sftpman: add module

modules/programs/sftpman.nix

@@ -0,0 +1,118 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.programs.sftpman;
+
+  jsonFormat = pkgs.formats.json { };
+
+  mountOpts = { config, name, ... }: {
+    options = {
+      host = mkOption {
+        type = types.str;
+        description = "The host to connect to.";
+      };
+
+      port = mkOption {
+        type = types.port;
+        default = 22;
+        description = "The port to connect to.";
+      };
+
+      user = mkOption {
+        type = types.str;
+        description = "The username to authenticate with.";
+      };
+
+      mountOptions = mkOption {
+        type = types.listOf types.str;
+        default = [ ];
+        description = "Options to pass to sshfs.";
+      };
+
+      mountPoint = mkOption {
+        type = types.str;
+        description = "The remote path to mount.";
+      };
+
+      authType = mkOption {
+        type = types.enum [
+          "password"
+          "publickey"
+          "hostbased"
+          "keyboard-interactive"
+          "gssapi-with-mic"
+        ];
+        default = "publickey";
+        description = "The authentication method to use.";
+      };
+
+      sshKey = mkOption {
+        type = types.nullOr types.str;
+        default = cfg.defaultSshKey;
+        defaultText =
+          lib.literalExpression "config.programs.sftpman.defaultSshKey";
+        description = ''
+          Path to the SSH key to use for authentication.
+          Only applies if authMethod is `publickey`.
+        '';
+      };
+
+      beforeMount = mkOption {
+        type = types.str;
+        default = "true";
+        description = "Command to run before mounting.";
+      };
+    };
+  };
+in {
+  meta.maintainers = with maintainers; [ fugi ];
+
+  options.programs.sftpman = {
+    enable = mkEnableOption
+      "sftpman, an application that handles sshfs/sftp file systems mounting";
+
+    package = mkPackageOption pkgs "sftpman" { };
+
+    defaultSshKey = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description =
+        "Path to the SSH key to be used by default. Can be overridden per host.";
+    };
+
+    mounts = mkOption {
+      type = types.attrsOf (types.submodule mountOpts);
+      default = { };
+      description = ''
+        The sshfs mount configurations written to
+        {file}`$XDG_CONFIG_HOME/sftpman/mounts/`.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    assertions = [
+      (let
+        hasMissingKey = _: mount:
+          mount.authType == "publickey" && mount.sshKey == null;
+        mountsWithMissingKey = attrNames (filterAttrs hasMissingKey cfg.mounts);
+        mountsWithMissingKeyStr = concatStringsSep ", " mountsWithMissingKey;
+      in {
+        assertion = mountsWithMissingKey == [ ];
+        message = ''
+          sftpman mounts using authentication type "publickey" but missing 'sshKey': ${mountsWithMissingKeyStr}
+        '';
+      })
+    ];
+
+    home.packages = [ cfg.package ];
+
+    xdg.configFile = mapAttrs' (name: value:
+      nameValuePair "sftpman/mounts/${name}.json" {
+        source =
+          jsonFormat.generate "sftpman-${name}.json" (value // { id = name; });
+      }) cfg.mounts;
+  };
+}