multi-tenant-by-database

Azure Cosmos DB Spring Data - Multi Tenant by Database

Spring Data Cosmos sample for a multi-tenanted app where each tenant has its own Azure Cosmos DB database.

• This sample only work with Spring Boot 3 This sample application fetches the value of the tenant from request header (TenantId). In a real-world application, it is up to you how to identify this while keeping your application secure. For example, you may want to fetch the identifier from a cookie, or other header name. The approach of assigning a database (or container) to each tenant may be useful if it is necessary to strictly isolate performance for each tenant. However, you should consider the trade-offs in taking this approach. Review our article on Multitenancy and Azure Cosmos DB for more guidance.

Note: this is a contrived sample in terms of the data model, and does not reflect any recommendations for how to model any application in particular. It is intended purely to illustrate how to maintain a database-per-tenant isolation model using Spring Data for Azure Cosmos DB, where databases for each tenant are created/referenced dynamically (on-the-fly) rather than being hardcoded at project startup.

Prerequisites

• Java Development Kit 8.
• Apache Maven.

Create Azure Resources

• Create an active Azure account. If you don't have one, you can sign up for a free account. Alternatively, you can use the Azure Cosmos DB Emulator for development and testing. As emulator https certificate is self signed, you need to import its certificate to java trusted cert store, explained here.

Update environment variables

1. The app uses environment variables ACCOUNT_HOST and ACCOUNT_KEY. Make sure these environment variables exist, and are set to your Azure Cosmos DB account URI and PRIMARY KEY respectively.

Run application

1. git clone https://github.com/Azure-Samples/azure-spring-boot-samples.git
2. cd cosmos/azure-spring-data-cosmos/cosmos-multi-tenant-samples/tenant-by-database
3. start the application: mvn spring-boot:run
4. Send a request to the web service from a linux based command line to create a user, setting the value of TenantId differently for each tenant (or you can use postman): curl -s -d '{"firstName":"Theo","lastName":"van Kraay"}' -H "Content-Type: application/json" -H "TenantId: theo" -X POST http://localhost:8080/users
5. Create an Order: curl -s -d '{"orderDetail":"Order no.1","lastName":"van Kraay"}' -H "Content-Type: application/json" -H "TenantId: theo" -X POST http://localhost:8080/orders
6. You should see databases named by each tenant created in Cosmos DB, each containing User and Order containers.

Sample Investigation

• The application is a simple CRUD REST web service which creates User and Order entries in each tenant, and makes use of azure-spring-data-cosmos for Azure Cosmos DB NoSQL API.
• The application captures a http request header of TenantId. This is used to check if the corresponding tenant database exists, or needs to be created. The Java classes with functionality for capturing tenant id, and referencing and/or creating tenant databases by tenant id, are in the tenant folder.
• If a tenant database does not exist, the MultiTenantDBCosmosFactory class overrides getDatabaseName() in CosmosFactory to allow different tenant databases to be created and/or referenced on the fly, while still allowing native Spring Repository APIs to query their entities.
• CRUD operations are performed in UserController and OrderController using corresponding Spring Repository APIs.

Next Steps

Please refer to azure spring data cosmos for sql api source code for more information.