Merge branch 'session-var-cleanup'

README.md

@@ -89,6 +89,24 @@ Currently the easiest way to install Home Manager is as follows:
     Home Manager should now be active and available in your user
     environment.
 
+5.  If you do not plan on having Home Manager manage your shell
+    configuration then you must source the
+
+    ```
+    "$HOME/.nix-profile/etc/profile.d/hm-session-vars.sh"
+    ```
+
+    file in your shell configuration. Unfortunately, we currently only
+    support POSIX.2-like shells such as [Bash][] or [Z shell][].
+
+    For example, if you use Bash then add
+
+    ```bash
+    . "$HOME/.nix-profile/etc/profile.d/hm-session-vars.sh"
+    ```
+
+    to your `~/.profile` file.
+
 Note, because the `HM_PATH` variable above points to the live Home
 Manager repository you will automatically get updates whenever you
 build a new generation. If you dislike automatic updates then perform
@@ -240,8 +258,10 @@ in your system configuration and
 
 in your Home Manager configuration.
 
+[Bash]: https://www.gnu.org/software/bash/
 [Nix]: https://nixos.org/nix/
 [NixOS]: https://nixos.org/
 [Nixpkgs]: https://nixos.org/nixpkgs/
 [nixAllowedUsers]: https://nixos.org/nix/manual/#conf-allowed-users
 [nixosAllowedUsers]: https://nixos.org/nixos/manual/options.html#opt-nix.allowedUsers
+[Z shell]: http://zsh.sourceforge.net/

modules/home-environment.nix

@@ -127,12 +127,40 @@ in
       example = { EDITOR = "emacs"; GS_OPTIONS = "-sPAPERSIZE=a4"; };
       description = ''
         Environment variables to always set at login.
+        </para><para>
+        The values may refer to other environment variables using
+        POSIX.2 style variable references. For example, a variable
+        <varname>parameter</varname> may be referenced as
+        <code>$parameter</code> or <code>''${parameter}</code>. A
+        default value <literal>foo</literal> may be given as per
+        <code>''${parameter:-foo}</code> and, similarly, an alternate
+        value <literal>bar</literal> can be given as per
+        <code>''${parameter:+bar}</code>.
+        </para><para>
+        Note, these variables may be set in any order so no session
+        variable may have a runtime dependency on another session
+        variable. In particular code like
+        <programlisting>
+          home.sessionVariables = {
+            FOO = "Hello";
+            BAR = "$FOO World!";
+          };
+        </programlisting>
+        may not work as expected. If you need to reference another
+        session variable, then do so inside Nix instead. The above
+        example then becomes
+        <programlisting>
+          home.sessionVariables = {
+            FOO = "Hello";
+            BAR = "''${config.home.sessionVariables.FOO} World!";
+          };
+        </programlisting>
       '';
     };
 
     home.sessionVariableSetter = mkOption {
-      default = "bash";
+      default = null;
-      type = types.enum [ "pam" "bash" "zsh" ];
+      type = types.nullOr (types.enum [ "pam" "bash" "zsh" ]);
       example = "pam";
       description = ''
         Identifies the module that should set the session variables.
@@ -143,6 +171,9 @@ in
         If "pam" is set then PAM must be used to set the system
         environment. Also mind that typical environment variables
         might not be set by the time PAM starts up.
+        </para><para>
+        This option is DEPRECATED, the shell modules are now
+        automatically setting the session variables when enabled.
       '';
     };
 
@@ -239,6 +270,23 @@ in
         //
         (maybeSet "LC_TIME" cfg.language.time);
 
+    home.packages = [
+      # Provide a file holding all session variables.
+      (
+        pkgs.writeTextFile {
+          name = "hm-session-vars.sh";
+          destination = "/etc/profile.d/hm-session-vars.sh";
+          text = ''
+            # Only source this once.
+            if [ -n "$__HM_SESS_VARS_SOURCED" ]; then return; fi
+            export __HM_SESS_VARS_SOURCED=1
+
+            ${config.lib.shell.exportAll cfg.sessionVariables}
+          '';
+        }
+      )
+    ];
+
     # A dummy entry acting as a boundary between the activation
     # script's "check" and the "write" phases.
     home.activation.writeBoundary = dag.entryAnywhere "";

modules/lib/default.nix

@@ -15,4 +15,6 @@
         entryAfter = d.dagEntryAfter;
         entryBefore = d.dagEntryBefore;
       };
+
+  shell = import ./shell.nix { inherit lib; };
 }

modules/lib/shell.nix

@@ -0,0 +1,11 @@
+{ lib }:
+
+rec {
+  # Produces a Bourne shell like variable export statement.
+  export = n: v: "export ${n}=\"${toString v}\"";
+
+  # Given an attribute set containing shell variable names and their
+  # assignment, this function produces a string containing an export
+  # statement for each set entry.
+  exportAll = vars: lib.concatStringsSep "\n" (lib.mapAttrsToList export vars);
+}

modules/misc/news.nix

@@ -478,6 +478,60 @@ in
           necessary.
         '';
       }
+
+      {
+        time = "2018-01-08T20:39:56+00:00";
+        condition = config.home.sessionVariableSetter != null;
+        message =
+          let
+            opts = {
+              bash = ''
+                Instead the 'programs.bash' module will, when enabled,
+                automatically set session variables. You can safely
+                remove the 'home.sessionVariableSetter' option from your
+                configuration.
+              '';
+
+              zsh = ''
+                Instead the 'programs.zsh' module will, when enabled,
+                automatically set session variables. You can safely
+                remove the 'home.sessionVariableSetter' option from your
+                configuration.
+              '';
+
+              pam = ''
+                Unfortunately setting general session variables using
+                PAM will not be directly supported after this date. The
+                primary reason for this change is its limited support
+                for variable expansion.
+
+                To continue setting session variables from the Home
+                Manager configuration you must either use the
+                'programs.bash' or 'programs.zsh' modules or manually
+                source the session variable file
+
+                    $HOME/.nix-profile/etc/profile.d/hm-session-vars.sh
+
+                within your shell configuration, see the README file for
+                more information. This file requires a Bourne-like shell
+                such as Bash or Z shell but hopefully other shells
+                will be supported in the future.
+
+                If you specifically need to set a session variable using
+                PAM then the new option 'pam.sessionVariables' can be
+                used. It works much the same as 'home.sessionVariables'
+                but its attribute values must be valid within the PAM
+                environment file.
+              '';
+            };
+          in
+            ''
+              The 'home.sessionVariableSetter' option is now deprecated
+              and will be removed on February 8, 2018.
+
+              ${opts.${config.home.sessionVariableSetter}}
+            '';
+      }
     ];
   };
 }

modules/misc/pam.nix

@@ -6,17 +6,35 @@ let
 
   homeCfg = config.home;
 
+  vars =
+    optionalAttrs (homeCfg.sessionVariableSetter == "pam") homeCfg.sessionVariables
+    // config.pam.sessionVariables;
+
 in
 
 {
   meta.maintainers = [ maintainers.rycee ];
 
-  options = {};
+  options = {
+    pam.sessionVariables = mkOption {
+      default = {};
+      type = types.attrs;
+      example = { EDITOR = "vim"; };
+      description = ''
+        Environment variables that will be set for the PAM session.
+        The variable values must be as described in
+        <citerefentry>
+          <refentrytitle>pam_env.conf</refentrytitle>
+          <manvolnum>5</manvolnum>
+        </citerefentry>.
+      '';
+    };
+  };
 
-  config = mkIf (homeCfg.sessionVariableSetter == "pam") {
+  config = mkIf (vars != {}) {
     home.file.".pam_environment".text =
       concatStringsSep "\n" (
-        mapAttrsToList (n: v: "${n} OVERRIDE=${v}") homeCfg.sessionVariables
+        mapAttrsToList (n: v: "${n} OVERRIDE=${toString v}") vars
       ) + "\n";
   };
 }

modules/programs/bash.nix

@@ -131,31 +131,26 @@ in
         map (v: "shopt -s ${v}") cfg.shellOptions
       );
 
-      export = n: v: "export ${n}=\"${toString v}\"";
+      sessionVarsStr = config.lib.shell.exportAll cfg.sessionVariables;
-      setIfNonEmpty = n: v: optionalString (v != "") "${n}=${toString v}";
 
-      histControlStr = concatStringsSep ":" cfg.historyControl;
+      historyControlStr =
-      histIgnoreStr = concatStringsSep ":" cfg.historyIgnore;
+        concatStringsSep "\n" (mapAttrsToList (n: v: "${n}=${v}") (
-
+          {
-      # If Bash is the session variable setter then this is the
+            HISTSIZE = toString cfg.historySize;
-      # attribute set of global session variables, otherwise it is an
+            HISTFILESIZE = toString cfg.historyFileSize;
-      # empty set.
+          }
-      globalEnvVars =
+          // optionalAttrs (cfg.historyControl != []) {
-        optionalAttrs
+            HISTCONTROL = concatStringsSep ":" cfg.historyControl;
-          (config.home.sessionVariableSetter == "bash")
+          }
-          config.home.sessionVariables;
+          // optionalAttrs (cfg.historyIgnore != []) {
-
+            HISTIGNORE = concatStringsSep ":" cfg.historyIgnore;
-      envVarsStr = concatStringsSep "\n" (
+          }
-        mapAttrsToList export (cfg.sessionVariables // globalEnvVars)
+        ));
-      );
     in mkIf cfg.enable {
       programs.bash.bashrcExtra = ''
         # Commands that should be applied only for interactive shells.
         if [[ -n $PS1 ]]; then
-          HISTSIZE=${toString cfg.historySize}
+          ${historyControlStr}
-          HISTFILESIZE=${toString cfg.historyFileSize}
-          ${setIfNonEmpty "HISTCONTROL" histControlStr}
-          ${setIfNonEmpty "HISTIGNORE" histIgnoreStr}
 
           ${shoptsStr}
 
@@ -181,7 +176,11 @@ in
       home.file.".profile".text = ''
         # -*- mode: sh -*-
 
-        ${envVarsStr}
+        ${optionalString (config.home.sessionVariableSetter != "pam") ''
+          . "$HOME/.nix-profile/etc/profile.d/hm-session-vars.sh"
+        ''}
+
+        ${sessionVarsStr}
 
         ${cfg.profileExtra}
       '';

modules/programs/zsh.nix

@@ -11,17 +11,7 @@ let
   pluginsDir = if cfg.dotDir != null then
     relToDotDir "plugins" else ".zsh/plugins";
 
-  export = n: v: "export ${n}=\"${toString v}\"";
+  envVarsStr = config.lib.shell.exportAll cfg.sessionVariables;
-
-  toEnvVarsStr = vars: concatStringsSep "\n" (
-    mapAttrsToList export vars
-  );
-
-  envVars = cfg.sessionVariables // (
-    if config.home.sessionVariableSetter == "zsh" then config.home.sessionVariables else {}
-  );
-
-  envVarsStr = toEnvVarsStr envVars;
 
   aliasesStr = concatStringsSep "\n" (
     mapAttrsToList (k: v: "alias ${k}='${v}'") cfg.shellAliases
@@ -255,6 +245,9 @@ in
 
       home.file."${relToDotDir ".zshenv"}".text = ''
         typeset -U fpath
+        ${optionalString (config.home.sessionVariableSetter != "pam") ''
+          . "$HOME/.nix-profile/etc/profile.d/hm-session-vars.sh"
+        ''}
         ${envVarsStr}
       '';
 

modules/xsession.nix

@@ -82,6 +82,9 @@ in
     };
 
     home.file.".xprofile".text = ''
+        ${optionalString (config.home.sessionVariableSetter != "pam")
+          ''. "$HOME/.nix-profile/etc/profile.d/hm-session-vars.sh"''}
+
         if [[ -e "$HOME/.profile" ]]; then
           . "$HOME/.profile"
         fi