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Creating Domains

Why Would You Create Domains?​

Domains are curated, top-level folders or categories where related assets can be explicitly grouped. Management of Domains can be centralized, or distributed out to Domain owners Currently, an asset can belong to only one Domain at a time. For more information about domains, refer to About DataHub Domains.

Goal Of This Guide​

This guide will show you how to create a domain named Marketing.

Prerequisites​

For this tutorial, you need to deploy DataHub Quickstart and ingest sample data. For detailed steps, please refer to Datahub Quickstart Guide.

Create Domain with GrpahQL​

::note Please note that there are two available endpoints (:8000, :9002) to access GraphQL. For more information about the differences between these endpoints, please refer to DataHub Metadata Service :::

GraphQL Explorer​

GraphQL Explorer is the fastest way to experiment with GraphQL without any dependencies. Navigate to GraphQL Explorer (http://localhost:9002/api/graphiql) and run the following query.

mutation createDomain {
  createDomain(input: { name: "Marketing", description: "Entities related to the marketing department" })
}

If you see the following response, the operation was successful:

{
  "data": {
    "createDomain": "<domain_urn>"
  },
  "extensions": {}
}

CURL​

With CURL, you need to provide tokens. To generate a token, please refer to Access Token Management. With accessToken, you can run the following command.

curl --location --request POST 'http://localhost:8080/api/graphql' \
--header 'Authorization: Bearer <my-access-token>' \
--header 'Content-Type: application/json' \
--data-raw '{ "query": "mutation createDomain { createDomain(input: { name: \"Marketing\", description: \"Entities related to the marketing department.\" }) }", "variables":{}}'

Expected Response:

{ "data": { "createDomain": "<domain_urn>" }, "extensions": {} }

Create a Domain With Python SDK​

The following code creates a domain named Marketing.

# Inlined from /metadata-ingestion/examples/library/create_domain.py
import logging

from datahub.emitter.mce_builder import make_domain_urn
from datahub.emitter.mcp import MetadataChangeProposalWrapper
from datahub.emitter.rest_emitter import DatahubRestEmitter
from datahub.metadata.schema_classes import ChangeTypeClass, DomainPropertiesClass

log = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO)

domain_urn = make_domain_urn("marketing")
domain_properties_aspect = DomainPropertiesClass(
    name="Marketing", description="Entities related to the marketing department"
)

event: MetadataChangeProposalWrapper = MetadataChangeProposalWrapper(
    entityType="domain",
    changeType=ChangeTypeClass.UPSERT,
    entityUrn=domain_urn,
    aspect=domain_properties_aspect,
)

rest_emitter = DatahubRestEmitter(gms_server="http://localhost:8080")
rest_emitter.emit(event)
log.info(f"Created domain {domain_urn}")

We're using the MetdataChangeProposalWrapper to change entities in this example. For more information about the MetadataChangeProposal, please refer to MetadataChangeProposal & MetadataChangeLog Events

Expected Outcomes​

You can now see Marketing domain has been created under Govern > Domains.

domain-created

What's Next?​

Now that you created a domain, how about enriching it? Here is a guide that you can check out.