nixpkgs/nixos/modules/virtualisation/railcar.nix
2021-10-04 12:47:20 +02:00

125 lines
3.5 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.railcar;
generateUnit = name: containerConfig:
let
container = pkgs.ociTools.buildContainer {
args = [
(pkgs.writeShellScript "run.sh" containerConfig.cmd).outPath
];
};
in
nameValuePair "railcar-${name}" {
enable = true;
wantedBy = [ "multi-user.target" ];
serviceConfig = {
ExecStart = ''
${cfg.package}/bin/railcar -r ${cfg.stateDir} run ${name} -b ${container}
'';
Type = containerConfig.runType;
};
};
mount = with types; (submodule {
options = {
type = mkOption {
type = str;
default = "none";
description = ''
The type of the filesystem to be mounted.
Linux: filesystem types supported by the kernel as listed in
`/proc/filesystems` (e.g., "minix", "ext2", "ext3", "jfs", "xfs",
"reiserfs", "msdos", "proc", "nfs", "iso9660"). For bind mounts
(when options include either bind or rbind), the type is a dummy,
often "none" (not listed in /proc/filesystems).
'';
};
source = mkOption {
type = str;
description = "Source for the in-container mount";
};
options = mkOption {
type = listOf str;
default = [ "bind" ];
description = ''
Mount options of the filesystem to be used.
Support options are listed in the mount(8) man page. Note that
both filesystem-independent and filesystem-specific options
are listed.
'';
};
};
});
in
{
options.services.railcar = {
enable = mkEnableOption "railcar";
containers = mkOption {
default = {};
description = "Declarative container configuration";
type = with types; attrsOf (submodule ({ name, config, ... }: {
options = {
cmd = mkOption {
type = types.lines;
description = "Command or script to run inside the container";
};
mounts = mkOption {
type = with types; attrsOf mount;
default = {};
description = ''
A set of mounts inside the container.
The defaults have been chosen for simple bindmounts, meaning
that you only need to provide the "source" parameter.
'';
example = { "/data" = { source = "/var/lib/data"; }; };
};
runType = mkOption {
type = types.str;
default = "oneshot";
description = "The systemd service run type";
};
os = mkOption {
type = types.str;
default = "linux";
description = "OS type of the container";
};
arch = mkOption {
type = types.str;
default = "x86_64";
description = "Computer architecture type of the container";
};
};
}));
};
stateDir = mkOption {
type = types.path;
default = "/var/railcar";
description = "Railcar persistent state directory";
};
package = mkOption {
type = types.package;
default = pkgs.railcar;
defaultText = literalExpression "pkgs.railcar";
description = "Railcar package to use";
};
};
config = mkIf cfg.enable {
systemd.services = flip mapAttrs' cfg.containers (name: containerConfig:
generateUnit name containerConfig
);
};
}