File migration finds 0 (zero) items

Question

I'm trying to import all files from a D7 database via a custom migration. As thinks weren't working as expected I started off with a copy of the stanard d7_file migration template:

    # Every migration that references a file by Drupal 7 fid should specify this
# migration as an optional dependency.
id: lbdp7_files
label: Files
migration_group: lbdp7
migration_tags:
  - Drupal 7
source:
  plugin: lbdp7_file
  constants:
    # source_base_path must be set by the tool configuring this migration. It
    # represents the fully qualified path relative to which uris in the files
    # table are specified, and must end with a /. See source_full_path
    # configuration in this migration's process pipeline as an example.
    source_base_path: ''
process:
  # If you are using this file to build a custom migration consider removing
  # the fid field to allow incremental migrations.
  fid: fid
  filename: filename
  source_full_path:
    -
      plugin: concat
      delimiter: /
      source:
        - constants/source_base_path
        - filepath
    -
      plugin: urlencode
  uri:
    plugin: file_copy
    source:
      - '@source_full_path'
      - uri
  filemime: filemime
  # filesize is dynamically computed when file entities are saved, so there is
  # no point in migrating it.
  # filesize: filesize
  status: status
  # Drupal 7 didn't keep track of the file's creation or update time -- all it
  # had was the vague "timestamp" column. So we'll use it for both.
  created: timestamp
  changed: timestamp
  uid: uid
destination:
  plugin: entity:file

The source plguin lbdp7_file is also just the standard version:

<?php

namespace Drupal\lb_dp7_migration\Plugin\migrate\source;

use Drupal\Core\Database\Query\Condition;
use Drupal\migrate\Row;
use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;

/**
 * Drupal 7 file source from database.
 *
 * @MigrateSource(
 *   id = "lbdp7_file"
 * )
 */
class File extends DrupalSqlBase {

  /**
   * The public file directory path.
   *
   * @var string
   */
  protected $publicPath;

  /**
   * The private file directory path, if any.
   *
   * @var string
   */
  protected $privatePath;

  /**
   * The temporary file directory path.
   *
   * @var string
   */
  protected $temporaryPath;

  /**
   * {@inheritdoc}
   */
  public function query() {
    $query = $this->select('file_managed', 'f')
      ->fields('f')
      ;

    // Filter by scheme(s), if configured.
    if (isset($this->configuration['scheme'])) {
      $schemes = array();
      // Accept either a single scheme, or a list.
      foreach ((array) $this->configuration['scheme'] as $scheme) {
        $schemes[] = rtrim($scheme) . '://';
      }
      $schemes = array_map([$this->getDatabase(), 'escapeLike'], $schemes);

      // uri LIKE 'public://%' OR uri LIKE 'private://%'
      $conditions = new Condition('OR');
      foreach ($schemes as $scheme) {
        $conditions->condition('uri', $scheme . '%', 'LIKE');
      }
      $query->condition($conditions);
    }
    //echo $query->__toString();
    return $query;
  }

  /**
   * {@inheritdoc}
   */
  protected function initializeIterator() {
    $this->publicPath = $this->variableGet('file_public_path', 'sites/default/files');
    $this->privatePath = $this->variableGet('file_private_path', NULL);
    $this->temporaryPath = $this->variableGet('file_temporary_path', '/tmp');
    return parent::initializeIterator();
  }

  /**
   * {@inheritdoc}
   */
  public function prepareRow(Row $row) {
    // Compute the filepath property, which is a physical representation of
    // the URI relative to the Drupal root.
    $path = str_replace(['public:/', 'private:/', 'temporary:/'], [$this->publicPath, $this->privatePath, $this->temporaryPath], $row->getSourceProperty('uri'));
    // At this point, $path could be an absolute path or a relative path,
    // depending on how the scheme's variable was set. So we need to shear out
    // the source_base_path in order to make them all relative.
    $path = str_replace($this->configuration['constants']['source_base_path'], NULL, $path);
    $row->setSourceProperty('filepath', $path);
    return parent::prepareRow($row);
  }

  /**
   * {@inheritdoc}
   */
  public function fields() {
    return array(
      'fid' => $this->t('File ID'),
      'uid' => $this->t('The {users}.uid who added the file. If set to 0, this file was added by an anonymous user.'),
      'filename' => $this->t('File name'),
      'filepath' => $this->t('File path'),
      'filemime' => $this->t('File MIME Type'),
      'status' => $this->t('The published status of a file.'),
      'timestamp' => $this->t('The time that the file was added.'),
    );
  }

  /**
   * {@inheritdoc}
   */
  public function getIds() {
    $ids['fid']['type'] = 'integer';
    return $ids;
  }

}

If I evaluate the query in the source plugin query() function via echo $query->__toString(); I see that the query is SELECT f.* from file_managed f; just as expected.

The problem is that drush ms says that there are 0 items to import. Can't be a database config problem as I have other migrations which work perfectly using the same db connection from settings.php. The table file_managed is populated with over 7000 items...

Any ideas what the problem could be?

Many thanks in advance!

Answer 1

Have you checked the migrate messages and message map for the migration? I'm guess you might see that all the migrations have failed. Does the D8 site have access to the files? And is source_base_path set (see the comment in the migration template)?

Answer 2

Ok, turns out it was a simple mistake I made. I forgot about setting the right database conenction in the migration.yml. So setting the attributes key and target for the source plugin resolved the issue.