nixos/systemd: Handle template overrides

Adding template overrides allows for custom behavior for specific
instances of a template. Previously, it was not possible to provide
bind mounts for systemd-nspawn. This change allows it.
This commit is contained in:
Adrian Parvin D. Ouano 2021-03-09 23:04:58 +08:00
parent 102eb68cee
commit e3b90b6ccc
2 changed files with 53 additions and 1 deletions

View file

@ -182,7 +182,18 @@ in rec {
# upstream unit.
for i in ${toString (mapAttrsToList (n: v: v.unit) units)}; do
fn=$(basename $i/*)
if [ -e $out/$fn ]; then
case $fn in
# if file name is a template specialization, use the template's name
*@?*.service)
# remove @foo.service and replace it with @.service
ofn="''${fn%@*.service}@.service"
;;
*)
ofn="$fn"
esac
if [ -e $out/$ofn ]; then
if [ "$(readlink -f $i/$fn)" = /dev/null ]; then
ln -sfn /dev/null $out/$fn
else

View file

@ -0,0 +1,41 @@
import ./make-test-python.nix {
name = "systemd-template-override";
machine = { pkgs, lib, ... }: let
touchTmp = pkgs.writeTextFile {
name = "touch-tmp@.service";
text = ''
[Service]
Type=oneshot
ExecStart=${pkgs.coreutils}/bin/touch /tmp/%I
'';
destination = "/etc/systemd/system/touch-tmp@.service";
};
in {
systemd.packages = [ touchTmp ];
systemd.services."touch-tmp@forbidden" = {
serviceConfig.ExecStart = [ "" ''
${pkgs.coreutils}/bin/true
''];
};
systemd.services."touch-tmp@intercept" = {
serviceConfig.ExecStart = [ "" ''
${pkgs.coreutils}/bin/touch /tmp/renamed
''];
};
};
testScript = ''
machine.wait_for_unit("default.target")
machine.succeed("systemctl start touch-tmp@normal")
machine.succeed("systemctl start touch-tmp@forbbidden")
machine.succeed("systemctl start touch-tmp@intercept")
machine.succeed("[ -e /tmp/normal ]")
machine.succeed("[ ! -e /tmp/forbidden ]")
machine.succeed("[ -e /tmp/renamed ]")
'';
}