%entities; ]> systemd systemd-ssh-generator 8 systemd-ssh-generator Generator for binding a socket-activated SSH server to local AF_VSOCK and AF_UNIX sockets /usr/lib/systemd/system-generators/systemd-ssh-generator systemd-ssh-generator binds a socket-activated SSH server to local AF_VSOCK and AF_UNIX sockets under certain conditions. It only has an effect if the sshd8 binary is installed. Specifically, it does the following: If invoked in a VM with AF_VSOCK support, a socket-activated SSH per-connection service is bound to AF_VSOCK port 22. If invoked in a container environment with a writable directory /run/host/unix-export/ pre-mounted it binds SSH to an AF_UNIX socket /run/host/unix-export/ssh. The assumption is that this directory is bind mounted to the host side as well, and can be used to connect to the container from there. See Container Interface for more information about this interface. A local AF_UNIX socket /run/ssh-unix-local/socket is also bound, unconditionally. This may be used for SSH communication from the host to itself, without involving networking, for example to traverse security boundaries safely and with secure authentication. Additional AF_UNIX and AF_VSOCK sockets are optionally bound, based on the systemd.ssh_listen= kernel command line option or the ssh.listen system credential (see below). See systemd-ssh-proxy1 for details on how to connect to these sockets via the ssh client. The ssh.authorized_keys.root credential can be used to allow specific public keys to log in over SSH. See systemd.system-credentials7 for more information. The generator will use a packaged sshd@.service service template file if one exists, and otherwise generate a suitable service template file. systemd-ssh-generator implements systemd.generator7. systemd-ssh-generator understands the following kernel-command-line7 parameters: systemd.ssh_auto= This option takes an optional boolean argument, and defaults to yes. If enabled, the automatic binding to the AF_VSOCK and AF_UNIX sockets listed above is done. If disable, this is not done, except for those explicitly requested via systemd.ssh_listen= on the kernel command line or via the ssh.listen system credential. systemd.ssh_listen= This option configures an additional socket to bind SSH to. It may be used multiple times to bind multiple sockets. The syntax should follow the one of ListenStream=, see systemd.socket5 for details. This functionality supports all socket families systemd supports, including AF_INET and AF_INET6. systemd-ssh-generator supports the system credentials logic. The following credentials are used when passed in: ssh.listen This credential should be a text file, with each line referencing one additional socket to bind SSH to. The syntax should follow the one of ListenStream=, see systemd.socket5 for details. This functionality supports all socket families systemd supports, including AF_INET and AF_INET6. systemd1 kernel-command-line7 systemd.system-credentials7 vsock7 unix7 ssh1 sshd8