based on it's value it does not add. Please read up here before asking for support.

User / Group Identifiers

When using volumes (-v flags), permissions issues can arise between the host OS and the container, we avoid this issue by allowing you to specify the user PUID and group PGID.

Ensure any volume directories on the host are owned by the same user you specify and any permissions issues will vanish like magic.

In this instance PUID=1000 and PGID=1000, to find yours use id your_user as below:

bash
id your_user

Example output:

text
uid=1000(your_user) gid=1000(your_user) groups=1000(your_user)

Docker Mods

We publish various https://github.com/linuxserver/docker-mods to enable additional functionality within the containers. The list of Mods available for this image (if any) as well as universal mods that can be applied to any one of our images can be accessed via the dynamic badges above.

Support Info

• Shell access whilst the container is running:

  bash
  docker exec -it openssh-server /bin/bash
  

• To monitor the logs of the container in realtime:

  bash
  docker logs -f openssh-server
  

• Container version number:

  bash
  docker inspect -f '{{ index .Config.Labels "build_version" }}' openssh-server
  

• Image version number:

  bash
  docker inspect -f '{{ index .Config.Labels "build_version" }}' lscr.io/linuxserver/openssh-server:latest
  

Updating Info

Most of our images are static, versioned, and require an image update and container recreation to update the app inside. With some exceptions (noted in the relevant readme.md), we do not recommend or support updating apps inside the container. Please consult the Application Setup section above to see if it is recommended for the image.

Below are the instructions for updating containers:

Via Docker Compose

• Update images:

  • All images:

    bash
    docker-compose pull
    

  • Single image:

    bash
    docker-compose pull openssh-server
    

• Update containers:

  • All containers:

    bash
    docker-compose up -d
    

  • Single container:

    bash
    docker-compose up -d openssh-server
    

• You can also remove the old dangling images:

  bash
  docker image prune
  

Via Docker Run

• Update the image:

  bash
  docker pull lscr.io/linuxserver/openssh-server:latest
  

• Stop the running container:

  bash
  docker stop openssh-server
  

• Delete the container:

  bash
  docker rm openssh-server
  

• Recreate a new container with the same docker run parameters as instructed above (if mapped correctly to a host folder, your /config folder and settings will be preserved)

• You can also remove the old dangling images:

  bash
  docker image prune
  

Image Update Notifications - Diun (Docker Image Update Notifier)

[!TIP] We recommend https://crazymax.dev/diun/ for update notifications. Other tools that automatically update containers unattended are not recommended or supported.

Building locally

If you want to make local modifications to these images for development purposes or just to customize the logic:

bash
git clone https://github.com/linuxserver/docker-openssh-server.git
cd docker-openssh-server
docker build \
  --no-cache \
  --pull \
  -t lscr.io/linuxserver/openssh-server:latest .

The ARM variants can be built on x86_64 hardware and vice versa using lscr.io/linuxserver/qemu-static

bash
docker run --rm --privileged lscr.io/linuxserver/qemu-static --reset

Once registered you can define the dockerfile to use with -f Dockerfile.aarch64.

Versions

• 05.07.26: - Rebase to Alpine 3.24.
• 28.12.25: - Rebase to Alpine 3.23.
• 05.07.25: - Rebase to Alpine 3.22.
• 10.02.25: - Add support for sshd_config.d
• 12.01.25: - Rebase to Alpine 3.21.
• 24.11.24: - Move sshd_config to /config/sshd/sshd_config.
• 31.05.24: - Rebase to Alpine 3.20.
• 04.05.24: - Display the SSH host public keys every time the container starts.
• 09.03.24: - Rebase to Alpine 3.19.
• 12.06.23: - Rebase to Alpine 3.18, deprecate armhf. As announced https://www.linuxserver.io/blog/a-farewell-to-arm-hf
• 05.03.23: - Rebase to Alpine 3.17.
• 18.10.22: - Fix wrong behavior of password/passwordless sudo
• 11.10.22: - Rebase to Alpine 3.16, migrate to s6v3.
• 15.09.22: - add netcat-openbsd with support for proxies.
• 18.07.22: - Fix service perms to comply with upgrade to s6 v3.
• 16.04.22: - Rebase to alpine 3.15.
• 16.11.21: - Add PUBLIC_KEY_URL option
• 28.06.21: - Rebasing to alpine 3.14. Add support for PAM.
• 10.02.21: - Rebasing to alpine 3.13. Add openssh-client for scp.
• 21.10.20: - Implement s6-log for openssh, which adds local timestamps to logs and can be used with a log parser like fail2ban.
• 20.10.20: - Set umask for sftp.
• 01.06.20: - Rebasing to alpine 3.12.
• 18.01.20: - Add key generation script.
• 13.01.20: - Add openssh-sftp-server.
• 19.12.19: - Rebasing to alpine 3.11.
• 17.10.19: - Initial Release.