nixpkgs/nixos/modules/virtualisation/containers.nix

773 lines
25 KiB
Nix
Raw Normal View History

{ config, lib, pkgs, ... }:
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
with lib;
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
let
# The container's init script, a small wrapper around the regular
# NixOS stage-2 init script.
containerInit = (cfg:
let
renderExtraVeth = (name: cfg:
''
echo "Bringing ${name} up"
ip link set dev ${name} up
${optionalString (cfg.localAddress != null) ''
echo "Setting ip for ${name}"
ip addr add ${cfg.localAddress} dev ${name}
''}
${optionalString (cfg.localAddress6 != null) ''
echo "Setting ip6 for ${name}"
ip -6 addr add ${cfg.localAddress6} dev ${name}
''}
${optionalString (cfg.hostAddress != null) ''
echo "Setting route to host for ${name}"
ip route add ${cfg.hostAddress} dev ${name}
''}
${optionalString (cfg.hostAddress6 != null) ''
echo "Setting route6 to host for ${name}"
ip -6 route add ${cfg.hostAddress6} dev ${name}
''}
''
);
in
pkgs.writeScript "container-init"
''
#! ${pkgs.runtimeShell} -e
# Initialise the container side of the veth pair.
if [ -n "$HOST_ADDRESS" ] || [ -n "$LOCAL_ADDRESS" ] || [ -n "$HOST_BRIDGE" ]; then
ip link set host0 name eth0
ip link set dev eth0 up
if [ -n "$LOCAL_ADDRESS" ]; then
ip addr add $LOCAL_ADDRESS dev eth0
fi
if [ -n "$LOCAL_ADDRESS6" ]; then
ip -6 addr add $LOCAL_ADDRESS6 dev eth0
fi
if [ -n "$HOST_ADDRESS" ]; then
ip route add $HOST_ADDRESS dev eth0
ip route add default via $HOST_ADDRESS
fi
if [ -n "$HOST_ADDRESS6" ]; then
ip -6 route add $HOST_ADDRESS6 dev eth0
ip -6 route add default via $HOST_ADDRESS6
fi
${concatStringsSep "\n" (mapAttrsToList renderExtraVeth cfg.extraVeths)}
fi
# Start the regular stage 1 script.
exec "$1"
''
);
nspawnExtraVethArgs = (name: cfg: "--network-veth-extra=${name}");
startScript = cfg:
''
mkdir -p -m 0755 "$root/etc" "$root/var/lib"
mkdir -p -m 0700 "$root/var/lib/private" "$root/root" /run/containers
if ! [ -e "$root/etc/os-release" ]; then
touch "$root/etc/os-release"
fi
if ! [ -e "$root/etc/machine-id" ]; then
touch "$root/etc/machine-id"
fi
mkdir -p -m 0755 \
"/nix/var/nix/profiles/per-container/$INSTANCE" \
"/nix/var/nix/gcroots/per-container/$INSTANCE"
cp --remove-destination /etc/resolv.conf "$root/etc/resolv.conf"
if [ "$PRIVATE_NETWORK" = 1 ]; then
extraFlags+=" --private-network"
fi
if [ -n "$HOST_ADDRESS" ] || [ -n "$LOCAL_ADDRESS" ]; then
extraFlags+=" --network-veth"
fi
if [ -n "$HOST_PORT" ]; then
OIFS=$IFS
IFS=","
for i in $HOST_PORT
do
extraFlags+=" --port=$i"
done
IFS=$OIFS
fi
if [ -n "$HOST_BRIDGE" ]; then
extraFlags+=" --network-bridge=$HOST_BRIDGE"
fi
extraFlags+=" ${concatStringsSep " " (mapAttrsToList nspawnExtraVethArgs cfg.extraVeths)}"
for iface in $INTERFACES; do
extraFlags+=" --network-interface=$iface"
done
for iface in $MACVLANS; do
extraFlags+=" --network-macvlan=$iface"
done
# If the host is 64-bit and the container is 32-bit, add a
# --personality flag.
${optionalString (config.nixpkgs.localSystem.system == "x86_64-linux") ''
if [ "$(< ''${SYSTEM_PATH:-/nix/var/nix/profiles/per-container/$INSTANCE/system}/system)" = i686-linux ]; then
extraFlags+=" --personality=x86"
fi
''}
# Run systemd-nspawn without startup notification (we'll
# wait for the container systemd to signal readiness).
exec ${config.systemd.package}/bin/systemd-nspawn \
--keep-unit \
-M "$INSTANCE" -D "$root" $extraFlags \
$EXTRA_NSPAWN_FLAGS \
--notify-ready=yes \
--bind-ro=/nix/store \
--bind-ro=/nix/var/nix/db \
--bind-ro=/nix/var/nix/daemon-socket \
--bind="/nix/var/nix/profiles/per-container/$INSTANCE:/nix/var/nix/profiles" \
--bind="/nix/var/nix/gcroots/per-container/$INSTANCE:/nix/var/nix/gcroots" \
--link-journal=try-guest \
--setenv PRIVATE_NETWORK="$PRIVATE_NETWORK" \
--setenv HOST_BRIDGE="$HOST_BRIDGE" \
--setenv HOST_ADDRESS="$HOST_ADDRESS" \
--setenv LOCAL_ADDRESS="$LOCAL_ADDRESS" \
--setenv HOST_ADDRESS6="$HOST_ADDRESS6" \
--setenv LOCAL_ADDRESS6="$LOCAL_ADDRESS6" \
--setenv HOST_PORT="$HOST_PORT" \
--setenv PATH="$PATH" \
${if cfg.additionalCapabilities != null && cfg.additionalCapabilities != [] then
''--capability="${concatStringsSep " " cfg.additionalCapabilities}"'' else ""
} \
${if cfg.tmpfs != null && cfg.tmpfs != [] then
''--tmpfs=${concatStringsSep " --tmpfs=" cfg.tmpfs}'' else ""
} \
${containerInit cfg} "''${SYSTEM_PATH:-/nix/var/nix/profiles/system}/init"
'';
preStartScript = cfg:
''
# Clean up existing machined registration and interfaces.
machinectl terminate "$INSTANCE" 2> /dev/null || true
if [ -n "$HOST_ADDRESS" ] || [ -n "$LOCAL_ADDRESS" ]; then
ip link del dev "ve-$INSTANCE" 2> /dev/null || true
ip link del dev "vb-$INSTANCE" 2> /dev/null || true
fi
${concatStringsSep "\n" (
mapAttrsToList (name: cfg:
''ip link del dev ${name} 2> /dev/null || true ''
) cfg.extraVeths
)}
'';
postStartScript = (cfg:
let
ipcall = cfg: ipcmd: variable: attribute:
if cfg.${attribute} == null then
''
if [ -n "${variable}" ]; then
${ipcmd} add ${variable} dev $ifaceHost
fi
''
else
''${ipcmd} add ${cfg.${attribute}} dev $ifaceHost'';
renderExtraVeth = name: cfg:
if cfg.hostBridge != null then
''
# Add ${name} to bridge ${cfg.hostBridge}
ip link set dev ${name} master ${cfg.hostBridge} up
''
else
''
echo "Bring ${name} up"
ip link set dev ${name} up
# Set IPs and routes for ${name}
${optionalString (cfg.hostAddress != null) ''
ip addr add ${cfg.hostAddress} dev ${name}
''}
${optionalString (cfg.hostAddress6 != null) ''
ip -6 addr add ${cfg.hostAddress6} dev ${name}
''}
${optionalString (cfg.localAddress != null) ''
ip route add ${cfg.localAddress} dev ${name}
''}
${optionalString (cfg.localAddress6 != null) ''
ip -6 route add ${cfg.localAddress6} dev ${name}
''}
'';
in
''
if [ -n "$HOST_ADDRESS" ] || [ -n "$LOCAL_ADDRESS" ]; then
if [ -z "$HOST_BRIDGE" ]; then
ifaceHost=ve-$INSTANCE
ip link set dev $ifaceHost up
${ipcall cfg "ip addr" "$HOST_ADDRESS" "hostAddress"}
${ipcall cfg "ip -6 addr" "$HOST_ADDRESS6" "hostAddress6"}
${ipcall cfg "ip route" "$LOCAL_ADDRESS" "localAddress"}
${ipcall cfg "ip -6 route" "$LOCAL_ADDRESS6" "localAddress6"}
fi
${concatStringsSep "\n" (mapAttrsToList renderExtraVeth cfg.extraVeths)}
fi
# Get the leader PID so that we can signal it in
# preStop. We can't use machinectl there because D-Bus
# might be shutting down. FIXME: in systemd 219 we can
# just signal systemd-nspawn to do a clean shutdown.
machinectl show "$INSTANCE" | sed 's/Leader=\(.*\)/\1/;t;d' > "/run/containers/$INSTANCE.pid"
''
);
serviceDirectives = cfg: {
ExecReload = pkgs.writeScript "reload-container"
''
#! ${pkgs.runtimeShell} -e
${pkgs.nixos-container}/bin/nixos-container run "$INSTANCE" -- \
bash --login -c "''${SYSTEM_PATH:-/nix/var/nix/profiles/system}/bin/switch-to-configuration test"
'';
SyslogIdentifier = "container %i";
EnvironmentFile = "-/etc/containers/%i.conf";
Type = "notify";
# Note that on reboot, systemd-nspawn returns 133, so this
# unit will be restarted. On poweroff, it returns 0, so the
# unit won't be restarted.
RestartForceExitStatus = "133";
SuccessExitStatus = "133";
Restart = "on-failure";
nixos/containers: Introduce several tweaks to systemd-nspawn from upstream systemd * Lets container@.service be activated by machines.target instead of multi-user.target According to the systemd manpages, all containers that are registered by machinectl, should be inside machines.target for easy stopping and starting container units altogether * make sure container@.service and container.slice instances are actually located in machine.slice https://plus.google.com/112206451048767236518/posts/SYAueyXHeEX See original commit: https://github.com/NixOS/systemd/commit/45d383a3b8 * Enable Cgroup delegation for nixos-containers Delegate=yes should be set for container scopes where a systemd instance inside the container shall manage the hierarchies below its own cgroup and have access to all controllers. This is equivalent to enabling all accounting options on the systemd process inside the system container. This means that systemd inside the container is responsible for managing Cgroup resources for unit files that enable accounting options inside. Without this option, units that make use of cgroup features within system containers might misbehave See original commit: https://github.com/NixOS/systemd/commit/a931ad47a8 from the manpage: Turns on delegation of further resource control partitioning to processes of the unit. Units where this is enabled may create and manage their own private subhierarchy of control groups below the control group of the unit itself. For unprivileged services (i.e. those using the User= setting) the unit's control group will be made accessible to the relevant user. When enabled the service manager will refrain from manipulating control groups or moving processes below the unit's control group, so that a clear concept of ownership is established: the control group tree above the unit's control group (i.e. towards the root control group) is owned and managed by the service manager of the host, while the control group tree below the unit's control group is owned and managed by the unit itself. Takes either a boolean argument or a list of control group controller names. If true, delegation is turned on, and all supported controllers are enabled for the unit, making them available to the unit's processes for management. If false, delegation is turned off entirely (and no additional controllers are enabled). If set to a list of controllers, delegation is turned on, and the specified controllers are enabled for the unit. Note that additional controllers than the ones specified might be made available as well, depending on configuration of the containing slice unit or other units contained in it. Note that assigning the empty string will enable delegation, but reset the list of controllers, all assignments prior to this will have no effect. Defaults to false. Note that controller delegation to less privileged code is only safe on the unified control group hierarchy. Accordingly, access to the specified controllers will not be granted to unprivileged services on the legacy hierarchy, even when requested. The following controller names may be specified: cpu, cpuacct, io, blkio, memory, devices, pids. Not all of these controllers are available on all kernels however, and some are specific to the unified hierarchy while others are specific to the legacy hierarchy. Also note that the kernel might support further controllers, which aren't covered here yet as delegation is either not supported at all for them or not defined cleanly.
2018-10-21 09:40:20 +00:00
Slice = "machine.slice";
Delegate = true;
# Hack: we don't want to kill systemd-nspawn, since we call
# "machinectl poweroff" in preStop to shut down the
# container cleanly. But systemd requires sending a signal
# (at least if we want remaining processes to be killed
# after the timeout). So send an ignored signal.
KillMode = "mixed";
KillSignal = "WINCH";
DevicePolicy = "closed";
DeviceAllow = map (d: "${d.node} ${d.modifier}") cfg.allowedDevices;
};
system = config.nixpkgs.localSystem.system;
bindMountOpts = { name, ... }: {
options = {
mountPoint = mkOption {
example = "/mnt/usb";
type = types.str;
2015-09-28 05:48:16 +00:00
description = "Mount point on the container file system.";
};
hostPath = mkOption {
default = null;
example = "/home/alice";
2015-09-28 05:48:16 +00:00
type = types.nullOr types.str;
description = "Location of the host path to be mounted.";
};
isReadOnly = mkOption {
default = true;
type = types.bool;
2015-09-28 05:48:16 +00:00
description = "Determine whether the mounted path will be accessed in read-only mode.";
};
};
config = {
mountPoint = mkDefault name;
};
};
allowedDeviceOpts = { ... }: {
options = {
node = mkOption {
example = "/dev/net/tun";
type = types.str;
description = "Path to device node";
};
modifier = mkOption {
example = "rw";
type = types.str;
description = ''
Device node access modifier. Takes a combination
<literal>r</literal> (read), <literal>w</literal> (write), and
<literal>m</literal> (mknod). See the
<literal>systemd.resource-control(5)</literal> man page for more
information.'';
};
};
};
mkBindFlag = d:
let flagPrefix = if d.isReadOnly then " --bind-ro=" else " --bind=";
mountstr = if d.hostPath != null then "${d.hostPath}:${d.mountPoint}" else "${d.mountPoint}";
in flagPrefix + mountstr ;
mkBindFlags = bs: concatMapStrings mkBindFlag (lib.attrValues bs);
networkOptions = {
hostBridge = mkOption {
type = types.nullOr types.string;
default = null;
example = "br0";
description = ''
Put the host-side of the veth-pair into the named bridge.
Only one of hostAddress* or hostBridge can be given.
'';
};
forwardPorts = mkOption {
type = types.listOf (types.submodule {
options = {
protocol = mkOption {
type = types.str;
default = "tcp";
description = "The protocol specifier for port forwarding between host and container";
};
hostPort = mkOption {
type = types.int;
description = "Source port of the external interface on host";
};
containerPort = mkOption {
type = types.nullOr types.int;
default = null;
description = "Target port of container";
};
};
});
default = [];
example = [ { protocol = "tcp"; hostPort = 8080; containerPort = 80; } ];
description = ''
List of forwarded ports from host to container. Each forwarded port
is specified by protocol, hostPort and containerPort. By default,
protocol is tcp and hostPort and containerPort are assumed to be
the same if containerPort is not explicitly given.
'';
};
hostAddress = mkOption {
type = types.nullOr types.str;
default = null;
example = "10.231.136.1";
description = ''
The IPv4 address assigned to the host interface.
(Not used when hostBridge is set.)
'';
};
hostAddress6 = mkOption {
type = types.nullOr types.string;
default = null;
example = "fc00::1";
description = ''
The IPv6 address assigned to the host interface.
(Not used when hostBridge is set.)
'';
};
localAddress = mkOption {
type = types.nullOr types.str;
default = null;
example = "10.231.136.2";
description = ''
The IPv4 address assigned to the interface in the container.
If a hostBridge is used, this should be given with netmask to access
the whole network. Otherwise the default netmask is /32 and routing is
set up from localAddress to hostAddress and back.
'';
};
localAddress6 = mkOption {
type = types.nullOr types.string;
default = null;
example = "fc00::2";
description = ''
The IPv6 address assigned to the interface in the container.
If a hostBridge is used, this should be given with netmask to access
the whole network. Otherwise the default netmask is /128 and routing is
set up from localAddress6 to hostAddress6 and back.
'';
};
};
dummyConfig =
{
extraVeths = {};
additionalCapabilities = [];
allowedDevices = [];
hostAddress = null;
hostAddress6 = null;
localAddress = null;
localAddress6 = null;
tmpfs = null;
};
in
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
{
options = {
boot.isContainer = mkOption {
type = types.bool;
default = false;
description = ''
Whether this NixOS machine is a lightweight container running
in another NixOS system.
'';
};
boot.enableContainers = mkOption {
type = types.bool;
default = !config.boot.isContainer;
description = ''
Whether to enable support for nixos containers.
'';
};
containers = mkOption {
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
type = types.attrsOf (types.submodule (
{ config, options, name, ... }:
{
options = {
config = mkOption {
description = ''
A specification of the desired configuration of this
container, as a NixOS module.
'';
type = lib.mkOptionType {
name = "Toplevel NixOS config";
merge = loc: defs: (import ../../lib/eval-config.nix {
inherit system;
modules =
let extraConfig =
{ boot.isContainer = true;
networking.hostName = mkDefault name;
networking.useDHCP = false;
assertions = [
{
assertion = config.privateNetwork -> stringLength name < 12;
message = ''
Container name `${name}` is too long: When `privateNetwork` is enabled, container names can
not be longer than 11 characters, because the container's interface name is derived from it.
This might be fixed in the future. See https://github.com/NixOS/nixpkgs/issues/38509
'';
}
];
};
in [ extraConfig ] ++ (map (x: x.value) defs);
prefix = [ "containers" name ];
}).config;
};
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
};
path = mkOption {
type = types.path;
example = "/nix/var/nix/profiles/containers/webserver";
description = ''
As an alternative to specifying
<option>config</option>, you can specify the path to
the evaluated NixOS system configuration, typically a
symlink to a system profile.
'';
};
additionalCapabilities = mkOption {
type = types.listOf types.str;
default = [];
example = [ "CAP_NET_ADMIN" "CAP_MKNOD" ];
description = ''
Grant additional capabilities to the container. See the
capabilities(7) and systemd-nspawn(1) man pages for more
information.
'';
};
enableTun = mkOption {
type = types.bool;
default = false;
description = ''
Allows the container to create and setup tunnel interfaces
by granting the <literal>NET_ADMIN</literal> capability and
enabling access to <literal>/dev/net/tun</literal>.
'';
};
privateNetwork = mkOption {
type = types.bool;
default = false;
description = ''
Whether to give the container its own private virtual
Ethernet interface. The interface is called
<literal>eth0</literal>, and is hooked up to the interface
<literal>ve-<replaceable>container-name</replaceable></literal>
on the host. If this option is not set, then the
container shares the network interfaces of the host,
and can bind to any port on any interface.
'';
};
interfaces = mkOption {
type = types.listOf types.string;
default = [];
example = [ "eth1" "eth2" ];
description = ''
The list of interfaces to be moved into the container.
'';
};
macvlans = mkOption {
type = types.listOf types.str;
default = [];
example = [ "eth1" "eth2" ];
description = ''
The list of host interfaces from which macvlans will be
created. For each interface specified, a macvlan interface
will be created and moved to the container.
'';
};
extraVeths = mkOption {
type = with types; attrsOf (submodule { options = networkOptions; });
default = {};
description = ''
Extra veth-pairs to be created for the container
'';
};
2015-01-12 17:12:33 +00:00
autoStart = mkOption {
type = types.bool;
default = false;
description = ''
2017-11-01 08:25:26 +00:00
Whether the container is automatically started at boot-time.
2015-01-12 17:12:33 +00:00
'';
};
2015-05-24 16:31:59 +00:00
bindMounts = mkOption {
type = with types; loaOf (submodule bindMountOpts);
default = {};
example = { "/home" = { hostPath = "/home/alice";
isReadOnly = false; };
};
2015-05-24 16:31:59 +00:00
description =
''
An extra list of directories that is bound to the container.
2015-05-24 16:31:59 +00:00
'';
};
allowedDevices = mkOption {
type = with types; listOf (submodule allowedDeviceOpts);
default = [];
example = [ { node = "/dev/net/tun"; modifier = "rw"; } ];
description = ''
A list of device nodes to which the containers has access to.
'';
};
tmpfs = mkOption {
type = types.listOf types.str;
default = [];
example = [ "/var" ];
description = ''
Mounts a set of tmpfs file systems into the container.
Multiple paths can be specified.
Valid items must conform to the --tmpfs argument
of systemd-nspawn. See systemd-nspawn(1) for details.
'';
};
extraFlags = mkOption {
type = types.listOf types.str;
default = [];
example = [ "--drop-capability=CAP_SYS_CHROOT" ];
description = ''
Extra flags passed to the systemd-nspawn command.
See systemd-nspawn(1) for details.
'';
};
} // networkOptions;
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
config = mkMerge
[
(mkIf options.config.isDefined {
path = config.config.system.build.toplevel;
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
})
];
}));
default = {};
example = literalExample
''
{ webserver =
{ path = "/nix/var/nix/profiles/webserver";
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
};
database =
{ config =
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
{ config, pkgs, ... }:
{ services.postgresql.enable = true;
services.postgresql.package = pkgs.postgresql_9_6;
system.stateVersion = "17.03";
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
};
};
}
'';
description = ''
A set of NixOS system configurations to be run as lightweight
containers. Each container appears as a service
<literal>container-<replaceable>name</replaceable></literal>
on the host system, allowing it to be started and stopped via
<command>systemctl</command>.
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
'';
};
};
config = mkIf (config.boot.enableContainers) (let
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
unit = {
description = "Container '%i'";
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
unitConfig.RequiresMountsFor = [ "/var/lib/containers/%i" ];
path = [ pkgs.iproute ];
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
environment.INSTANCE = "%i";
environment.root = "/var/lib/containers/%i";
preStart = preStartScript dummyConfig;
script = startScript dummyConfig;
postStart = postStartScript dummyConfig;
preStop =
''
pid="$(cat /run/containers/$INSTANCE.pid)"
if [ -n "$pid" ]; then
kill -RTMIN+4 "$pid"
fi
rm -f "/run/containers/$INSTANCE.pid"
'';
restartIfChanged = false;
serviceConfig = serviceDirectives dummyConfig;
};
in {
nixos/containers: Introduce several tweaks to systemd-nspawn from upstream systemd * Lets container@.service be activated by machines.target instead of multi-user.target According to the systemd manpages, all containers that are registered by machinectl, should be inside machines.target for easy stopping and starting container units altogether * make sure container@.service and container.slice instances are actually located in machine.slice https://plus.google.com/112206451048767236518/posts/SYAueyXHeEX See original commit: https://github.com/NixOS/systemd/commit/45d383a3b8 * Enable Cgroup delegation for nixos-containers Delegate=yes should be set for container scopes where a systemd instance inside the container shall manage the hierarchies below its own cgroup and have access to all controllers. This is equivalent to enabling all accounting options on the systemd process inside the system container. This means that systemd inside the container is responsible for managing Cgroup resources for unit files that enable accounting options inside. Without this option, units that make use of cgroup features within system containers might misbehave See original commit: https://github.com/NixOS/systemd/commit/a931ad47a8 from the manpage: Turns on delegation of further resource control partitioning to processes of the unit. Units where this is enabled may create and manage their own private subhierarchy of control groups below the control group of the unit itself. For unprivileged services (i.e. those using the User= setting) the unit's control group will be made accessible to the relevant user. When enabled the service manager will refrain from manipulating control groups or moving processes below the unit's control group, so that a clear concept of ownership is established: the control group tree above the unit's control group (i.e. towards the root control group) is owned and managed by the service manager of the host, while the control group tree below the unit's control group is owned and managed by the unit itself. Takes either a boolean argument or a list of control group controller names. If true, delegation is turned on, and all supported controllers are enabled for the unit, making them available to the unit's processes for management. If false, delegation is turned off entirely (and no additional controllers are enabled). If set to a list of controllers, delegation is turned on, and the specified controllers are enabled for the unit. Note that additional controllers than the ones specified might be made available as well, depending on configuration of the containing slice unit or other units contained in it. Note that assigning the empty string will enable delegation, but reset the list of controllers, all assignments prior to this will have no effect. Defaults to false. Note that controller delegation to less privileged code is only safe on the unified control group hierarchy. Accordingly, access to the specified controllers will not be granted to unprivileged services on the legacy hierarchy, even when requested. The following controller names may be specified: cpu, cpuacct, io, blkio, memory, devices, pids. Not all of these controllers are available on all kernels however, and some are specific to the unified hierarchy while others are specific to the legacy hierarchy. Also note that the kernel might support further controllers, which aren't covered here yet as delegation is either not supported at all for them or not defined cleanly.
2018-10-21 09:40:20 +00:00
systemd.targets."multi-user".wants = [ "machines.target" ];
systemd.services = listToAttrs (filter (x: x.value != null) (
# The generic container template used by imperative containers
[{ name = "container@"; value = unit; }]
# declarative containers
++ (mapAttrsToList (name: cfg: nameValuePair "container@${name}" (let
config = cfg // (
if cfg.enableTun then
{
allowedDevices = cfg.allowedDevices
++ [ { node = "/dev/net/tun"; modifier = "rw"; } ];
additionalCapabilities = cfg.additionalCapabilities
++ [ "CAP_NET_ADMIN" ];
}
else {});
in
unit // {
preStart = preStartScript config;
script = startScript config;
postStart = postStartScript config;
serviceConfig = serviceDirectives config;
} // (
if config.autoStart then
{
nixos/containers: Introduce several tweaks to systemd-nspawn from upstream systemd * Lets container@.service be activated by machines.target instead of multi-user.target According to the systemd manpages, all containers that are registered by machinectl, should be inside machines.target for easy stopping and starting container units altogether * make sure container@.service and container.slice instances are actually located in machine.slice https://plus.google.com/112206451048767236518/posts/SYAueyXHeEX See original commit: https://github.com/NixOS/systemd/commit/45d383a3b8 * Enable Cgroup delegation for nixos-containers Delegate=yes should be set for container scopes where a systemd instance inside the container shall manage the hierarchies below its own cgroup and have access to all controllers. This is equivalent to enabling all accounting options on the systemd process inside the system container. This means that systemd inside the container is responsible for managing Cgroup resources for unit files that enable accounting options inside. Without this option, units that make use of cgroup features within system containers might misbehave See original commit: https://github.com/NixOS/systemd/commit/a931ad47a8 from the manpage: Turns on delegation of further resource control partitioning to processes of the unit. Units where this is enabled may create and manage their own private subhierarchy of control groups below the control group of the unit itself. For unprivileged services (i.e. those using the User= setting) the unit's control group will be made accessible to the relevant user. When enabled the service manager will refrain from manipulating control groups or moving processes below the unit's control group, so that a clear concept of ownership is established: the control group tree above the unit's control group (i.e. towards the root control group) is owned and managed by the service manager of the host, while the control group tree below the unit's control group is owned and managed by the unit itself. Takes either a boolean argument or a list of control group controller names. If true, delegation is turned on, and all supported controllers are enabled for the unit, making them available to the unit's processes for management. If false, delegation is turned off entirely (and no additional controllers are enabled). If set to a list of controllers, delegation is turned on, and the specified controllers are enabled for the unit. Note that additional controllers than the ones specified might be made available as well, depending on configuration of the containing slice unit or other units contained in it. Note that assigning the empty string will enable delegation, but reset the list of controllers, all assignments prior to this will have no effect. Defaults to false. Note that controller delegation to less privileged code is only safe on the unified control group hierarchy. Accordingly, access to the specified controllers will not be granted to unprivileged services on the legacy hierarchy, even when requested. The following controller names may be specified: cpu, cpuacct, io, blkio, memory, devices, pids. Not all of these controllers are available on all kernels however, and some are specific to the unified hierarchy while others are specific to the legacy hierarchy. Also note that the kernel might support further controllers, which aren't covered here yet as delegation is either not supported at all for them or not defined cleanly.
2018-10-21 09:40:20 +00:00
wantedBy = [ "machines.target" ];
wants = [ "network.target" ];
after = [ "network.target" ];
restartTriggers = [ config.path ];
reloadIfChanged = true;
}
else {})
)) config.containers)
));
# Generate a configuration file in /etc/containers for each
# container so that container@.target can get the container
# configuration.
environment.etc =
let mkPortStr = p: p.protocol + ":" + (toString p.hostPort) + ":" + (if p.containerPort == null then toString p.hostPort else toString p.containerPort);
in mapAttrs' (name: cfg: nameValuePair "containers/${name}.conf"
{ text =
''
SYSTEM_PATH=${cfg.path}
${optionalString cfg.privateNetwork ''
PRIVATE_NETWORK=1
${optionalString (cfg.hostBridge != null) ''
HOST_BRIDGE=${cfg.hostBridge}
''}
${optionalString (length cfg.forwardPorts > 0) ''
HOST_PORT=${concatStringsSep "," (map mkPortStr cfg.forwardPorts)}
''}
${optionalString (cfg.hostAddress != null) ''
HOST_ADDRESS=${cfg.hostAddress}
''}
${optionalString (cfg.hostAddress6 != null) ''
HOST_ADDRESS6=${cfg.hostAddress6}
''}
${optionalString (cfg.localAddress != null) ''
LOCAL_ADDRESS=${cfg.localAddress}
''}
${optionalString (cfg.localAddress6 != null) ''
LOCAL_ADDRESS6=${cfg.localAddress6}
''}
''}
INTERFACES="${toString cfg.interfaces}"
MACVLANS="${toString cfg.macvlans}"
${optionalString cfg.autoStart ''
AUTO_START=1
''}
EXTRA_NSPAWN_FLAGS="${mkBindFlags cfg.bindMounts +
optionalString (cfg.extraFlags != [])
(" " + concatStringsSep " " cfg.extraFlags)}"
'';
}) config.containers;
Add support for lightweight NixOS containers You can now say: systemd.containers.foo.config = { services.openssh.enable = true; services.openssh.ports = [ 2022 ]; users.extraUsers.root.openssh.authorizedKeys.keys = [ "ssh-dss ..." ]; }; which defines a NixOS instance with the given configuration running inside a lightweight container. You can also manage the configuration of the container independently from the host: systemd.containers.foo.path = "/nix/var/nix/profiles/containers/foo"; where "path" is a NixOS system profile. It can be created/updated by doing: $ nix-env --set -p /nix/var/nix/profiles/containers/foo \ -f '<nixos>' -A system -I nixos-config=foo.nix The container configuration (foo.nix) should define boot.isContainer = true; to optimise away the building of a kernel and initrd. This is done automatically when using the "config" route. On the host, a lightweight container appears as the service "container-<name>.service". The container is like a regular NixOS (virtual) machine, except that it doesn't have its own kernel. It has its own root file system (by default /var/lib/containers/<name>), but shares the Nix store of the host (as a read-only bind mount). It also has access to the network devices of the host. Currently, if the configuration of the container changes, running "nixos-rebuild switch" on the host will cause the container to be rebooted. In the future we may want to send some message to the container so that it can activate the new container configuration without rebooting. Containers are not perfectly isolated yet. In particular, the host's /sys/fs/cgroup is mounted (writable!) in the guest.
2013-11-27 15:54:20 +00:00
# Generate /etc/hosts entries for the containers.
networking.extraHosts = concatStrings (mapAttrsToList (name: cfg: optionalString (cfg.localAddress != null)
''
${head (splitString "/" cfg.localAddress)} ${name}.containers
'') config.containers);
networking.dhcpcd.denyInterfaces = [ "ve-*" "vb-*" ];
services.udev.extraRules = optionalString config.networking.networkmanager.enable ''
# Don't manage interfaces created by nixos-container.
ENV{INTERFACE}=="v[eb]-*", ENV{NM_UNMANAGED}="1"
'';
environment.systemPackages = [ pkgs.nixos-container ];
});
}