rails: New script `railsdo' and rename home symlink to the app

* New script `railsdo' to help run commands as a rails user

  * The symlink in the home directory is now always called `app'.  It
    was previously named after the application itself.

modules/services/web/rails/default.nix

@@ -13,6 +13,7 @@ let
   options    = import ./options.nix { inherit config lib pkgs; };
   appSystemd = import ./systemd.nix { inherit config pkgs lib; };
   funcs      = import ./functions.nix { inherit config; };
+  scripts    = import ./scripts.nix { inherit lib pkgs; };
 
   ##############################################################################
   # Collect all apps into a single set using the given function:
@@ -111,5 +112,10 @@ in
       enable = true;
       config = concatMapStringsSep "\n" appLogRotation (attrValues cfg.apps);
     };
+
+    # Additional packages to install in the environment:
+    environment.systemPackages = [
+      scripts.system
+    ];
   };
 }

modules/services/web/rails/railsdo.sh

@@ -0,0 +1,37 @@
+#!/bin/sh
+
+################################################################################
+set -e
+set -u
+
+################################################################################
+usage() {
+  cat <<EOF
+Usage: $(basename "$0") name command [option...]
+
+Run a command while logged in as the Rails user NAME.
+
+Example:
+
+  railsdo myapp rake routes
+
+EOF
+}
+
+################################################################################
+if [ $# -lt 2 ] || [ "${1:-}" = "-h" ] || [ "${1:-}" = "--help" ]; then
+  usage
+  exit 1
+fi
+
+################################################################################
+name=$1; shift
+
+################################################################################
+if ! id -u "rails-$name" > /dev/null 2>&1; then
+  >&2 echo "ERROR: $name doesn't appear to be a valid rails application"
+  exit 1
+fi
+
+################################################################################
+sudo --user="rails-$name" --login sh -c "cd app && $*"

modules/services/web/rails/scripts.nix

@@ -1,7 +1,8 @@
 { lib, pkgs, ...}:
 
-pkgs.stdenvNoCC.mkDerivation {
-  name = "rails-scripts";
+{
+  user = pkgs.stdenvNoCC.mkDerivation {
+    name = "rails-user-scripts";
     phases = [ "installPhase" "fixupPhase" ];
 
     installPhase = ''
@@ -16,4 +17,23 @@ pkgs.stdenvNoCC.mkDerivation {
       maintainers = with maintainers; [ pjones ];
       platforms = platforms.all;
     };
+  };
+
+  system = pkgs.stdenvNoCC.mkDerivation {
+    name = "rails-system-scripts";
+    phases = [ "installPhase" "fixupPhase" ];
+
+    installPhase = ''
+      mkdir -p $out/bin
+      substituteAll ${./railsdo.sh} $out/bin/railsdo
+      find $out/bin -type f -exec chmod 555 '{}' ';'
+    '';
+
+    meta = with lib; {
+      description = "Scripts for working with Ruby on Rails applications.";
+      homepage = https://git.devalot.com/pjones/phoebe/;
+      maintainers = with maintainers; [ pjones ];
+      platforms = platforms.all;
+    };
+  };
 }

modules/services/web/rails/systemd.nix

@@ -61,7 +61,7 @@ let
 
         # Additional set up for the home directory:
         mkdir -p ${app.home}/home
-        ln -nfs ${app.package}/share/${app.name} ${app.home}/home/${app.name}
+        ln -nfs ${app.package}/share/${app.name} ${app.home}/home/app
         ln -nfs ${plib.attrsToShellExports "rails-${app.name}-env" (funcs.appEnv app)} ${app.home}/home/.env
         cp ${./profile.sh} ${app.home}/home/.profile
         chmod 0700 ${app.home}/home/.profile
@@ -79,7 +79,7 @@ let
       '' + optionalString (service.isMain && app.database.migrate) ''
         # Migrate the database:
         ${pkgs.sudo}/bin/sudo --user=rails-${app.name} --login \
-          ${scripts}/bin/db-migrate.sh \
+          ${scripts.user}/bin/db-migrate.sh \
             -r ${app.package}/share/${app.name} \
             -s ${app.home}/state
       '';