[Openssh-server](https://www.openssh.com/) 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.
We utilise the docker manifest for multi-platform awareness. More information is available from docker [here](https://distribution.github.io/distribution/spec/manifest-v2-2/#manifest-list) and our announcement [here](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.
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.
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 [in this blog article](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.
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.
| `PUBLIC_KEY_DIR=/path/to/directory/containing/_only_/pubkeys` | Optionally specify a directory containing the public keys (works with docker secrets). |
| `SUDO_ACCESS=false` | Set to `true` to allow `linuxserver.io`, the ssh user, sudo access. Without `USER_PASSWORD` set, this will allow passwordless sudo access. |
| `PASSWORD_ACCESS=false` | Set to `true` to allow user/password ssh access. You will want to set `USER_PASSWORD` or `USER_PASSWORD_FILE` as well. |
| `USER_PASSWORD=password` | Optionally set a sudo password for `linuxserver.io`, the ssh user. If this or `USER_PASSWORD_FILE` are not set but `SUDO_ACCESS` is set to true, the user will have passwordless sudo access. |
| `USER_PASSWORD_FILE=/path/to/file` | Optionally specify a file that contains the password. This setting supersedes the `USER_PASSWORD` option (works with docker secrets). |
| `USER_NAME=linuxserver.io` | Optionally specify a user name (Default:`linuxserver.io`) |
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](https://en.wikipedia.org/wiki/Umask) before asking for support.
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`.
[](https://mods.linuxserver.io/?mod=openssh-server "view available mods for this container.") [](https://mods.linuxserver.io/?mod=universal "view available universal mods.")
We publish various [Docker Mods](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.
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](#application-setup) section above to see if it is recommended for the image.
* 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)
We recommend [Diun](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:
