Azure Schema Registry Apache Avro client library for .NET
Azure Schema Registry is a schema repository service hosted by Azure Event Hubs, providing schema storage, versioning, and management. This package provides an Avro encoder capable of encoding and decoding payloads containing Schema Registry schema identifiers and Avro-encoded data.
Getting started
Install the package
Install the Azure Schema Registry Apache Avro library for .NET with NuGet:
dotnet add package Microsoft.Azure.Data.SchemaRegistry.ApacheAvro --version 1.0.0-beta.1
Prerequisites
If you need to create an Event Hubs namespace, you can use the Azure Portal or Azure PowerShell.
You can use Azure PowerShell to create the Event Hubs namespace with the following command:
New-AzEventHubNamespace -ResourceGroupName myResourceGroup -NamespaceName namespace_name -Location eastus
Authenticate the client
In order to interact with the Azure Schema Registry service, you'll need to create an instance of the Schema Registry Client class. To create this client, you'll need Azure resource credentials and the Event Hubs namespace hostname.
Get credentials
To acquire authenicated credentials and start interacting with Azure resources, please see the quickstart guide here.
Get Event Hubs namespace hostname
The simpliest way is to use the Azure portal and navigate to your Event Hubs namespace. From the Overview tab, you'll see Host name
. Copy the value from this field.
Create SchemaRegistryClient
Once you have the Azure resource credentials and the Event Hubs namespace hostname, you can create the SchemaRegistryClient. You'll also need the Azure.Identity package to create the credential.
// Create a new SchemaRegistry client using the default credential from Azure.Identity using environment variables previously set,
// including AZURE_CLIENT_ID, AZURE_CLIENT_SECRET, and AZURE_TENANT_ID.
// For more information on Azure.Identity usage, see: https://github.com/Azure/azure-sdk-for-net/blob/Microsoft.Azure.Data.SchemaRegistry.ApacheAvro_1.0.0-beta.5/sdk/identity/Azure.Identity/README.md
var schemaRegistryClient = new SchemaRegistryClient(fullyQualifiedNamespace: fullyQualifiedNamespace, credential: new DefaultAzureCredential());
Key concepts
Encoder
This library provides an encoder, [SchemaRegistryAvroEncoder]
schema_registry_avro_encoder, that interacts with EventData
events. The SchemaRegistryAvroEncoder utilizes a SchemaRegistryClient to enrich the EventData
events with the schema ID for the schema used to encode the data.
This encoder requires the Apache Avro library. The payload types accepted by this encoder include GenericRecord and ISpecificRecord.
Examples
The following shows examples of what is available through the SchemaRegistryAvroEncoder
. There are both sync and async methods available for these operations. These examples use a generated Apache Avro class Employee.cs created using this schema:
{
"type" : "record",
"namespace" : "TestSchema",
"name" : "Employee",
"fields" : [
{ "name" : "Name" , "type" : "string" },
{ "name" : "Age", "type" : "int" }
]
}
Details on generating a class using the Apache Avro library can be found in the Avro C# Documentation.
Encode and decode data using the Event Hub EventData model
In order to encode an EventData
instance with Avro information, you can do the following:
var encoder = new SchemaRegistryAvroEncoder(client, groupName, new SchemaRegistryAvroObjectEncoderOptions { AutoRegisterSchemas = true });
var employee = new Employee { Age = 42, Name = "Caketown" };
EventData eventData = await encoder.EncodeMessageDataAsync<EventData>(employee);
// the schema Id will be included as a parameter of the content type
Console.WriteLine(eventData.ContentType);
// the serialized Avro data will be stored in the EventBody
Console.WriteLine(eventData.EventBody);
To decode an EventData
event that you are consuming:
Employee deserialized = (Employee)await encoder.DecodeMessageDataAsync(eventData, typeof(Employee));
Console.WriteLine(deserialized.Age);
Console.WriteLine(deserialized.Name);
Troubleshooting
Information on troubleshooting steps will be provided as potential issues are discovered.
Next steps
See Azure Schema Registry for additional information.
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 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.