Use Site Alias Manager in ssh command.

src/Commands/core/SshCommands.php

@@ -3,9 +3,13 @@
 
 use Drush\Commands\DrushCommands;
 use Drush\Log\LogLevel;
+use Drush\SiteAlias\SiteAliasManagerAwareInterface;
+use Drush\SiteAlias\SiteAliasManagerAwareTrait;
+use Drush\SiteAlias\SiteAliasName;
 
-class SshCommands extends DrushCommands
+class SshCommands extends DrushCommands implements SiteAliasManagerAwareInterface
 {
+    use SiteAliasManagerAwareTrait;
 
     /**
      * Connect to a Drupal site's server via SSH.
@@ -35,6 +39,41 @@ public function ssh(array $args, $options = ['cd' => true])
         }
         $command = implode(' ', $args);
 
+        // TODO: Remove when no longer needed.
+        if (!$this->hasSiteAliasManager()) {
+            return $this->legacySsh($command, $options);
+        }
+
+        $alias = $this->siteAliasManager()->getSelf();
+        if ($alias->isNone()) {
+            throw new \Exception('A site alias is required. The way you call ssh command has changed to `drush @alias ssh`.');
+        }
+
+        // Local sites run their bash without SSH.
+        if (!$alias->isRemote()) {
+            $return = drush_invoke_process('@self', 'core-execute', array($command), array('escape' => false));
+            return $return['object'];
+        }
+
+        // We have a remote site - build ssh command and run.
+        $interactive = false;
+        $cd = $options['cd'];
+        if (empty($command)) {
+            $command = 'bash -l';
+            $interactive = true;
+        }
+        $config = $alias->exportConfig();
+        $site = $config->get('options', []);
+
+        $cmd = drush_shell_proc_build($site, $command, $cd, $interactive);
+        $status = drush_shell_proc_open($cmd);
+        if ($status != 0) {
+            throw new \Exception(dt('An error @code occurred while running the command `@command`', array('@command' => $cmd, '@code' => $status)));
+        }
+    }
+
+    protected function legacySsh($command, $options = ['cd' => true])
+    {
         if (!$alias = drush_get_context('DRUSH_TARGET_SITE_ALIAS')) {
             throw new \Exception('A site alias is required. The way you call ssh command has changed to `drush @alias ssh`.');
         }

src/SiteAlias/AliasRecord.php

@@ -101,6 +101,11 @@ public function isRemote()
         return $this->has('host');
     }
 
+    public function isNone()
+    {
+        return empty($this->root());
+    }
+
     /**
      * Return the 'root' element of this alias if this alias record
      * is local.