[WIP] Mail infrastructure

modules/accounts/email.nix

@@ -0,0 +1,323 @@
+{ config, lib, ... }:
+
+with lib;
+
+let
+
+  cfg = config.accounts.email;
+
+  tlsModule = types.submodule {
+    options = {
+      enable = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Whether to enable TLS/SSL.
+        '';
+      };
+
+      useStartTls = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether to use STARTTLS.
+        '';
+      };
+
+      certificatesFile = mkOption {
+        type = types.nullOr types.path;
+        default = null;
+        description = ''
+          Path to file containing certificate authorities that should
+          be used to validate the connection authenticity. If
+          <literal>null</literal> then the system default is used.
+          Note, if set then the system default may still be accepted.
+        '';
+      };
+    };
+  };
+
+  imapModule = types.submodule {
+    options = {
+      host = mkOption {
+        type = types.str;
+        example = "imap.example.org";
+        description = ''
+          Hostname of IMAP server.
+        '';
+      };
+
+      port = mkOption {
+        type = types.nullOr types.ints.positive;
+        default = null;
+        example = 993;
+        description = ''
+          The port on which the IMAP server listens. If
+          <literal>null</literal> then the default port is used.
+        '';
+      };
+
+      tls = mkOption {
+        type = tlsModule;
+        default = {};
+        description = ''
+          Configuration for secure connections.
+        '';
+      };
+    };
+  };
+
+  smtpModule = types.submodule {
+    options = {
+      host = mkOption {
+        type = types.str;
+        example = "smtp.example.org";
+        description = ''
+          Hostname of SMTP server.
+        '';
+      };
+
+      port = mkOption {
+        type = types.nullOr types.ints.positive;
+        default = null;
+        example = 465;
+        description = ''
+          The port on which the SMTP server listens. If
+          <literal>null</literal> then the default port is used.
+        '';
+      };
+
+      tls = mkOption {
+        type = tlsModule;
+        default = {};
+        description = ''
+          Configuration for secure connections.
+        '';
+      };
+    };
+  };
+
+  maildirModule = types.submodule ({ config, ... }: {
+    options = {
+      path = mkOption {
+        type = types.str;
+        description = ''
+          Path to maildir directory where mail for this account is
+          stored. This is relative to the base maildir path.
+        '';
+      };
+
+      absPath = mkOption {
+        type = types.path;
+        readOnly = true;
+        internal = true;
+        default = "${cfg.maildirBasePath}/${config.path}";
+        description = ''
+          A convenience option whose value is the absolute path of
+          this maildir.
+        '';
+      };
+    };
+  });
+
+  # gpgModule = types.submodule {
+  # };
+
+  mailAccount = types.submodule ({ name, config, ... }: {
+    options = {
+      name = mkOption {
+        type = types.str;
+        readOnly = true;
+        description = ''
+          Unique identifier of the account. This is set to the
+          attribute name of the account configuration.
+        '';
+      };
+
+      primary = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether this is the primary account. Only one account may be
+          set as primary.
+        '';
+      };
+
+      flavor = mkOption {
+        type = types.enum [ "plain" "runbox.com" ];
+        default = "plain";
+        description = ''
+          Some email providers have peculiar behavior that require
+          special treatment. This option is therefore intended to
+          indicate the nature of the provider.
+          </para><para>
+          When this indicates a specific provider then, for example,
+          the IMAP and SMTP server configuration may be set
+          automatically.
+        '';
+      };
+
+      address = mkOption {
+        type = types.strMatching ".*@.*";
+        example = "jane.doe@example.org";
+        description = "The email address of this account.";
+      };
+
+      realName = mkOption {
+        type = types.str;
+        example = "Jane Doe";
+        description = "Name displayed when sending mails.";
+      };
+
+      userName = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          The server username of this account. This will be used as
+          the SMTP and IMAP user name.
+        '';
+      };
+
+      passwordCommand = mkOption {
+        type = types.nullOr (types.either types.str (types.listOf types.str));
+        default = null;
+        apply = p: if isString p then splitString " " p else p;
+        example = "secret-tool lookup email me@example.org";
+        description = ''
+          A command, which when run writes the account password on
+          standard output.
+        '';
+      };
+
+      folders = mkOption {
+        type = types.submodule {
+          options = {
+            inbox = mkOption {
+              type = types.str;
+              default = "Inbox";
+              description = ''
+                Relative path of the inbox mail.
+              '';
+            };
+
+            sent = mkOption {
+              type = types.nullOr types.str;
+              default = "Sent";
+              description = ''
+                Relative path of the sent mail folder.
+              '';
+            };
+
+            drafts = mkOption {
+              type = types.str;
+              default = "Drafts";
+              description = ''
+                Relative path of the drafts mail folder.
+              '';
+            };
+
+            trash = mkOption {
+              type = types.str;
+              default = "Trash";
+              description = ''
+                Relative path of the deleted mail folder.
+              '';
+            };
+          };
+        };
+        default = {};
+        description = ''
+          Standard email folders.
+        '';
+      };
+
+      imap = mkOption {
+        type = types.nullOr imapModule;
+        default = null;
+        description = ''
+          The IMAP configuration to use for this account.
+        '';
+      };
+
+      smtp = mkOption {
+        type = types.nullOr smtpModule;
+        default = null;
+        description = ''
+          The SMTP configuration to use for this account.
+        '';
+      };
+
+      maildir = mkOption {
+        type = types.nullOr maildirModule;
+        defaultText = { path = "\${name}"; };
+        description = ''
+          Maildir configuration for this account.
+        '';
+      };
+    };
+
+    config = mkMerge [
+      {
+        name = name;
+        maildir = mkOptionDefault { path = "${name}"; };
+      }
+
+      (mkIf (config.flavor == "runbox.com") {
+        imap = {
+          host = "mail.runbox.com";
+        };
+
+        smtp = {
+          host = "mail.runbox.com";
+        };
+      })
+    ];
+  });
+
+in
+
+{
+  options.accounts.email = {
+    maildirBasePath = mkOption {
+      type = types.str;
+      default = "${config.home.homeDirectory}/Maildir";
+      defaultText = "$HOME/Maildir";
+      apply = p:
+        if hasPrefix "/" p
+        then p
+        else "${config.home.homeDirectory}/${p}";
+      description = ''
+        The base directory for account maildir directories. May be a
+        relative path, in which case it is relative the home
+        directory.
+      '';
+    };
+
+    accounts = mkOption {
+      type = types.attrsOf mailAccount;
+      default = {};
+      description = "List of email accounts.";
+    };
+  };
+
+  config = mkIf (cfg.accounts != {}) {
+    assertions = [
+      (
+        let
+          primaries =
+            catAttrs "name"
+            (filter (a: a.primary)
+            (attrValues cfg.accounts));
+        in
+          {
+            assertion = length primaries == 1;
+            message =
+              "Must have exactly one primary mail account but found "
+              + toString (length primaries)
+              + optionalString (length primaries > 1)
+                  (", namely " + concatStringsSep ", " primaries);
+          }
+      )
+    ];
+  };
+}

modules/misc/news.nix

@@ -672,6 +672,45 @@ in
         '';
       }
 
+      {
+        time = "2018-07-01T14:33:15+00:00";
+        message = ''
+          A new module is available: 'accounts.email'.
+
+          As the name suggests, this new module offers a number of
+          options for configuring email accounts. This, for example,
+          includes the email address and owner's real name but also
+          server settings for IMAP and SMTP.
+
+          The intent is to have a central location for account
+          specific configuration that other modules can use.
+
+          Note, this module is still somewhat experimental and its
+          structure should not be seen as final. Feedback is greatly
+          appreciated, both positive and negative.
+        '';
+      }
+
+      {
+        time = "2018-07-01T16:07:04+00:00";
+        message = ''
+          A new module is available: 'programs.mbsync'.
+        '';
+      }
+
+      {
+        time = "2018-07-01T16:12:20+00:00";
+        message = ''
+          A new module is available: 'programs.notmuch'.
+        '';
+      }
+
+      {
+        time = "2018-06-10T20:33:16+00:00";
+        message = ''
+          A new module is available: `programs.neomutt`.
+        '';
+      }
     ];
   };
 }

modules/modules.nix

@@ -13,6 +13,7 @@ with lib;
 let
 
   modules = [
+    ./accounts/email.nix
     ./files.nix
     ./home-environment.nix
     ./manual.nix
@@ -40,9 +41,12 @@ let
     ./programs/info.nix
     ./programs/lesspipe.nix
     ./programs/man.nix
+    ./programs/mbsync.nix
     ./programs/mercurial.nix
+    ./programs/neomutt.nix
     ./programs/neovim.nix
     ./programs/newsboat.nix
+    ./programs/notmuch.nix
     ./programs/pidgin.nix
     ./programs/rofi.nix
     ./programs/ssh.nix