Azure Schema Registry client library for Python¶
Azure Schema Registry is a schema repository service hosted by Azure Event Hubs, providing schema storage, versioning, and management. The registry is leveraged by serializers to reduce payload size while describing payload structure with schema identifiers rather than full schemas.
Source code | Package (PyPi) | API reference documentation | Samples | Changelog
Getting started¶
Install the package¶
Install the Azure Schema Registry client library and Azure Identity client library for Python with pip:
pip install azure-schemaregistry azure-identity
Prerequisites:¶
To use this package, you must have:
Azure subscription - Create a free account
Python 2.7, 3.6 or later - Install Python
Authenticate the client¶
Interaction with Schema Registry starts with an instance of SchemaRegistryClient class. You need the endpoint and AAD credential to instantiate the client object.
Create client using the azure-identity library:
from azure.schemaregistry import SchemaRegistryClient
from azure.identity import DefaultAzureCredential
credential = DefaultAzureCredential()
endpoint = '<< ENDPOINT OF THE SCHEMA REGISTRY >>'
schema_registry_client = SchemaRegistryClient(endpoint, credential)
Key concepts¶
Schema: Schema is the organization or structure for data.
SchemaRegistryClient:
SchemaRegistryClient
provides the API for storing and retrieving schemas in schema registry.
Examples¶
The following sections provide several code snippets covering some of the most common Schema Registry tasks, including:
Register a schema¶
Use SchemaRegistryClient.register_schema
method to register a schema.
When registering a schema, the Schema
and SchemaProperties
will be cached in the SchemaRegistryClient
instance, so that any subsequent calls to get_schema_id
and get_schema
corresponding to the same schema can use the cached value rather than going to the service.
import os
from azure.identity import DefaultAzureCredential
from azure.schemaregistry import SchemaRegistryClient
token_credential = DefaultAzureCredential()
endpoint = os.environ['SCHEMA_REGISTRY_ENDPOINT']
schema_group = "<your-group-name>"
schema_name = "<your-schema-name>"
serialization_type = "Avro"
schema_content = """
{"namespace": "example.avro",
"type": "record",
"name": "User",
"fields": [
{"name": "name", "type": "string"},
{"name": "favorite_number", "type": ["int", "null"]},
{"name": "favorite_color", "type": ["string", "null"]}
]
}
"""
schema_registry_client = SchemaRegistryClient(endpoint=endpoint, credential=token_credential)
with schema_registry_client:
schema_properties = schema_registry_client.register_schema(schema_group, schema_name, serialization_type, schema_content)
schema_id = schema_properties.schema_id
Get the schema by id¶
Get the schema content and its properties by schema id.
When looking up the schema content by schema id, the Schema
will be cached in the SchemaRegistryClient
instance so that subsequent requests for this schema id do not need to go the service.
import os
from azure.identity import DefaultAzureCredential
from azure.schemaregistry import SchemaRegistryClient
token_credential = DefaultAzureCredential()
endpoint = os.environ['SCHEMA_REGISTRY_ENDPOINT']
schema_id = '<your-schema-id>'
schema_registry_client = SchemaRegistryClient(endpoint=endpoint, credential=token_credential)
with schema_registry_client:
schema = schema_registry_client.get_schema(schema_id)
schema_content = schema.schema_content
Get the id of a schema¶
Get the schema id of a schema by schema content and its properties.
When looking up the schema id, the Schema
and SchemaProperties
will be cached in the SchemaRegistryClient
instance, so that subsequent requests for this schema do not need to go the service.
import os
from azure.identity import DefaultAzureCredential
from azure.schemaregistry import SchemaRegistryClient
token_credential = DefaultAzureCredential()
endpoint = os.environ['SCHEMA_REGISTRY_ENDPOINT']
schema_group = "<your-group-name>"
schema_name = "<your-schema-name>"
serialization_type = "Avro"
schema_content = """
{"namespace": "example.avro",
"type": "record",
"name": "User",
"fields": [
{"name": "name", "type": "string"},
{"name": "favorite_number", "type": ["int", "null"]},
{"name": "favorite_color", "type": ["string", "null"]}
]
}
"""
schema_registry_client = SchemaRegistryClient(endpoint=endpoint, credential=token_credential)
with schema_registry_client:
schema_properties = schema_registry_client.get_schema_id(schema_group, schema_name, serialization_type, schema_content)
schema_id = schema_properties.schema_id
Troubleshooting¶
General¶
Schema Registry clients raise exceptions defined in Azure Core.
Logging¶
This library uses the standard logging library for logging. Basic information about HTTP sessions (URLs, headers, etc.) is logged at INFO level.
Detailed DEBUG level logging, including request/response bodies and unredacted
headers, can be enabled on a client with the logging_enable
argument:
import sys
import logging
from azure.schemaregistry import SchemaRegistryClient
from azure.identity import DefaultAzureCredential
# Create a logger for the SDK
logger = logging.getLogger('azure.schemaregistry')
logger.setLevel(logging.DEBUG)
# Configure a console output
handler = logging.StreamHandler(stream=sys.stdout)
logger.addHandler(handler)
credential = DefaultAzureCredential()
# This client will log detailed information about its HTTP sessions, at DEBUG level
schema_registry_client = SchemaRegistryClient("you_end_point", credential, logging_enable=True)
Similarly, logging_enable
can enable detailed logging for a single operation,
even when it isn’t enabled for the client:
schema_registry_client.get_schema(schema_id, logging_enable=True)
Next steps¶
More sample code¶
Please take a look at the samples directory for detailed examples of how to use this library to register and retrieve schema to/from Schema Registry.
Event Hubs and Avro Serializer¶
We provide azure-schemaregistry-avroserializer library as serializer
implementation to serialize/deserialize avro data integrated with azure-schemaregistry
for automatic schema registration and retrieval.
It integrates nicely with the EventHubs SDK.
For more information and sample codes, please refer to the Azure Schema Registry Avro Serializer SDK.
Contributing¶
This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.
When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.
This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.