f535d6f45e
We need to move NixOS containers somewhere else so these don't clash with Podman, Skopeo & other container software in the libpod & cri-o/cri-u/libcontainer ecosystems. The state directory move is not strictly a requirement but is good for consistency.
61 lines
2.4 KiB
XML
61 lines
2.4 KiB
XML
<section xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="sec-declarative-containers">
|
||
<title>Declarative Container Specification</title>
|
||
<para>
|
||
You can also specify containers and their configuration in the
|
||
host’s <literal>configuration.nix</literal>. For example, the
|
||
following specifies that there shall be a container named
|
||
<literal>database</literal> running PostgreSQL:
|
||
</para>
|
||
<programlisting language="bash">
|
||
containers.database =
|
||
{ config =
|
||
{ config, pkgs, ... }:
|
||
{ services.postgresql.enable = true;
|
||
services.postgresql.package = pkgs.postgresql_10;
|
||
};
|
||
};
|
||
</programlisting>
|
||
<para>
|
||
If you run <literal>nixos-rebuild switch</literal>, the container
|
||
will be built. If the container was already running, it will be
|
||
updated in place, without rebooting. The container can be configured
|
||
to start automatically by setting
|
||
<literal>containers.database.autoStart = true</literal> in its
|
||
configuration.
|
||
</para>
|
||
<para>
|
||
By default, declarative containers share the network namespace of
|
||
the host, meaning that they can listen on (privileged) ports.
|
||
However, they cannot change the network configuration. You can give
|
||
a container its own network as follows:
|
||
</para>
|
||
<programlisting language="bash">
|
||
containers.database = {
|
||
privateNetwork = true;
|
||
hostAddress = "192.168.100.10";
|
||
localAddress = "192.168.100.11";
|
||
};
|
||
</programlisting>
|
||
<para>
|
||
This gives the container a private virtual Ethernet interface with
|
||
IP address <literal>192.168.100.11</literal>, which is hooked up to
|
||
a virtual Ethernet interface on the host with IP address
|
||
<literal>192.168.100.10</literal>. (See the next section for details
|
||
on container networking.)
|
||
</para>
|
||
<para>
|
||
To disable the container, just remove it from
|
||
<literal>configuration.nix</literal> and run
|
||
<literal>nixos-rebuild switch</literal>. Note that this will not
|
||
delete the root directory of the container in
|
||
<literal>/var/lib/nixos-containers</literal>. Containers can be
|
||
destroyed using the imperative method:
|
||
<literal>nixos-container destroy foo</literal>.
|
||
</para>
|
||
<para>
|
||
Declarative containers can be started and stopped using the
|
||
corresponding systemd service, e.g.
|
||
<literal>systemctl start container@database</literal>.
|
||
</para>
|
||
</section>
|