nixpkgs/nixos/modules/services/networking/iscsi/root-initiator.nix
ajs124 47598c476a nixos/iscsi/root-initiator: init
Co-authored-by: Graham Christensen <graham@floxdev.com>
2021-04-06 18:34:32 +00:00

182 lines
5.8 KiB
Nix

{ config, lib, pkgs, ... }: with lib;
let
cfg = config.boot.iscsi-initiator;
in
{
# If you're booting entirely off another machine you may want to add
# this snippet to always boot the latest "system" version. It is not
# enabled by default in case you have an initrd on a local disk:
#
# boot.initrd.postMountCommands = ''
# ln -sfn /nix/var/nix/profiles/system/init /mnt-root/init
# stage2Init=/init
# '';
#
# Note: Theoretically you might want to connect to multiple portals and
# log in to multiple targets, however the authors of this module so far
# don't have the need or expertise to reasonably implement it. Also,
# consider carefully before making your boot chain depend on multiple
# machines to be up.
options.boot.iscsi-initiator = with types; {
name = mkOption {
description = ''
Name of the iSCSI initiator to boot from. Note, booting from iscsi
requires networkd based networking.
'';
default = null;
example = "iqn.2020-08.org.linux-iscsi.initiatorhost:example";
type = nullOr str;
};
discoverPortal = mkOption {
description = ''
iSCSI portal to boot from.
'';
default = null;
example = "192.168.1.1:3260";
type = nullOr str;
};
target = mkOption {
description = ''
Name of the iSCSI target to boot from.
'';
default = null;
example = "iqn.2020-08.org.linux-iscsi.targethost:example";
type = nullOr str;
};
logLevel = mkOption {
description = ''
Higher numbers elicits more logs.
'';
default = 1;
example = 8;
type = int;
};
loginAll = mkOption {
description = ''
Do not log into a specific target on the portal, but to all that we discover.
This overrides setting target.
'';
type = bool;
default = false;
};
extraConfig = mkOption {
description = "Extra lines to append to /etc/iscsid.conf";
default = null;
type = nullOr lines;
};
extraConfigFile = mkOption {
description = ''
Append an additional file's contents to `/etc/iscsid.conf`. Use a non-store path
and store passwords in this file. Note: the file specified here must be available
in the initrd, see: `boot.initrd.secrets`.
'';
default = null;
type = nullOr str;
};
};
config = mkIf (cfg.name != null) {
# The "scripted" networking configuration (ie: non-networkd)
# doesn't properly order the start and stop of the interfaces, and the
# network interfaces are torn down before unmounting disks. Since this
# module is specifically for very-early-boot network mounts, we need
# the network to stay on.
#
# We could probably fix the scripted options to properly order, but I'm
# not inclined to invest that time today. Hopefully this gets users far
# enough along and they can just use networkd.
networking.useNetworkd = true;
networking.useDHCP = false; # Required to set useNetworkd = true
boot.initrd = {
network.enable = true;
# By default, the stage-1 disables the network and resets the interfaces
# on startup. Since our startup disks are on the network, we can't let
# the network not work.
network.flushBeforeStage2 = false;
kernelModules = [ "iscsi_tcp" ];
extraUtilsCommands = ''
copy_bin_and_libs ${pkgs.openiscsi}/bin/iscsid
copy_bin_and_libs ${pkgs.openiscsi}/bin/iscsiadm
${optionalString (!config.boot.initrd.network.ssh.enable) "cp -pv ${pkgs.glibc.out}/lib/libnss_files.so.* $out/lib"}
mkdir -p $out/etc/iscsi
cp ${config.environment.etc.hosts.source} $out/etc/hosts
cp ${pkgs.openiscsi}/etc/iscsi/iscsid.conf $out/etc/iscsi/iscsid.fragment.conf
chmod +w $out/etc/iscsi/iscsid.fragment.conf
cat << 'EOF' >> $out/etc/iscsi/iscsid.fragment.conf
${optionalString (cfg.extraConfig != null) cfg.extraConfig}
EOF
'';
extraUtilsCommandsTest = ''
$out/bin/iscsiadm --version
'';
preLVMCommands = let
extraCfgDumper = optionalString (cfg.extraConfigFile != null) ''
if [ -f "${cfg.extraConfigFile}" ]; then
printf "\n# The following is from ${cfg.extraConfigFile}:\n"
cat "${cfg.extraConfigFile}"
else
echo "Warning: boot.iscsi-initiator.extraConfigFile ${cfg.extraConfigFile} does not exist!" >&2
fi
'';
in ''
${optionalString (!config.boot.initrd.network.ssh.enable) ''
# stolen from initrd-ssh.nix
echo 'root:x:0:0:root:/root:/bin/ash' > /etc/passwd
echo 'passwd: files' > /etc/nsswitch.conf
''}
cp -f $extraUtils/etc/hosts /etc/hosts
mkdir -p /etc/iscsi /run/lock/iscsi
echo "InitiatorName=${cfg.name}" > /etc/iscsi/initiatorname.iscsi
(
cat "$extraUtils/etc/iscsi/iscsid.fragment.conf"
printf "\n"
${optionalString cfg.loginAll ''echo "node.startup = automatic"''}
${extraCfgDumper}
) > /etc/iscsi/iscsid.conf
iscsid --foreground --no-pid-file --debug ${toString cfg.logLevel} &
iscsiadm --mode discoverydb \
--type sendtargets \
--discover \
--portal ${escapeShellArg cfg.discoverPortal} \
--debug ${toString cfg.logLevel}
${if cfg.loginAll then ''
iscsiadm --mode node --loginall all
'' else ''
iscsiadm --mode node --targetname ${escapeShellArg cfg.target} --login
''}
pkill -9 iscsid
'';
};
services.openiscsi = {
enable = true;
inherit (cfg) name;
};
assertions = [
{
assertion = cfg.loginAll -> cfg.target == null;
message = "iSCSI target name is set while login on all portals is enabled.";
}
];
};
}