Add a flag to enable Persona support

It's disabled by default.  To enable, add the following to hydra.conf:

  enable_persona = 1

src/lib/Hydra/Controller/Root.pm

@@ -24,6 +24,7 @@ sub begin :Private {
     $c->stash->{tracker} = $ENV{"HYDRA_TRACKER"};
     $c->stash->{flashMsg} = $c->flash->{flashMsg};
     $c->stash->{successMsg} = $c->flash->{successMsg};
+    $c->stash->{personaEnabled} = $c->config->{enable_persona} // "0" eq "1";
 
     if (scalar(@args) == 0 || $args[0] ne "static") {
         $c->stash->{nrRunningBuilds} = $c->model('DB::Builds')->search({ finished => 0, busy => 1 }, {})->count();

src/lib/Hydra/Controller/User.pm

@@ -48,6 +48,8 @@ sub persona_login :Path('/persona-login') Args(0) {
     my ($self, $c) = @_;
     requirePost($c);
 
+    error($c, "Persona support is not enabled.") unless $c->stash->{personaEnabled};
+
     my $assertion = $c->req->params->{assertion} or die;
 
     my $ua = new LWP::UserAgent;

src/root/layout.tt

@@ -101,11 +101,13 @@
 
     <script>
       function doLogout() {
+        [% IF c.user_exists %]
           $.post("[% c.uri_for('/logout') %]")
             .done(function(data) {
               window.location.reload();
             })
             .fail(function() { bootbox.alert("Server request failed!"); });
+        [% END %]
       }
     </script>
 
@@ -124,7 +126,8 @@
               url: "[% c.uri_for('/persona-login') %]",
               data: "assertion=" + assertion,
               type: 'POST',
-              success: function(data) { window.location.reload(); }
+              success: function(data) { window.location.reload(); },
+              postError: function() { navigator.id.logout(); }
             });
           },
           onlogout: doLogout

src/root/static/js/common.js

@@ -135,6 +135,7 @@ function requestJSON(args) {
             bootbox.alert("Server error: " + escapeHTML(data.responseText));
         else
             bootbox.alert("Unknown server error!");
+        if (args.postError) args.postError(data);
     };
     return $.ajax(args);
 };

src/root/topbar.tt

@@ -123,6 +123,7 @@
       <a href="#" id="persona-signout">Sign out</a>
     </li>
   [% ELSE %]
+    [% IF personaEnabled %]
       [% WRAPPER makeSubMenu title="Sign in" %]
         <li>
           <a href="#" id="persona-signin">
@@ -134,6 +135,11 @@
           <a href="#hydra-signin" data-toggle="modal">Sign in with a Hydra account</a>
         </li>
       [% END %]
+    [% ELSE %]
+      <li>
+        <a href="#hydra-signin" data-toggle="modal">Sign in</a>
+      </li>
+    [% END %]
   [% END %]
 
 </ul>