add drush migrate:import userid option

Switches the user running the migration to the one indicated, necessary for JWT authentication to work for generating derivatives.

Resolves #4

README.md

@@ -19,8 +19,7 @@ Note: using drush with migrate_tools is optional, but the instructions assume it
 0. Copy the data directory to your drupal web root (e.g. in my tests the drupal web root is `/var/www/drupalvm/drupal/web` and the data directory is `/var/www/drupalvm/drupal/web/data`).
 0. Copy the migrate_cdm and unlv_image directories to your modules directory.
 0. Enable the modules. E.g. `drush en -y migrate_tools migrate_apollo`.
-0. Run the migration. E.g. `drush -l http://localhost:8000 mim --all`. *Note: drush must be run by the webserver user because the claw_file migration copies files to the "public://directory". E.g.* `sudo -u www-data drush -l http://localhost:8000 mim --all` *if you are using vagrant.*
-0. Generate service images. *Still addressing issues with service file generation. Until we figure out that problem you will need to do it yourself by going to the content page, selecting all the items you migrated, and then use the "Generate a service file from image preservation master". This will trigger both the service image and, as a chain reaction, the thumbnail generation.*
+0. Run the migration. E.g. `drush -l http://localhost:8000 mim --userid=1 --all`. *Note: drush must be run by the webserver user because the claw_file migration copies files to the "public://directory". E.g.* `sudo -u www-data drush -l http://localhost:8000 mim --userid=1 --all` *if you are using vagrant. Also, the userid flag is specific to the migrate:import command, it provides the necessary user information to the JWT authentication to enable derivatives.*
 0. See a wonderful list of the newly migrated images on your Drupal site's front page!
 
 # Combining People and Subject entities in a single column

migrate_apollo/config/install/migrate_plus.migration.claw_image.yml

@@ -20,6 +20,7 @@ source:
   constants:
     collection_alias: 'apollo'
     image: 'Image'
+    uid: 1 # UID of Admin user, may be changed to uid of someone with permission to create items
   column_names:
     0:
       digital_id: 'Digital ID'
@@ -41,6 +42,7 @@ process:
     default_value: unlv_image
 
   # One-to-One mappings
+  uid: constants/uid
   field_digital_id: digital_id
   title: title
   field_description: description

migrate_apollo/config/install/migrate_plus.migration.claw_media.yml

@@ -16,6 +16,7 @@ source:
     - digital_id
   constants:
     preservation_master: 'Preservation Master'
+    uid: 1 # UID of Admin user, may be changed to uid of someone with permission to create items
   column_names:
     0:
       digital_id: 'Digital ID' # identifier key
@@ -27,6 +28,8 @@ process:
     source: digital_id
     no_stub: true
 
+  uid: constants/uid
+
   # Lookup the Tiff we just migrated
   field_media_file/target_id:
     plugin: migration_lookup

migrate_apollo/drush.services.yml

@@ -0,0 +1,5 @@
+services:
+  migrate_apollo.commands:
+    class: \Drupal\migrate_apollo\Commands\MigrateApolloCommands
+    tags:
+      - { name: drush.command }

migrate_apollo/src/Commands/MigrateApolloCommands.php

@@ -0,0 +1,83 @@
+<?php
+
+namespace Drupal\migrate_apollo\Commands;
+
+use Consolidation\AnnotatedCommand\CommandData;
+use Drupal\Core\Session\UserSession;
+use Drupal\Core\Session\AccountSwitcherInterface;
+use Drupal\migrate_tools\Commands\MigrateToolsCommands;
+use Drupal\user\Entity\User;
+use Drush\Commands\DrushCommands;
+
+/**
+ * Adds a userid option to migrate:import
+ *
+ * ... because the --user option was removed from drush 9.
+ */
+class MigrateApolloCommands extends DrushCommands {
+
+  /**
+  * @hook option migrate:import
+  * @option userid User ID to run the migration.
+  */
+  public function optionsetImportUser($options = ['userid' => self::REQ])
+  {
+  }
+
+  /**
+   * @hook validate migrate:import
+   */
+  public function validateUser(CommandData $commandData)
+  {
+    $userid = $commandData->input()->getOption('userid');
+    if($userid)
+    {
+      $account = \Drupal\user\Entity\User::load($userid);
+      if (!$account) {
+          throw new \Exception("User ID does not match an existing user.");
+      }
+    }
+  }
+
+  /**
+  * @hook pre-command migrate:import
+  */
+  public function preImport(CommandData $commandData)
+  {
+    //
+    $userid = $commandData->input()->getOption('userid');
+    if ($userid)
+    {
+      $account = \Drupal\user\Entity\User::load($userid);
+      $accountSwitcher = \Drupal::service('account_switcher');
+      $userSession = new UserSession([
+                                      'uid' => $account->id(),
+                                      'name'=>$account->getUsername(),
+                                      'roles'=>$account->getRoles()
+                                    ]);
+      $accountSwitcher->switchTo($userSession);
+      $this->logger()->notice(
+          dt(
+              'Now acting as user ID @id',
+              ['@id'=>\Drupal::currentUser()->id()]
+            )
+      );
+    }
+  }
+
+  /**
+   * @hook post-command migrate:import
+   */
+  public function postImport($result, CommandData $commandData)
+  {
+    if ($commandData->input()->getOption('userid'))
+    {
+      $accountSwitcher = \Drupal::service('account_switcher');
+      $this->logger()->notice(dt(
+                                  'Switching back from user @uid.',
+                                  ['@uid'=>\Drupal::currentUser()->id()]
+                                ));
+      $accountSwitcher->switchBack();
+    }
+  }
+}