nixos/nvme: Add module

nixos/modules/nvme/default.nix

@@ -0,0 +1,58 @@
+{ lib, pkgs, config, ... }:
+let
+  inherit (lib) mkIf;
+  inherit (lib.my) mkOpt';
+
+  cfg = config.my.nvme;
+  nvme-cli = pkgs.nvme-cli.override {
+    libnvme = pkgs.libnvme.overrideAttrs (o: {
+      patches = o.patches ++ [ ./libnvme-hostconf.patch ];
+    });
+  };
+
+  hostNQN = "nqn.2014-08.org.nvmexpress:uuid:${cfg.uuid}";
+  etc = prefix: {
+    "${prefix}nvme/hostnqn".text = hostNQN;
+    "${prefix}nvme/hostid".text = cfg.uuid;
+  };
+in
+{
+  options.my.nvme = with lib.types; {
+    uuid = mkOpt' (nullOr str) null "NVMe host ID";
+    boot = {
+      nqn = mkOpt' (nullOr str) null "NQN to connect to on boot";
+      address = mkOpt' str null "Address of NVMe-oF target.";
+    };
+  };
+
+  config = mkIf (cfg.uuid != null) {
+    environment = {
+      systemPackages = [
+        nvme-cli
+      ];
+      etc = etc "";
+    };
+
+    boot.initrd.systemd = mkIf (cfg.boot.nqn != null) {
+      contents = etc "/etc/";
+      extraBin.nvme = "${nvme-cli}/bin/nvme";
+
+      services.connect-nvme = {
+        description = "Connect NVMe-oF";
+        before = [ "initrd-root-device.target" ];
+        after = [ "systemd-networkd-wait-online.service" ];
+        requires = [ "systemd-networkd-wait-online.service" ];
+
+        serviceConfig = {
+          Type = "oneshot";
+          ExecStart = "${nvme-cli}/bin/nvme connect -t rdma -a ${cfg.boot.address} -n ${cfg.boot.nqn}";
+          Restart = "on-failure";
+          RestartSec = 10;
+        };
+
+        wantedBy = [ "initrd-root-device.target" ];
+      };
+    };
+  };
+}
+