This is an example of leveraging the Microsoft.Azure.Cosmos NuGet package in a repository pattern.
The following prerequisites are required:
- NET Core 3.1 SDK
- Cosmos DB Emulator
- Azure Storage Explorer
- Visual Studio 2019, Azure Function tools are included in the Azure development workload of Visual Studio 2019
ClassLibrary1.csproj
This project contains the standard interfaces and abstract classed to support how Azure Cosmos DB should be implemented for reading and writing.
The Entity classes are for root entities, e.g. ToDo, while the ChildEntity classes are for children of root entities, e.g. ToDoComment.
From a code perspective, the main difference between Entity and ChildEntity is that ChildEntity is open to having a ParentId property which is required for most calls using the ChildEntityDataStore.
ClassLibrary1.Tests.csproj
Contains the tests for the ClassLibrary1 project.
The tests cover valid configuration options.
FunctionApp1.csproj
This project contains the concrete implementations of the ToDo and ToDoComment entities and data stores - the repositories in a repository design pattern - that are persisted to Azure Cosmos DB.
It also contains Azure Functions, and supporting classes, for CRUD operations: create, retrieve, update and delete.
FunctionApp1.Tests.csproj
Contains the tests for the FunctionApp1 project.
The tests cover reading and writing data use the EntityDataStore classes.
Currently the tests are setup to run locally using the Azure Cosmos DB Emulator.
In the FunctionApp1 project, the local.settings.json should look like:
{
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "UseDevelopmentStorage=true",
"FUNCTIONS_WORKER_RUNTIME": "dotnet",
"AzureCosmosOptions:ConnectionString": "AccountEndpoint=https://localhost:8081/;AccountKey=C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==",
"AzureCosmosOptions:DatabaseId": "YOUR_DATABASE_NAME"
}
}
In the FunctionApp1.Tests project, the appsettings.Development.json should look like:
{
"Logging": {
"LogLevel": {
"Default": "Debug",
"System": "Information",
"Microsoft": "Information"
}
},
"AzureCosmosOptions:ConnectionString": "AccountEndpoint=https://localhost:8081/;AccountKey=C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==",
"AzureCosmosOptions:DatabaseId": "YOUR_DATABASE_NAME"
}
To use Cosmos DB in Azure, update the AzureCosmosOptions:ConnectionString property with your Primary or Secondary connection strings.