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Azure Cosmos DB

React to document changes and read/write items with Azure Cosmos DB bindings in PowerShell.

Change Feed Trigger

function.json:

{
  "bindings": [
    {
      "name": "Documents",
      "type": "cosmosDBTrigger",
      "direction": "in",
      "databaseName": "catalog",
      "containerName": "products",
      "connection": "CosmosDbConnection",
      "leaseContainerName": "leases",
      "createLeaseContainerIfNotExists": true
    }
  ]
}

run.ps1:

param($Documents, $TriggerMetadata)

Write-Information "Change feed delivered $($Documents.Count) document(s)"
foreach ($doc in $Documents) {
    Write-Information "Changed document id: $($doc.id)"
}

The trigger uses a lease container to track its position in the change feed. Keep the lease container in the same account as the monitored container.

Input Binding

Read a single item by id and partition key:

{
  "name": "Product",
  "type": "cosmosDB",
  "direction": "in",
  "databaseName": "catalog",
  "containerName": "products",
  "connection": "CosmosDbConnection",
  "id": "{Query.id}",
  "partitionKey": "{Query.category}"
}

Output Binding

{
  "name": "OutputDocument",
  "type": "cosmosDB",
  "direction": "out",
  "databaseName": "catalog",
  "containerName": "products",
  "connection": "CosmosDbConnection"
}

Push-OutputBinding -Name OutputDocument -Value @{ id = [guid]::NewGuid().ToString(); category = "books"; name = "Sample" }

Identity-based connections

Configure CosmosDbConnection__accountEndpoint with a managed identity instead of an account key. See Managed Identity.

See Also

Sources