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This is a package that allows indexing of django models in elasticsearch with elasticsearch-dsl-py.

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Django Elasticsearch DSL

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This is a package that allows indexing of django models in elasticsearch. It is built as a tin 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 query with the Search class.
  • Django signal receivers on save and delete for keeping Elasticsearch in sync.
  • Management commands for create, delete, rebuild indices and populate them.
  • Elasticsearch auto mapping from django models fields.
  • Complex field type support (ObjectField, NestedField).
  • Requirements
    • Django >= 1.8
    • Python 2.7, 3.4, 3.5, 3.6
    • Elasticsearch >= 2.0 < 6.0

Quickstart

Install Django Elasticsearch DSL:

pip install django-elasticsearch-dsl

# Elasticsearch 5.x
pip install 'elasticsearch-dsl>=5.0,<6.0'

# Elasticsearch 2.x
pip install 'elasticsearch-dsl>=2.0,<3.0'

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.DocType. And create a django_elasticsearch_dsl.Index to define your Elasticsearch indices names and settings. This classes must be define in a documents.py file.

# documents.py

from django_elasticsearch_dsl import DocType, Index
from .models import Car

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


@car.doc_type
class CarDocument(DocType):
    class Meta:
        model = Car # The model associate with this DocType
        fields = [
            'name',
            'color',
            'description',
            'type',
        ] # the fields of the model you want to be indexed in Elasticsearch

        # ignore_signals = True # To ignore auto updating of Elasticsearch when a model is save or delete

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 a 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))

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 DocType 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 DocType, fields

# ... #

@car.doc_type
class CarDocument(DocType):
    # 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.StringField(attr="type_to_string")

    class Meta:
        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 DocType (where foo is the name of the field), and that will be called when the field needs to be saved.

# documents.py

# ... #

class CarDocument(DocType):
    # ... #

    foo = StringField()

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

Handle relationship with NestedField/ObjecField

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')

    # This function will be called by the ads NestedField from the CarDocument
    def ads(self):
        return self.ad_set.all()

You can use an ObjecField or NestedField.

# documents.py

from django_elasticsearch_dsl import DocType, Index
from .models import Car

car = Index('cars')
car.settings(
    number_of_shards=1,
    number_of_replicas=0
)


@car.doc_type
class CarDocument(DocType):
    manufacturer = fields.ObjectField(properties={
        'name': fields.StringField(),
        'country_code': fields.StringField(),
    })
    ads = fields.NestedField(properties={
        'description': fields.StringField(analyzer=html_strip),
        'title': fields.StringField(),
        'pk': fields.IntegerField(),
    })

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

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

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"]
)

@car.doc_type
class CarDocument(DocType):
    description = fields.StringField(
        analyzer=html_strip,
        fields={'raw': fields.StringField(index='not_analyzed')}
    )

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

Available Fields

  • Simple Fields

    • StringField(attr=None, **elasticsearch_properties)
    • FloatField(attr=None, **elasticsearch_properties)
    • DoubleField(attr=None, **elasticsearch_properties)
    • ByteField(attr=None, **elasticsearch_properties)
    • ShortField(attr=None, **elasticsearch_properties)
    • IntegerField(attr=None, **elasticsearch_properties)
    • DateField(attr=None, **elasticsearch_properties)
    • BooleanField(attr=None, **elasticsearch_properties)
    • GeoPointField(attr=None, **elasticsearch_properties)
    • GeoShapField(attr=None, **elasticsearch_properties)
    • IpField(attr=None, **elasticsearch_properties)
    • CompletionField(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

To define an Elasticsearch index you must instantiate a django_elasticsearch_dsl.Index class for set the name and settings of the index. This class inherit form elasticsearch-dsl-py Index. After you instantiate your class you need to associate it with the DocType you want to put in this Elasticsearch index.

# documents.py

from django_elasticsearch_dsl import DocType, Index
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
)


@car.doc_type
class CarDocument(DocType):
    class Meta:
        model = Car
        fields = [
            'name',
            'color',
        ]

@car.doc_type
class ManufacturerDocument(DocType):
    class Meta:
        model = Car
        fields = [
            'name', # If a field as the same name in multiple DocType of the same Index,
                    # the field type must be identical (here fields.StringField)
            'country_code',
        ]

When you execute the command:

$ ./manage.py search_index --rebuild

This will create an index named cars in elasticsearch with two mapping manufacturer_document and car_document.

Management Commands

To delete all indices in Elasticsearch or only the indices associate with a model (--models):

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

To create the indices and their mapping in Elasticsearch

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

To populate the Elasticsearch mappings with the django models data (index need to be existing)

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

To recreate and repopulate the indices you can use:

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

Settings

ELASTICSEARCH_DSL_AUTOSYNC

Default: True

Set to False to globally disable autosyncing.

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 ObjecField/NestField propeties from a DocType class.
  • Add possibility to set a default index in class DocType: class Meta index = 'cars'.
  • More examples.
  • Better ESTestCase and documentation for testing

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This is a package that allows indexing of django models in elasticsearch with elasticsearch-dsl-py.

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