nixos/iscsi/initiator: init

Co-authored-by: Graham Christensen <graham@floxdev.com>

nixos/modules/module-list.nix

@@ -691,6 +691,7 @@
   ./services/networking/iodine.nix
   ./services/networking/iperf3.nix
   ./services/networking/ircd-hybrid/default.nix
+  ./services/networking/iscsi/initiator.nix
   ./services/networking/iscsi/target.nix
   ./services/networking/iwd.nix
   ./services/networking/jicofo.nix

nixos/modules/services/networking/iscsi/initiator.nix

@@ -0,0 +1,84 @@
+{ config, lib, pkgs, ... }: with lib;
+let
+  cfg = config.services.openiscsi;
+in
+{
+  options.services.openiscsi = with types; {
+    enable = mkEnableOption "the openiscsi iscsi daemon";
+    enableAutoLoginOut = mkEnableOption ''
+      automatic login and logout of all automatic targets.
+      You probably do not want this.
+    '';
+    discoverPortal = mkOption {
+      type = nullOr str;
+      default = null;
+      description = "Portal to discover targets on";
+    };
+    name = mkOption {
+      type = str;
+      description = "Name of this iscsi initiator";
+      example = "iqn.2020-08.org.linux-iscsi.initiatorhost:example";
+    };
+    package = mkOption {
+      type = package;
+      description = "openiscsi package to use";
+      default = pkgs.openiscsi;
+      defaultText = "pkgs.openiscsi";
+    };
+
+    extraConfig = mkOption {
+      type = str;
+      default = "";
+      description = "Lines to append to default iscsid.conf";
+    };
+
+    extraConfigFile = mkOption {
+      description = ''
+        Append an additional file's contents to /etc/iscsid.conf. Use a non-store path
+        and store passwords in this file.
+      '';
+      default = null;
+      type = nullOr str;
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment.etc."iscsi/iscsid.conf.fragment".source = pkgs.runCommand "iscsid.conf" {} ''
+      cat "${cfg.package}/etc/iscsi/iscsid.conf" > $out
+      cat << 'EOF' >> $out
+      ${cfg.extraConfig}
+      ${optionalString cfg.enableAutoLoginOut "node.startup = automatic"}
+      EOF
+    '';
+    environment.etc."iscsi/initiatorname.iscsi".text = "InitiatorName=${cfg.name}";
+
+    system.activationScripts.iscsid = 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: services.openiscsi.extraConfigFile ${cfg.extraConfigFile} does not exist!" >&2
+        fi
+      '';
+    in ''
+      (
+        cat ${config.environment.etc."iscsi/iscsid.conf.fragment".source}
+        ${extraCfgDumper}
+      ) > /etc/iscsi/iscsid.conf
+    '';
+
+    systemd.packages = [ cfg.package ];
+
+    systemd.services."iscsid".wantedBy = [ "multi-user.target" ];
+    systemd.sockets."iscsid".wantedBy = [ "sockets.target" ];
+
+    systemd.services."iscsi" = mkIf cfg.enableAutoLoginOut {
+      wantedBy = [ "remote-fs.target" ];
+      serviceConfig.ExecStartPre = mkIf (cfg.discoverPortal != null) "${cfg.package}/bin/iscsiadm --mode discoverydb --type sendtargets --portal ${escapeShellArg cfg.discoverPortal} --discover";
+    };
+
+    environment.systemPackages = [ cfg.package ];
+    boot.kernelModules = [ "iscsi_tcp" ];
+  };
+}