CosmosDB

This connector simplifies using Azure Cosmos DB in an application running on Cloud Foundry. The connector is built to work with Azure Cosmos DB service instances that have been provisioned using the Microsoft Azure Service Broker, where from either Microsoft.Azure.Cosmos or the newer package Azure.Cosmos.

Usage

To use this connector:

1. Create a Cosmos DB Service instance and bind it to your application.
2. Optionally, configure any CosmosDB client settings.
3. Add the Steeltoe Cloud Foundry configuration provider to your ConfigurationBuilder.

Add NuGet References

To use the CosmosDB connector, add either Microsoft.Azure.Cosmos or Azure.Cosmos (pre-release only as of this writing) as you would if you weren't using Steeltoe. Then, add a reference to the appropriate Steeltoe Connector NuGet package

Configure Settings

This connector supports several settings for local interaction with CosmosDB that will be overridden by service bindings on deployment:

{
  "cosmosdb": {
    "client": {
      "host": "https://localhost:8081",
      "masterKey": "<yourMasterKeyHere>"
    }
  }
}

The following table table describes all possible settings for the connector

Key	Description	Default
host	Protocol, hostname or IP Address and port of the server	not set
masterKey	Authentication for read/write access	not set
readOnlyKey	Authentication for read-only access	not set
databaseId	Name of the database to use	not set
useReadOnlyCredentials	Designate that the read-only key should be used	false
connectionString	Full connection string	built from settings
urlEncodedCredentials	Set to true if your service broker provides URL-encoded credentials	false

IMPORTANT: All of these settings should be prefixed with cosmosdb:client:.

The samples and most templates are already set up to read from appsettings.json.

NOTE: If a ConnectionString is provided and VCAP_SERVICES are not detected (a typical scenario for local app development), the ConnectionString will be used exactly as provided.

Cloud Foundry

To use CosmosDB on Cloud Foundry, create and bind an instance to your application by using the Cloud Foundry CLI, as shown in the following example:

# Create CosmosDB service
cf create-service azure-cosmosdb standard myCosmosDb

# Bind service to `myApp`
cf bind-service myApp myCosmosDb

# Restage the app to pick up change
cf restage myApp

Use CosmosClient

Use Steeltoe's ConnectionStringManager to access connection information built by combining your cosmosdb:client settings with credentials from service bindings (when present) and create a new CosmosClient:

// read settings from "cosmosdb:client" and VCAP:services or services:
var configMgr = new ConnectionStringManager(configuration);
var cosmosInfo = configMgr.Get<CosmosDbConnectionInfo>();

// these are mapped into the properties dictionary
var databaseName = cosmosInfo.Properties["DatabaseId"];
var databaseLink = cosmosInfo.Properties["DatabaseLink"];

// container is not provided by a service binding, use your own config value to store it:
var containerName = configuration.GetValue<string>("CosmosDb:Container");
var cosmosClient = new CosmosClient(cosmosInfo.ConnectionString);