Adding Managed Identity support for connecting to Cosmos DB, Update dependencies with latest.

README.md

@@ -55,7 +55,7 @@ The external scaler calls Cosmos DB APIs to estimate the amount of changes pendi
 
 Create `ScaledObject` resource that contains the information about your application (the scale target), the external scaler service, Cosmos DB containers, and other scaling configuration values. Check [`ScaledObject` specification](https://keda.sh/docs/concepts/scaling-deployments/) and [`External` trigger specification](https://keda.sh/docs/scalers/external/) for information on different properties supported for `ScaledObject` and their allowed values.
 
-You can use file `deploy/deploy-scaledobject.yaml` as a template for creating the `ScaledObject`. The trigger metadata properties required to use the external scaler for Cosmos DB are described in [Trigger Specification](#trigger-specification) section below.
+You can use the `deploy/deploy-scaledobject.yaml` file as a template for creating the `ScaledObject` when connecting to Cosmos DB with a managed identity. If you are using a connection string for the connection, use the `deploy/deploy-scaledobject-cs.yaml` file as your template instead. The trigger metadata properties required to use the external scaler for Cosmos DB are described in [Trigger Specification](#trigger-specification) section below.
 
 > **Note:** If you are having trouble setting up the external scaler or the listener application, the step-by-step instructions for [deploying the sample application](./src/Scaler.Demo/README.md) might help.
 
@@ -68,10 +68,10 @@ The specification below describes the `trigger` metadata in `ScaledObject` resou
     - type: external
       metadata:
         scalerAddress: external-scaler-azure-cosmos-db.keda:4050 # Mandatory. Address of the external scaler service.
-        connection: <connection>               # Mandatory. Connection string of Cosmos DB account with monitored container.
+        endpoint: <endpoint>                   # Mandatory. Endpoint URL of Cosmos DB account with monitored container.
         databaseId: <database-id>              # Mandatory. ID of Cosmos DB database containing monitored container.
         containerId: <container-id>            # Mandatory. ID of monitored container.
-        leaseConnection: <lease-connection>    # Mandatory. Connection string of Cosmos DB account with lease container.
+        leaseEndpoint: <lease-endpoint>        # Mandatory. Endpoint URL of Cosmos DB account with lease container.
         leaseDatabaseId: <lease-database-id>   # Mandatory. ID of Cosmos DB database containing lease container.
         leaseContainerId: <lease-container-id> # Mandatory. ID of lease container.
         processorName: <processor-name>        # Mandatory. Name of change-feed processor used by listener application.
@@ -81,13 +81,13 @@ The specification below describes the `trigger` metadata in `ScaledObject` resou
 
 - **`scalerAddress`** - Address of the external scaler service. This would be in format `<scaler-name>.<scaler-namespace>:<port>`. If you installed Azure Cosmos DB external scaler Helm chart in `keda` namespace and did not specify custom values, the metadata value would be `external-scaler-azure-cosmos-db.keda:4050`.
 
-- **`connection`** - Connection string of the Cosmos DB account that contains the monitored container.
+- **`endpoint`** - Endpoint URL of the Cosmos DB account that contains the monitored container.
 
 - **`databaseId`** - ID of Cosmos DB database that contains the monitored container.
 
 - **`containerId`** - ID of the monitored container.
 
-- **`leaseConnection`** - Connection string of the Cosmos DB account that contains the lease container. This can be same or different from the value of `connection` metadata.
+- **`leaseEndpoint`** - Endpoint URL of the Cosmos DB account that contains the lease container. This can be same or different from the value of `endpoint` metadata.
 
 - **`leaseDatabaseId`** - ID of Cosmos DB database that contains the lease container. This can be same or different from the value of `databaseId` metadata.
 

deploy/deploy-scaledobject-cs.yaml

@@ -0,0 +1,22 @@
+# Template scaled-object for using KEDA external scaler for Azure Cosmos DB.
+
+apiVersion: keda.sh/v1alpha1
+kind: ScaledObject
+metadata:
+  name: <scaledobject-name>
+  namespace: default
+spec:
+  pollingInterval: 20
+  scaleTargetRef:
+    name: <application-deployment-name>
+  triggers:
+    - type: external
+      metadata:
+        scalerAddress: external-scaler-azure-cosmos-db.keda:4050
+        connection: <connection-string-of-monitored-container-account>
+        databaseId: <database-id>
+        containerId: <container-id>
+        leaseConnection: <connection-string-of-lease-container-account>
+        leaseDatabaseId: <lease-database-id>
+        leaseContainerId: <lease-container-id>
+        processorName: <processor-name>

deploy/deploy-scaledobject.yaml

@@ -13,10 +13,10 @@ spec:
     - type: external
       metadata:
         scalerAddress: external-scaler-azure-cosmos-db.keda:4050
-        connection: <connection-string-of-monitored-container-account>
+        endpoint: <endpoint-url-of-monitored-container-account>
         databaseId: <database-id>
         containerId: <container-id>
-        leaseConnection: <connection-string-of-lease-container-account>
+        leaseEndpoint: <endpoint-url-of-lease-container-account>
         leaseDatabaseId: <lease-database-id>
         leaseContainerId: <lease-container-id>
         processorName: <processor-name>

src/Scaler.Demo/OrderGenerator/Dockerfile

@@ -1,16 +1,23 @@
-# https://hub.docker.com/_/microsoft-dotnet
+#See https://aka.ms/customizecontainer to learn how to customize your debug container and how Visual Studio uses this Dockerfile to build your images for faster debugging.
+
+FROM mcr.microsoft.com/dotnet/runtime:6.0 AS base
+WORKDIR /app
 
-# Restore, build and publish project.
 FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
-WORKDIR /
-COPY src/Scaler.Demo/OrderGenerator/ src/Scaler.Demo/OrderGenerator/
-COPY src/Scaler.Demo/Shared/ src/Scaler.Demo/Shared/
+ARG BUILD_CONFIGURATION=Release
+WORKDIR /src
+COPY ["Scaler.Demo/OrderGenerator/Keda.CosmosDb.Scaler.Demo.OrderGenerator.csproj", "Scaler.Demo/OrderGenerator/"]
+COPY ["Scaler.Demo/Shared/Keda.CosmosDb.Scaler.Demo.Shared.csproj", "Scaler.Demo/Shared/"]
+RUN dotnet restore "./Scaler.Demo/OrderGenerator/Keda.CosmosDb.Scaler.Demo.OrderGenerator.csproj"
+COPY . .
+WORKDIR "/src/Scaler.Demo/OrderGenerator"
+RUN dotnet build "./Keda.CosmosDb.Scaler.Demo.OrderGenerator.csproj" -c $BUILD_CONFIGURATION -o /app/build
 
-WORKDIR /src/Scaler.Demo/OrderGenerator
-RUN dotnet publish --configuration Release --output /app
+FROM build AS publish
+ARG BUILD_CONFIGURATION=Release
+RUN dotnet publish "./Keda.CosmosDb.Scaler.Demo.OrderGenerator.csproj" -c $BUILD_CONFIGURATION -o /app/publish /p:UseAppHost=false
 
-# Stage application.
-FROM mcr.microsoft.com/dotnet/runtime:6.0
+FROM base AS final
 WORKDIR /app
-COPY --from=build /app .
-ENTRYPOINT ["dotnet", "Keda.CosmosDb.Scaler.Demo.OrderGenerator.dll"]
+COPY --from=publish /app/publish .
+ENTRYPOINT ["dotnet", "Keda.CosmosDb.Scaler.Demo.OrderGenerator.dll"]

src/Scaler.Demo/OrderGenerator/Keda.CosmosDb.Scaler.Demo.OrderGenerator.csproj

@@ -1,21 +1,20 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
+<Project Sdk="Microsoft.NET.Sdk;Microsoft.NET.Sdk.Publish">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>net6.0</TargetFramework>
+    <DockerDefaultTargetOS>Linux</DockerDefaultTargetOS>
+    <DockerfileContext>..\..</DockerfileContext>
   </PropertyGroup>
-
   <ItemGroup>
-    <PackageReference Include="Bogus" Version="34.0.2" />
+    <PackageReference Include="Bogus" Version="35.5.1" />
     <PackageReference Include="Microsoft.Azure.Cosmos" Version="3.40.0" />
-    <PackageReference Include="Microsoft.Extensions.Hosting" Version="6.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.0" />
+    <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.20.1" />
   </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\Shared\Keda.CosmosDb.Scaler.Demo.Shared.csproj" />
   </ItemGroup>
-
   <ItemGroup>
     <None Include="appsettings.json" CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
-</Project>
+</Project>

src/Scaler.Demo/OrderGenerator/appsettings.json

@@ -1,6 +1,7 @@
 {
   "CosmosDbConfig": {
-    "Connection": "<connection-string-of-monitored-container-account>",
+    "Endpoint": "https://{Cosmos Account Name}.documents.azure.com:443/",
+    "Connection": "<Delete this line if using managed identity to connect to Cosmos DB, else update with connection-string-of-monitored-container-account>",
     "DatabaseId": "StoreDatabase",
     "ContainerId": "OrderContainer",
     "ContainerThroughput": 11000

src/Scaler.Demo/OrderProcessor/Dockerfile

@@ -1,16 +1,23 @@
-# https://hub.docker.com/_/microsoft-dotnet
+#See https://aka.ms/customizecontainer to learn how to customize your debug container and how Visual Studio uses this Dockerfile to build your images for faster debugging.
+
+FROM mcr.microsoft.com/dotnet/runtime:6.0 AS base
+WORKDIR /app
 
-# Restore, build and publish project.
 FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
-WORKDIR /
-COPY src/Scaler.Demo/OrderProcessor/ src/Scaler.Demo/OrderProcessor/
-COPY src/Scaler.Demo/Shared/ src/Scaler.Demo/Shared/
+ARG BUILD_CONFIGURATION=Release
+WORKDIR /src
+COPY ["Scaler.Demo/OrderProcessor/Keda.CosmosDb.Scaler.Demo.OrderProcessor.csproj", "Scaler.Demo/OrderProcessor/"]
+COPY ["Scaler.Demo/Shared/Keda.CosmosDb.Scaler.Demo.Shared.csproj", "Scaler.Demo/Shared/"]
+RUN dotnet restore "./Scaler.Demo/OrderProcessor/Keda.CosmosDb.Scaler.Demo.OrderProcessor.csproj"
+COPY . .
+WORKDIR "/src/Scaler.Demo/OrderProcessor"
+RUN dotnet build "./Keda.CosmosDb.Scaler.Demo.OrderProcessor.csproj" -c $BUILD_CONFIGURATION -o /app/build
 
-WORKDIR /src/Scaler.Demo/OrderProcessor
-RUN dotnet publish --configuration Release --output /app
+FROM build AS publish
+ARG BUILD_CONFIGURATION=Release
+RUN dotnet publish "./Keda.CosmosDb.Scaler.Demo.OrderProcessor.csproj" -c $BUILD_CONFIGURATION -o /app/publish /p:UseAppHost=false
 
-# Stage application.
-FROM mcr.microsoft.com/dotnet/runtime:6.0
+FROM base AS final
 WORKDIR /app
-COPY --from=build /app .
-ENTRYPOINT ["dotnet", "Keda.CosmosDb.Scaler.Demo.OrderProcessor.dll"]
+COPY --from=publish /app/publish .
+ENTRYPOINT ["dotnet", "Keda.CosmosDb.Scaler.Demo.OrderProcessor.dll"]

src/Scaler.Demo/OrderProcessor/Keda.CosmosDb.Scaler.Demo.OrderProcessor.csproj

@@ -2,12 +2,16 @@
 
   <PropertyGroup>
     <TargetFramework>net6.0</TargetFramework>
+    <DockerDefaultTargetOS>Linux</DockerDefaultTargetOS>
+    <DockerfileContext>..\..</DockerfileContext>
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Azure.Identity" Version="1.11.4" />
     <PackageReference Include="Microsoft.Azure.Cosmos" Version="3.40.0" />
-    <PackageReference Include="Microsoft.Extensions.Hosting" Version="6.0.1" />
-    <PackageReference Include="Microsoft.Extensions.Logging" Version="6.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Logging" Version="8.0.0" />
+    <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.20.1" />
   </ItemGroup>
 
   <ItemGroup>

src/Scaler.Demo/OrderProcessor/Worker.cs

@@ -7,6 +7,8 @@
 using Microsoft.Azure.Cosmos;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
+using Azure.Identity;
+using static Azure.Core.HttpHeader;
 
 namespace Keda.CosmosDb.Scaler.Demo.OrderProcessor
 {
@@ -25,8 +27,49 @@ public Worker(CosmosDbConfig cosmosDbConfig, ILogger<Worker> logger)
 
         public override async Task StartAsync(CancellationToken cancellationToken)
         {
-            Database leaseDatabase = await new CosmosClient(_cosmosDbConfig.LeaseConnection)
-                .CreateDatabaseIfNotExistsAsync(_cosmosDbConfig.LeaseDatabaseId, cancellationToken: cancellationToken);
+            Database leaseDatabase;
+            CosmosClient cosmosClient;
+
+            if (string.IsNullOrEmpty(_cosmosDbConfig.Connection))
+            {
+                var credential = new DefaultAzureCredential();
+
+                cosmosClient = new Microsoft.Azure.Cosmos.CosmosClient(_cosmosDbConfig.Endpoint, credential);
+            }
+            else
+            {
+                cosmosClient = new Microsoft.Azure.Cosmos.CosmosClient(_cosmosDbConfig.Connection);
+            }
+
+            //use connection string or credentials
+            if (string.IsNullOrEmpty(_cosmosDbConfig.LeaseConnection))
+            {
+
+                // maintain a single instance of CosmosClient per lifetime of the application.
+                if (_cosmosDbConfig.LeaseEndpoint == _cosmosDbConfig.Endpoint)
+                {
+                    leaseDatabase = await cosmosClient.CreateDatabaseIfNotExistsAsync(_cosmosDbConfig.LeaseDatabaseId);
+                }
+                else
+                {
+                    var credential = new DefaultAzureCredential();
+                    leaseDatabase = await new Microsoft.Azure.Cosmos.CosmosClient(_cosmosDbConfig.LeaseEndpoint, credential)
+                        .CreateDatabaseIfNotExistsAsync(_cosmosDbConfig.LeaseDatabaseId); 
+                }
+            }
+            else
+            {
+                // maintain a single instance of CosmosClient per lifetime of the application.
+                if (_cosmosDbConfig.LeaseConnection == _cosmosDbConfig.Connection)
+                {
+                    leaseDatabase = await cosmosClient.CreateDatabaseIfNotExistsAsync(_cosmosDbConfig.LeaseDatabaseId);
+                }
+                else
+                {
+                    leaseDatabase = await new Microsoft.Azure.Cosmos.CosmosClient(_cosmosDbConfig.LeaseConnection)
+                         .CreateDatabaseIfNotExistsAsync(_cosmosDbConfig.LeaseDatabaseId);
+                }
+            }
 
             Container leaseContainer = await leaseDatabase
                 .CreateContainerIfNotExistsAsync(
@@ -37,7 +80,8 @@ public override async Task StartAsync(CancellationToken cancellationToken)
             // Change feed processor instance name should be unique for each container application.
             string instanceName = $"Instance-{Dns.GetHostName()}";
 
-            _processor = new CosmosClient(_cosmosDbConfig.Connection)
+
+            _processor = cosmosClient
                 .GetContainer(_cosmosDbConfig.DatabaseId, _cosmosDbConfig.ContainerId)
                 .GetChangeFeedProcessorBuilder<Order>(_cosmosDbConfig.ProcessorName, ProcessOrdersAsync)
                 .WithInstanceName(instanceName)

src/Scaler.Demo/OrderProcessor/appsettings.json

@@ -7,10 +7,8 @@
     }
   },
   "CosmosDbConfig": {
-    "Connection": "<connection-string-of-monitored-container-account>",
     "DatabaseId": "StoreDatabase",
     "ContainerId": "OrderContainer",
-    "LeaseConnection": "<connection-string-of-lease-container-account>",
     "LeaseDatabaseId": "StoreDatabase",
     "LeaseContainerId": "OrderProcessorLeases",
     "ProcessorName": "OrderProcessor"

src/Scaler.Demo/OrderProcessor/deploy-cs.yaml

@@ -0,0 +1,26 @@
+# Deploy order processor application.
+
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: cosmosdb-order-processor
+  namespace: default
+spec:
+  replicas: 1 # A replica is required to be up momentarily to initialize the change-feed.
+  selector:
+    matchLabels:
+      app: cosmosdb-order-processor
+  template:
+    metadata:
+      labels:
+        app: cosmosdb-order-processor
+    spec:
+      containers:
+        - name: cosmosdb-order-processor
+          image: <docker-id>/cosmosdb-order-processor:latest
+          imagePullPolicy: Always
+          env:
+            - name: CosmosDbConfig__Connection
+              value: <connection-string-of-monitored-container>
+            - name: CosmosDbConfig__LeaseConnection
+              value: <connection-string-of-lease-container>

src/Scaler.Demo/OrderProcessor/deploy-scaledobject-cs.yaml

@@ -0,0 +1,22 @@
+# Create KEDA scaled object to scale order processor application.
+
+apiVersion: keda.sh/v1alpha1
+kind: ScaledObject
+metadata:
+  name: cosmosdb-order-processor-scaledobject
+  namespace: default
+spec:
+  pollingInterval: 20
+  scaleTargetRef:
+    name: cosmosdb-order-processor
+  triggers:
+    - type: external
+      metadata:
+        scalerAddress: cosmosdb-scaler.default:4050
+        connection: <connection-string-of-monitored-container-account>
+        databaseId: StoreDatabase
+        containerId: OrderContainer
+        leaseConnection: <connection-string-of-lease-container-account>
+        leaseDatabaseId: StoreDatabase
+        leaseContainerId: OrderProcessorLeases
+        processorName: OrderProcessor

src/Scaler.Demo/OrderProcessor/deploy-scaledobject.yaml

@@ -13,10 +13,10 @@ spec:
     - type: external
       metadata:
         scalerAddress: cosmosdb-scaler.default:4050
-        connection: <connection-string-of-monitored-container-account>
+        endpoint: <endpoint-url-for-cosmosdb-account-monitored-container>
         databaseId: StoreDatabase
         containerId: OrderContainer
-        leaseConnection: <connection-string-of-lease-container-account>
+        leaseEndpoint: <endpoint-url-for-cosmosdb-account-lease-container>
         leaseDatabaseId: StoreDatabase
         leaseContainerId: OrderProcessorLeases
         processorName: OrderProcessor

src/Scaler.Demo/OrderProcessor/deploy.yaml

@@ -5,6 +5,9 @@ kind: Deployment
 metadata:
   name: cosmosdb-order-processor
   namespace: default
+  labels:
+    aadpodidbinding: "my-pod-identity"  # refer to https://learn.microsoft.com/en-us/azure/aks/use-azure-ad-pod-identity#create-a-pod-identity
+    app: cosmosdb-order-processor	
 spec:
   replicas: 1 # A replica is required to be up momentarily to initialize the change-feed.
   selector:
@@ -14,13 +17,14 @@ spec:
     metadata:
       labels:
         app: cosmosdb-order-processor
+        aadpodidbinding: "my-pod-identity"  # refer to https://learn.microsoft.com/en-us/azure/aks/use-azure-ad-pod-identity#create-a-pod-identity
     spec:
       containers:
         - name: cosmosdb-order-processor
           image: <docker-id>/cosmosdb-order-processor:latest
           imagePullPolicy: Always
           env:
-            - name: CosmosDbConfig__Connection
-              value: <connection-string-of-monitored-container>
-            - name: CosmosDbConfig__LeaseConnection
-              value: <connection-string-of-lease-container>
+            - name: CosmosDbConfig__Endpoint
+              value: <endpoint-URL-of-cosmos-DB-account-monitored-container>
+            - name: CosmosDbConfig__LeaseEndpoint
+              value: <endpoint-URL-of-cosmos-DB-account-lease-container>