Integrate Elasticsearch with WordPress.

• Latest Stable: v1.0
• Contributors: @aaronholbrook, @tlovett1, @mattonomics, @ivanlopez, @colegeissinger, @cmmarslender, @ghosttoast

Let's face it, WordPress search is rudimentary at best. Poor performance, inflexible and rigid matching algorithms (which means no comprehension of 'close' queries), the inability to search metadata and taxonomy information, no way to determine categories of your results and most importantly the overall relevancy of results is poor.

Elasticsearch is a search server based on Lucene. It provides a distributed, multitenant-capable full-text search engine with a RESTful web interface and schema-free JSON documents.

Coupling WordPress with Elasticsearch allows us to do amazing things with search including:

• Relevant results
• Autosuggest
• Fuzzy matching (catch misspellings as well as 'close' queries)
• Proximity and geographic queries
• Search metadata
• Search taxonomies
• Facets
• Search all sites on a multisite install
• The list goes on...

The goal of ElasticPress is to integrate WordPress with Elasticsearch. This plugin integrates with the WP_Query object returning results from Elasticsearch instead of MySQL.

There are other Elasticsearch integration plugins available for WordPress. ElasticPress, unlike others, offers multi-site search. Elasticsearch is a complex topic and integration results in complex problems. Rather than providing a limited, clunky UI, we elected to instead provide full control via WP-CLI.

1. First, you will need to properly install and configure Elasticsearch.
2. ElasticPress requires WP-CLI. Install it by following these instructions.
3. Install the plugin in WordPress. You can download a zip via Github and upload it using the WP plugin uploader.

First, make sure you have Elasticsearch and WP-CLI configured properly.

1. Define the constant EP_HOST in your wp-config.php file with the connection (and port) of your Elasticsearch application. For example:

define( 'EP_HOST', 'http://192.168.50.4:9200' );

The proceeding sets depend on whether you are configuring for single site or multi-site with cross-site search capabilities.

2. Activate the plugin.
3. Using wp-cli, do an initial sync (with mapping) with your ES server by running the following commands:

wp elasticpress index --setup

2. Network activate the plugin
3. Using wp-cli, do an initial sync (with mapping) with your ES server by running the following commands:

wp elasticpress index --setup --network-wide

After your index finishes, WP_Query will be integrated with Elasticsearch and support a few special parameters.

Creating indices is handled automatically by ElasticPress. Index names are automatically generated based on site URL.

After running an index, ElasticPress integrates with WP_Query. The end goal is to support all the parameters available to WP_Query so the transition is completely transparent. Right now, our WP_Query integration supports many of the relevant WP_Query parameters and adds a couple special ones.

• s (string)

  Search keyword. By default used to search against post_title, post_content, and post_excerpt.

• posts_per_page (int)

  Number of posts to show per page. Use -1 to show all posts (the offset parameter is ignored with a -1 value). Set the paged parameter to paginate based on posts_per_page.

• tax_query (array)

  Filter posts by terms in taxonomies. Takes an array of form:

  new WP_Query( array(
      's' => 'search phrase',
      'tax_query' => array(
          array(
              'taxonomy' => 'taxonomy-name',
              'terms' => array( ... ),
          )
      ),
  ));

  tax_query accepts an array of arrays where each inner array only supports taxonomy (string) and terms (string|array) parameters. terms is a slug, either in string or array form.

• post_type (string/array)

  Filter posts by post type. any wil search all public post types.

• offset (int)

  Number of posts to skip in ascending order.

• paged (int)

  Page number of posts to be used with posts_per_page.

• author (int)

  Show posts associated with certain author ID.

• author_name (string)

  Show posts associated with certain author. Use user_nicename (NOT name).

• orderby (string)

  Order results by field name instead of relevance. Currently only supports: title, name, and relevance (default).

• order (string)

  Which direction to order results in. Accepts ASC and DESC. Default is DESC.

The following are special parameters that are only supported by ElasticPress.

• search_fields (array)

  If not specified, defaults to array( 'post_title', 'post_excerpt', 'post_content' ).

  • post_title (string)

    Applies current search to post titles.

  • post_content (string)

    Applies current search to post content.

  • post_excerpt (string)

    Applies current search to post excerpts.

  • taxonomies (string => array/string)

    Applies the current search to terms within a taxonomy or taxonomies. The following will fuzzy search across post_title, post_excerpt, post_content, and terms within taxonomies category and post_tag:

    new WP_Query( array(
        's' => 'term search phrase',
        'search_fields' => array(
            'post_title',
            'post_content',
            'post_excerpt',
            'taxonomies' => array( 'category', 'post_tag' ),
        )
    ));

  • meta (string => array/string)

    Applies the current search to post meta. The following will fuzzy search across post_title, post_excerpt, post_content, and post meta keys meta_key_1 and meta_key_2:

    new WP_Query( array(
        's' => 'meta search phrase',
        'search_fields' => array(
            'post_title',
            'post_content',
            'post_excerpt',
            'meta' => array( 'meta_key_1', 'meta_key_2' ),
        )
    ));

  • author_name (string)

    Applies the current search to author login names. The following will fuzzy search across post_title, post_excerpt, post_content and author user_login:

    new WP_Query( array(
        's' => 'username',
        'search_fields' => array(
            'post_title',
            'post_content',
            'post_excerpt',
            'author_name',
        )
    ));

• aggs (array)

  Add aggregation results to your search result. For example:

  new WP_Query( array(
      's' => 'search phrase',
      'aggs' => array(
          'name' => 'name-of-aggregation', // (can be whatever you'd like)
          'use-filter' => true // (*bool*) used if you'd like to apply the other filters (i.e. post type, tax_query, author), to the aggregation
          'aggs' => array(
              'name' => 'name-of-sub-aggregation',
              'terms' => array(
                  'field' => 'terms.name-of-taxonomy.name-of-term',
              ),
          ),
      ),
  ));

• sites (int/string/array)

  This parameter only applies in a multi-site environment. It lets you search for posts on specific sites or across the network.

  By default, sites defaults to current which searches the current site on the network:

  new WP_Query( array(
      's' => 'search phrase',
      'sites' => 'current',
  ));

  You can search on all sites across the network:

  new WP_Query( array(
      's' => 'search phrase',
      'sites' => 'all',
  ));

  You can also specify specific sites by id on the network:

  new WP_Query( array(
      's' => 'search phrase',
      'sites' => 3,
  ));

  You can even specify a group of specific sites on the network:

  new WP_Query( array(
      's' => 'search phrase',
      'sites' => array( 2, 3 ),
  ));

Follow the configuration instructions above to setup the plugin.

Within the terminal change directories to the plugin folder. Initialize your testing environment by running the following command:

For VVV users:

bash bin/install-wp-tests.sh wordpress_test root root localhost latest

For VIP Quickstart users:

bash bin/install-wp-tests.sh wordpress_test root '' localhost latest

where:

• wordpress_test is the name of the test database (all data will be deleted!)
• root is the MySQL user name
• root is the MySQL user password (if you're running VVV). Blank if you're running VIP Quickstart.
• localhost is the MySQL server host
• latest is the WordPress version; could also be 3.7, 3.6.2 etc.

Our test suite depends on a running Elasticsearch server. You can supply a host to PHPUnit as an environmental variable like so:

EP_HOST="http://192.168.50.4:9200" phpunit

If you identify any errors or have an idea for improving the plugin, please open an issue. We're excited to see what the community thinks of this project, and we would love your input!