Imperative Container Management We’ll cover imperative container management using nixos-container first. Be aware that container management is currently only possible as root. You create a container with identifier foo as follows: # nixos-container create foo This creates the container’s root directory in /var/lib/containers/foo and a small configuration file in /etc/containers/foo.conf. It also builds the container’s initial system configuration and stores it in /nix/var/nix/profiles/per-container/foo/system. You can modify the initial configuration of the container on the command line. For instance, to create a container that has sshd running, with the given public key for root: # nixos-container create foo --config 'services.openssh.enable = true; \ users.extraUsers.root.openssh.authorizedKeys.keys = ["ssh-dss AAAAB3N…"];' Creating a container does not start it. To start the container, run: # nixos-container start foo This command will return as soon as the container has booted and has reached multi-user.target. On the host, the container runs within a systemd unit called container@container-name.service. Thus, if something went wrong, you can get status info using systemctl: # systemctl status container@foo If the container has started succesfully, you can log in as root using the root-login operation: # nixos-container root-login foo [root@foo:~]# Note that only root on the host can do this (since there is no authentication). You can also get a regular login prompt using the login operation, which is available to all users on the host: # nixos-container login foo foo login: alice Password: *** With nixos-container run, you can execute arbitrary commands in the container: # nixos-container run foo -- uname -a Linux foo 3.4.82 #1-NixOS SMP Thu Mar 20 14:44:05 UTC 2014 x86_64 GNU/Linux There are several ways to change the configuration of the container. First, on the host, you can edit /var/lib/container/name/etc/nixos/configuration.nix, and run # nixos-container update foo This will build and activate the new configuration. You can also specify a new configuration on the command line: # nixos-container update foo --config 'services.httpd.enable = true; \ services.httpd.adminAddr = "foo@example.org";' # curl http://$(nixos-container show-ip foo)/ <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">… However, note that this will overwrite the container’s /etc/nixos/configuration.nix. Alternatively, you can change the configuration from within the container itself by running nixos-rebuild switch inside the container. Note that the container by default does not have a copy of the NixOS channel, so you should run nix-channel --update first. Containers can be stopped and started using nixos-container stop and nixos-container start, respectively, or by using systemctl on the container’s service unit. To destroy a container, including its file system, do # nixos-container destroy foo