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searxng/searx/engines/elasticsearch.py

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+# SPDX-License-Identifier: AGPL-3.0-or-later
+""".. sidebar:: info
+
+   - :origin:`elasticsearch.py <searx/engines/elasticsearch.py>`
+   - `Elasticsearch <https://www.elastic.co/elasticsearch/>`_
+   - `Elasticsearch Guide
+     <https://www.elastic.co/guide/en/elasticsearch/reference/current/index.html>`_
+   - `Install Elasticsearch
+     <https://www.elastic.co/guide/en/elasticsearch/reference/current/install-elasticsearch.html>`_
+
+Elasticsearch_ supports numerous ways to query the data it is storing.  At the
+moment the engine supports the most popular search methods (``query_type``):
+
+- ``match``,
+- ``simple_query_string``,
+- ``term`` and
+- ``terms``.
+
+If none of the methods fit your use case, you can select ``custom`` query type
+and provide the JSON payload to submit to Elasticsearch in
+``custom_query_json``.
+
+Example
+=======
+
+The following is an example configuration for an Elasticsearch_ instance with
+authentication configured to read from ``my-index`` index.
+
+.. code:: yaml
+
+  - name: elasticsearch
+    shortcut: es
+    engine: elasticsearch
+    base_url: http://localhost:9200
+    username: elastic
+    password: changeme
+    index: my-index
+    query_type: match
+    # custom_query_json: '{ ... }'
+    enable_http: true
+
+"""
+
+from json import loads, dumps
+from searx.exceptions import SearxEngineAPIException
+
+
+base_url = 'http://localhost:9200'
+username = ''
+password = ''
+index = ''
+search_url = base_url + '/' + index + '/_search'
+query_type = 'match'
+custom_query_json = {}
+show_metadata = False
+categories = ['general']
+
+
+def init(engine_settings):
+    if 'query_type' in engine_settings and engine_settings['query_type'] not in _available_query_types:
+        raise ValueError('unsupported query type', engine_settings['query_type'])
+
+    if index == '':
+        raise ValueError('index cannot be empty')
+
+
+def request(query, params):
+    if query_type not in _available_query_types:
+        return params
+
+    if username and password:
+        params['auth'] = (username, password)
+
+    params['url'] = search_url
+    params['method'] = 'GET'
+    params['data'] = dumps(_available_query_types[query_type](query))
+    params['headers']['Content-Type'] = 'application/json'
+
+    return params
+
+
+def _match_query(query):
+    """
+    The standard for full text queries.
+    searx format: "key:value" e.g. city:berlin
+    REF: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-match-query.html
+    """
+
+    try:
+        key, value = query.split(':')
+    except Exception as e:
+        raise ValueError('query format must be "key:value"') from e
+
+    return {"query": {"match": {key: {'query': value}}}}
+
+
+def _simple_query_string_query(query):
+    """
+    Accepts query strings, but it is less strict than query_string
+    The field used can be specified in index.query.default_field in Elasticsearch.
+    REF: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-simple-query-string-query.html
+    """
+
+    return {'query': {'simple_query_string': {'query': query}}}
+
+
+def _term_query(query):
+    """
+    Accepts one term and the name of the field.
+    searx format: "key:value" e.g. city:berlin
+    REF: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-term-query.html
+    """
+
+    try:
+        key, value = query.split(':')
+    except Exception as e:
+        raise ValueError('query format must be key:value') from e
+
+    return {'query': {'term': {key: value}}}
+
+
+def _terms_query(query):
+    """
+    Accepts multiple terms and the name of the field.
+    searx format: "key:value1,value2" e.g. city:berlin,paris
+    REF: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-terms-query.html
+    """
+
+    try:
+        key, values = query.split(':')
+    except Exception as e:
+        raise ValueError('query format must be key:value1,value2') from e
+
+    return {'query': {'terms': {key: values.split(',')}}}
+
+
+def _custom_query(query):
+    key, value = query.split(':')
+    custom_query = custom_query_json
+    for query_key, query_value in custom_query.items():
+        if query_key == '{{KEY}}':
+            custom_query[key] = custom_query.pop(query_key)
+        if query_value == '{{VALUE}}':
+            custom_query[query_key] = value
+    return custom_query
+
+
+def response(resp):
+    results = []
+
+    resp_json = loads(resp.text)
+    if 'error' in resp_json:
+        raise SearxEngineAPIException(resp_json['error'])
+
+    for result in resp_json['hits']['hits']:
+        r = {key: str(value) if not key.startswith('_') else value for key, value in result['_source'].items()}
+        r['template'] = 'key-value.html'
+
+        if show_metadata:
+            r['metadata'] = {'index': result['_index'], 'id': result['_id'], 'score': result['_score']}
+
+        results.append(r)
+
+    return results
+
+
+_available_query_types = {
+    # Full text queries
+    # https://www.elastic.co/guide/en/elasticsearch/reference/current/full-text-queries.html
+    'match': _match_query,
+    'simple_query_string': _simple_query_string_query,
+    # Term-level queries
+    # https://www.elastic.co/guide/en/elasticsearch/reference/current/term-level-queries.html
+    'term': _term_query,
+    'terms': _terms_query,
+    # Query JSON defined by the instance administrator.
+    'custom': _custom_query,
+}