django-elasticsearch-dsl 6.4.0

Wrapper around elasticsearch-dsl-py for django models

This is a package that allows indexing of django models in elasticsearch. It is built as a thin wrapper around elasticsearch-dsl-py so you can use all the features developed by the elasticsearch-dsl-py team.

Features

• Based on elasticsearch-dsl-py so you can make queries with the Search class.

• Django signal receivers on save and delete for keeping Elasticsearch in sync.

• Management commands for creating, deleting, rebuilding and populating indices.

• Elasticsearch auto mapping from django models fields.

• Complex field type support (ObjectField, NestedField).

• Requirements

  • Django >= 1.10

  • Python 2.7, 3.5, 3.6, 3.7

  • Elasticsearch >= 6.0 < 7.0

Quickstart

Install Django Elasticsearch DSL:

pip install django-elasticsearch-dsl

Then add django_elasticsearch_dsl to the INSTALLED_APPS

You must define ELASTICSEARCH_DSL in your django settings.

For example:

ELASTICSEARCH_DSL={
    'default': {
        'hosts': 'localhost:9200'
    },
}

ELASTICSEARCH_DSL is then passed to elasticsearch-dsl-py.connections.configure (see here).

Then for a model:

# models.py

class Car(models.Model):
    name = models.CharField()
    color = models.CharField()
    description = models.TextField()
    type = models.IntegerField(choices=[
        (1, "Sedan"),
        (2, "Truck"),
        (4, "SUV"),
    ])

To make this model work with Elasticsearch, create a subclass of django_elasticsearch_dsl.Document, create a class Index inside the Document class to define your Elasticsearch indices, names, settings etc and at last register the class using registry.register_document decorator.

# documents.py

from django_elasticsearch_dsl import Document
from django_elasticsearch_dsl.registries import registry
from .models import Car


@registry.register_document
class CarDocument(Document):
    class Index:
        # Name of the Elasticsearch index
        name = 'cars'
        # See Elasticsearch Indices API reference for available settings
        settings = {'number_of_shards': 1,
                    'number_of_replicas': 0}

    class Django:
        model = Car # The model associated with this Document

        # The fields of the model you want to be indexed in Elasticsearch
        fields = [
            'name',
            'color',
            'description',
            'type',
        ]

        # Ignore auto updating of Elasticsearch when a model is saved
        # or deleted:
        # ignore_signals = True
        # Don't perform an index refresh after every update (overrides global setting):
        # auto_refresh = False
        # Paginate the django queryset used to populate the index with the specified size
        # (by default there is no pagination)
        # queryset_pagination = 5000

To create and populate the Elasticsearch index and mapping use the search_index command:

$ ./manage.py search_index --rebuild

Now, when you do something like:

car = Car(
    name="Car one",
    color="red",
    type=1,
    description="A beautiful car"
)
car.save()

The object will be saved in Elasticsearch too (using a signal handler). To get an elasticsearch-dsl-py Search instance, use:

s = CarDocument.search().filter("term", color="red")

# or

s = CarDocument.search().query("match", description="beautiful")

for hit in s:
    print(
        "Car name : {}, description {}".format(hit.name, hit.description)
    )

The previous example returns a result specific to elasticsearch_dsl, but it is also possible to convert the elastisearch result into a real django queryset, just be aware that this costs a sql request to retrieve the model instances with the ids returned by the elastisearch query.

s = CarDocument.search().filter("term", color="blue")[:30]
qs = s.to_queryset()
# qs is just a django queryset and it is called with order_by to keep
# the same order as the elasticsearch result.
for car in qs:
    print(car.name)

Fields

Once again the django_elasticsearch_dsl.fields are subclasses of elasticsearch-dsl-py fields. They just add support for retrieving data from django models.

Using Different Attributes for Model Fields

Let’s say you don’t want to store the type of the car as an integer, but as the corresponding string instead. You need some way to convert the type field on the model to a string, so we’ll just add a method for it:

# models.py

class Car(models.Model):
    # ... #
    def type_to_string(self):
        """Convert the type field to its string representation
        (the boneheaded way).
        """
        if self.type == 1:
            return "Sedan"
        elif self.type == 2:
            return "Truck"
        else:
            return "SUV"

Now we need to tell our Document subclass to use that method instead of just accessing the type field on the model directly. Change the CarDocument to look like this:

# documents.py

from django_elasticsearch_dsl import Document, fields

# ... #

@registry.register_document
class CarDocument(Document):
    # add a string field to the Elasticsearch mapping called type, the
    # value of which is derived from the model's type_to_string attribute
    type = fields.TextField(attr="type_to_string")

    class Django:
        model = Car
        # we removed the type field from here
        fields = [
            'name',
            'color',
            'description',
        ]

After a change like this we need to rebuild the index with:

$ ./manage.py search_index --rebuild

Using prepare_field

Sometimes, you need to do some extra prepping before a field should be saved to Elasticsearch. You can add a prepare_foo(self, instance) method to a Document (where foo is the name of the field), and that will be called when the field needs to be saved.

# documents.py

# ... #

class CarDocument(Document):
    # ... #

    foo = TextField()

    def prepare_foo(self, instance):
        return " ".join(instance.foos)

Handle relationship with NestedField/ObjectField

For example for a model with ForeignKey relationships.

# models.py

class Car(models.Model):
    name = models.CharField()
    color = models.CharField()
    manufacturer = models.ForeignKey('Manufacturer')

class Manufacturer(models.Model):
    name = models.CharField()
    country_code = models.CharField(max_length=2)
    created = models.DateField()

class Ad(models.Model):
    title = models.CharField()
    description = models.TextField()
    created = models.DateField(auto_now_add=True)
    modified = models.DateField(auto_now=True)
    url = models.URLField()
    car = models.ForeignKey('Car', related_name='ads')

You can use an ObjectField or a NestedField.

# documents.py

from django_elasticsearch_dsl import Document, fields
from .models import Car, Manufacturer, Ad

@registry.register_document
class CarDocument(Document):
    manufacturer = fields.ObjectField(properties={
        'name': fields.TextField(),
        'country_code': fields.TextField(),
    })
    ads = fields.NestedField(properties={
        'description': fields.TextField(analyzer=html_strip),
        'title': fields.TextField(),
        'pk': fields.IntegerField(),
    })

    class Index:
        name = 'cars'

    class Django:
        model = Car
        fields = [
            'name',
            'color',
        ]
        related_models = [Manufacturer, Ad]  # Optional: to ensure the Car will be re-saved when Manufacturer or Ad is updated

    def get_queryset(self):
        """Not mandatory but to improve performance we can select related in one sql request"""
        return super(CarDocument, self).get_queryset().select_related(
            'manufacturer'
        )

    def get_instances_from_related(self, related_instance):
        """If related_models is set, define how to retrieve the Car instance(s) from the related model.
        The related_models option should be used with caution because it can lead in the index
        to the updating of a lot of items.
        """
        if isinstance(related_instance, Manufacturer):
            return related_instance.car_set.all()
        elif isinstance(related_instance, Ad):
            return related_instance.car

Field Classes

Most Elasticsearch field types are supported. The attr argument is a dotted “attribute path” which will be looked up on the model using Django template semantics (dict lookup, attribute lookup, list index lookup). By default the attr argument is set to the field name.

For the rest, the field properties are the same as elasticsearch-dsl fields.

So for example you can use a custom analyzer:

# documents.py

# ... #

html_strip = analyzer(
    'html_strip',
    tokenizer="standard",
    filter=["standard", "lowercase", "stop", "snowball"],
    char_filter=["html_strip"]
)

@registry.register_document
class CarDocument(Document):
    description = fields.TextField(
        analyzer=html_strip,
        fields={'raw': fields.KeywordField()}
    )

    class Django:
        model = Car
        fields = [
            'name',
            'color',
        ]

Available Fields

• Simple Fields

  • BooleanField(attr=None, **elasticsearch_properties)

  • ByteField(attr=None, **elasticsearch_properties)

  • CompletionField(attr=None, **elasticsearch_properties)

  • DateField(attr=None, **elasticsearch_properties)

  • DoubleField(attr=None, **elasticsearch_properties)

  • FileField(attr=None, **elasticsearch_properties)

  • FloatField(attr=None, **elasticsearch_properties)

  • IntegerField(attr=None, **elasticsearch_properties)

  • IpField(attr=None, **elasticsearch_properties)

  • GeoPointField(attr=None, **elasticsearch_properties)

  • GeoShapField(attr=None, **elasticsearch_properties)

  • ShortField(attr=None, **elasticsearch_properties)

  • StringField(attr=None, **elasticsearch_properties)

• Complex Fields

  • ObjectField(properties, attr=None, **elasticsearch_properties)

  • NestedField(properties, attr=None, **elasticsearch_properties)

• Elasticsearch >=5 Fields

  • TextField(attr=None, **elasticsearch_properties)

  • KeywordField(attr=None, **elasticsearch_properties)

properties is a dict where the key is a field name, and the value is a field instance.

Index

In typical scenario using class Index on a Document class is sufficient to perform any action. In a few cases though it can be useful to manipulate an Index object directly. To define an Elasticsearch index you must instantiate a elasticsearch_dsl.Index class and set the name and settings of the index. After you instantiate your class, you need to associate it with the Document you want to put in this Elasticsearch index and also add the registry.register_document decorator.

# documents.py
from elasticsearch_dsl import Index
from django_elasticsearch_dsl import Document
from .models import Car, Manufacturer

# The name of your index
car = Index('cars')
# See Elasticsearch Indices API reference for available settings
car.settings(
    number_of_shards=1,
    number_of_replicas=0
)

@registry.register_document
@car.document
class CarDocument(Document):
    class Django:
        model = Car
        fields = [
            'name',
            'color',
        ]

@registry.register_document
class ManufacturerDocument(Document):
    class Index:
        name = 'manufacture'
        settings = {'number_of_shards': 1,
                    'number_of_replicas': 0}

    class Django:
        model = Car
        fields = [
            'name',
            'country_code',
        ]

When you execute the command:

$ ./manage.py search_index --rebuild

This will create two index named cars and manufacture in Elasticsearch with appropriate mapping.

Management Commands

Delete all indices in Elasticsearch or only the indices associate with a model (–models):

$ search_index --delete [-f] [--models [app[.model] app[.model] ...]]

Create the indices and their mapping in Elasticsearch:

$ search_index --create [--models [app[.model] app[.model] ...]]

Populate the Elasticsearch mappings with the django models data (index need to be existing):

$ search_index --populate [--models [app[.model] app[.model] ...]]

Recreate and repopulate the indices:

$ search_index --rebuild [-f] [--models [app[.model] app[.model] ...]]

Settings

ELASTICSEARCH_DSL_AUTOSYNC

Default: True

Set to False to globally disable auto-syncing.

ELASTICSEARCH_DSL_INDEX_SETTINGS

Default: {}

Additional options passed to the elasticsearch-dsl Index settings (like number_of_replicas or number_of_shards).

ELASTICSEARCH_DSL_AUTO_REFRESH

Default: True

Set to False not force an [index refresh](https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-refresh.html) with every save.

ELASTICSEARCH_DSL_SIGNAL_PROCESSOR

This (optional) setting controls what SignalProcessor class is used to handle Django’s signals and keep the search index up-to-date.

An example:

ELASTICSEARCH_DSL_SIGNAL_PROCESSOR = 'django_elasticsearch_dsl.signals.RealTimeSignalProcessor'

Defaults to django_elasticsearch_dsl.signals.RealTimeSignalProcessor.

You could, for instance, make a CelerySignalProcessor which would add update jobs to the queue to for delayed processing.

Testing

You can run the tests by creating a Python virtual environment, installing the requirements from requirements_test.txt (pip install -r requirements_test):

$ python runtests.py

Or:

$ make test

$ make test-all # for tox testing

For integration testing with a running Elasticsearch server:

$ python runtests.py --elasticsearch [localhost:9200]

TODO

• Add support for –using (use another Elasticsearch cluster) in management commands.

• Add management commands for mapping level operations (like update_mapping….).

• Dedicated documentation.

• Generate ObjectField/NestField properties from a Document class.

• More examples.

• Better ESTestCase and documentation for testing

History

0.5.1 (2018-11-07)

• Limit elastsearch-dsl to supported versions

0.5.0 (2018-04-22)

• Add Support for Elasticsearch 6 thanks to HansAdema

Breaking Change:

Django string fields now point to ES text field by default. Nothing should change for ES 2.X but if you are using ES 5.X, you may need to rebuild and/or update some of your documents.

0.4.5 (2018-04-22)

• Fix prepare with related models when deleted (See PR #99)

• Fix unwanted calls to get_instances_from_related

• Fix for empty ArrayField (CBinyenya)

• Fix nested OneToOneField when related object doesn’t exist (CBinyenya)

• Update elasticsearch-dsl minimal version

0.4.4 (2017-12-13)

• Fix to_queryset with es 5.0/5.1

0.4.3 (2017-12-12)

• Fix syncing of related objects when deleted

• Add django 2.0 support

0.4.2 (2017-11-27)

• Convert lazy string to string before serialization

• Readme update (arielpontes)

0.4.1 (2017-10-17)

• Update example app with get_instances_from_related

• Typo/grammar fixes

0.4.0 (2017-10-07)

• Add a method on the Search class to return a django queryset from an es result

• Add a queryset_pagination option to DocType.Meta for allow the pagination of big django querysets during the index populating

• Remove the call to iterator method for the django queryset

• Fix DocType inheritance. The DocType is store in the registry as a class and not anymore as an instance

0.3.0 (2017-10-01)

• Add support for resynching ES documents if related models are updated (HansAdema)

• Better management for django FileField and ImageField

• Fix some errors in the doc (barseghyanartur, diwu1989)

0.2.0 (2017-07-02)

• Replace simple model signals with easier to customise signal processors (barseghyanartur)

• Add options to disable automatic index refreshes (HansAdema)

• Support defining DocType indexes through Meta class (HansAdema)

• Add option to set default Index settings through Django config (HansAdema)

0.1.0 (2017-05-26)

• First release on PyPI.