@azure/schema-registry

Azure Schema Registry client library for JavaScript

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.

Key links:

• Source code
• Package (npm)
• API Reference Documentation
• Samples

Getting started

• LTS versions of Node.js

Prerequisites

• An Azure subscription
• An existing Schema Registry resource

Install the @azure/schema-registry package

Install the Azure Schema Registry client library for JavaScript with npm:

npm install @azure/schema-registry

Create and authenticate a SchemaRegistryClient

To create a client object to access the Schema Registry API, you will need the fully qualified namespace of your Schema Registry resource and a credential. The Schema Registry client uses Azure Active Directory credentials to authenticate.

You can authenticate with Azure Active Directory using the Azure Identity library. To use the DefaultAzureCredential provider shown below, or other credential providers provided with the Azure SDK, please install the @azure/identity package:

npm install @azure/identity

Set the values of the client ID, tenant ID, and client secret of the AAD application as environment variables: AZURE_CLIENT_ID, AZURE_TENANT_ID, AZURE_CLIENT_SECRET.

const { DefaultAzureCredential } = require("@azure/identity");
const { SchemaRegistryClient } = require("@azure/schema-registry");

const client = new SchemaRegistryClient("<fullyQualifiedNamespace>", new DefaultAzureCredential());

Key concepts

SchemaRegistryClient

SchemaRegistryClient provides the API for storing and retrieving schemas in schema registry.

Examples

Register a schema

const { DefaultAzureCredential } = require("@azure/identity");
const { SchemaRegistryClient } = require("@azure/schema-registry");

const client = new SchemaRegistryClient("<fullyQualifiedNamespace>", new DefaultAzureCredential());

const description = {
  name: "<name>",
  groupName: "<group name>",
  format: "<schema format>",
  definition: "<schema definition>"
}

const registered = await client.registerSchema(description);
console.log(registered.id);

Get ID of existing schema

const { DefaultAzureCredential } = require("@azure/identity");
const { SchemaRegistryClient } = require("@azure/schema-registry");

const client = new SchemaRegistryClient("<fullyQualifiedNamespace>", new DefaultAzureCredential());

const description = {
  name: "<name>",
  groupName: "<group name>",
  format: "<schema format>",
  definition: "<schema definition>"
}

const found = await client.getSchemaProperties(description);
if (found) {
  console.log(`Got schema ID=${found.id}`);
}

Get definition of existing schema by ID

const { DefaultAzureCredential } = require("@azure/identity");
const { SchemaRegistryClient } = require("@azure/schema-registry");

const client = new SchemaRegistryClient("<fullyQualifiedNamespace>", new DefaultAzureCredential());
const foundSchema = await client.getSchema("<id>");
if (foundSchema) {
  console.log(`Got schema definition=${foundSchema.definition}`);
}

Get definition of existing schema by version

const { DefaultAzureCredential } = require("@azure/identity");
const { SchemaRegistryClient } = require("@azure/schema-registry");

const client = new SchemaRegistryClient("<fullyQualifiedNamespace>", new DefaultAzureCredential());
const foundSchema = await client.getSchema("<schema name>", "<group name>", version);
if (foundSchema) {
  console.log(`Got schema definition=${foundSchema.definition}`);
}

Troubleshooting

Logging

Enabling logging may help uncover useful information about failures. In order to see a log of HTTP requests and responses, set the AZURE_LOG_LEVEL environment variable to info. Alternatively, logging can be enabled at runtime by calling setLogLevel in the @azure/logger:

const { setLogLevel } = require("@azure/logger");

setLogLevel("info");

Next steps

Please take a look at the samples directory for detailed examples on how to use this library.

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 [e-mail] with any additional questions or comments.

If you'd like to contribute to this library, please read the contributing guide to learn more about how to build and test the code.

Related projects

• Microsoft Azure SDK for Javascript