Deployments - What If

POST https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000001/resourcegroups/my-resource-group/providers/Microsoft.Resources/deployments/my-deployment/whatIf?api-version=2025-04-01

{
  "properties": {
    "templateLink": {
      "uri": "https://example.com/exampleTemplate.json"
    },
    "parameters": {},
    "mode": "Incremental"
  }
}

import com.azure.resourcemanager.resources.models.DeploymentMode;
import com.azure.resourcemanager.resources.models.DeploymentWhatIf;
import com.azure.resourcemanager.resources.models.DeploymentWhatIfProperties;
import com.azure.resourcemanager.resources.models.TemplateLink;
import java.util.HashMap;
import java.util.Map;

/**
 * Samples for Deployments WhatIf.
 */
public final class Main {
    /*
     * x-ms-original-file:
     * specification/resources/resource-manager/Microsoft.Resources/deployments/stable/2025-04-01/examples/
     * PostDeploymentWhatIfOnResourceGroup.json
     */
    /**
     * Sample code: Predict template changes at resource group scope.
     * 
     * @param azure The entry point for accessing resource management APIs in Azure.
     */
    public static void
        predictTemplateChangesAtResourceGroupScope(com.azure.resourcemanager.AzureResourceManager azure) {
        azure.genericResources().manager().deploymentClient().getDeployments().whatIf("my-resource-group",
            "my-deployment",
            new DeploymentWhatIf().withProperties(new DeploymentWhatIfProperties()
                .withTemplateLink(new TemplateLink().withUri("https://example.com/exampleTemplate.json"))
                .withParameters(mapOf()).withMode(DeploymentMode.INCREMENTAL)),
            com.azure.core.util.Context.NONE);
    }

    // Use "Map.of" if available
    @SuppressWarnings("unchecked")
    private static <T> Map<String, T> mapOf(Object... inputs) {
        Map<String, T> map = new HashMap<>();
        for (int i = 0; i < inputs.length; i += 2) {
            String key = (String) inputs[i];
            T value = (T) inputs[i + 1];
            map.put(key, value);
        }
        return map;
    }
}

To use the Azure SDK library in your project, see this documentation. To provide feedback on this code sample, open a GitHub issue

from azure.identity import DefaultAzureCredential

from azure.mgmt.resource.deployments import DeploymentsMgmtClient

"""
# PREREQUISITES
    pip install azure-identity
    pip install azure-mgmt-resource-deployments
# USAGE
    python post_deployment_what_if_on_resource_group.py

    Before run the sample, please set the values of the client ID, tenant ID and client secret
    of the AAD application as environment variables: AZURE_CLIENT_ID, AZURE_TENANT_ID,
    AZURE_CLIENT_SECRET. For more info about how to get the value, please see:
    https://docs.microsoft.com/azure/active-directory/develop/howto-create-service-principal-portal
"""


def main():
    client = DeploymentsMgmtClient(
        credential=DefaultAzureCredential(),
        subscription_id="00000000-0000-0000-0000-000000000001",
    )

    response = client.deployments.begin_what_if(
        resource_group_name="my-resource-group",
        deployment_name="my-deployment",
        parameters={
            "properties": {
                "mode": "Incremental",
                "parameters": {},
                "templateLink": {"uri": "https://example.com/exampleTemplate.json"},
            }
        },
    ).result()
    print(response)


# x-ms-original-file: specification/resources/resource-manager/Microsoft.Resources/deployments/stable/2025-04-01/examples/PostDeploymentWhatIfOnResourceGroup.json
if __name__ == "__main__":
    main()

To use the Azure SDK library in your project, see this documentation. To provide feedback on this code sample, open a GitHub issue

package armdeployments_test

import (
	"context"
	"log"

	"github.com/Azure/azure-sdk-for-go/sdk/azcore/to"
	"github.com/Azure/azure-sdk-for-go/sdk/azidentity"
	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/resources/armdeployments"
)

// Generated from example definition: https://github.com/Azure/azure-rest-api-specs/blob/edacc3b43f9603efa119eabb6013d952d1dbe7d6/specification/resources/resource-manager/Microsoft.Resources/deployments/stable/2025-04-01/examples/PostDeploymentWhatIfOnResourceGroup.json
func ExampleClient_BeginWhatIf() {
	cred, err := azidentity.NewDefaultAzureCredential(nil)
	if err != nil {
		log.Fatalf("failed to obtain a credential: %v", err)
	}
	ctx := context.Background()
	clientFactory, err := armdeployments.NewClientFactory("<subscription-id>", cred, nil)
	if err != nil {
		log.Fatalf("failed to create client: %v", err)
	}
	poller, err := clientFactory.NewClient().BeginWhatIf(ctx, "my-resource-group", "my-deployment", armdeployments.DeploymentWhatIf{
		Properties: &armdeployments.DeploymentWhatIfProperties{
			Mode:       to.Ptr(armdeployments.DeploymentModeIncremental),
			Parameters: map[string]*armdeployments.DeploymentParameter{},
			TemplateLink: &armdeployments.TemplateLink{
				URI: to.Ptr("https://example.com/exampleTemplate.json"),
			},
		},
	}, nil)
	if err != nil {
		log.Fatalf("failed to finish the request: %v", err)
	}
	res, err := poller.PollUntilDone(ctx, nil)
	if err != nil {
		log.Fatalf("failed to pull the result: %v", err)
	}
	// You could use response here. We use blank identifier for just demo purposes.
	_ = res
	// If the HTTP response code is 200 as defined in example definition, your response structure would look as follows. Please pay attention that all the values in the output are fake values for just demo purposes.
	// res.WhatIfOperationResult = armdeployments.WhatIfOperationResult{
	// 	Properties: &armdeployments.WhatIfOperationProperties{
	// 		Changes: []*armdeployments.WhatIfChange{
	// 			{
	// 				After: map[string]any{
	// 					"name": "myExistingIdentity",
	// 					"type": "Microsoft.ManagedIdentity/userAssignedIdentities",
	// 					"apiVersion": "2018-11-30",
	// 					"id": "/subscriptions/00000000-0000-0000-0000-000000000001/resourceGroups/my-resource-group/providers/Microsoft.ManagedIdentity/userAssignedIdentities/myExistingIdentity",
	// 					"___location": "westus2",
	// 					"tags":map[string]any{
	// 						"myNewTag": "my tag value",
	// 					},
	// 				},
	// 				Before: map[string]any{
	// 					"name": "myExistingIdentity",
	// 					"type": "Microsoft.ManagedIdentity/userAssignedIdentities",
	// 					"apiVersion": "2018-11-30",
	// 					"id": "/subscriptions/00000000-0000-0000-0000-000000000001/resourceGroups/my-resource-group/providers/Microsoft.ManagedIdentity/userAssignedIdentities/myExistingIdentity",
	// 					"___location": "westus2",
	// 				},
	// 				ChangeType: to.Ptr(armdeployments.ChangeTypeModify),
	// 				Delta: []*armdeployments.WhatIfPropertyChange{
	// 					{
	// 						Path: to.Ptr("tags.myNewTag"),
	// 						After: "my tag value",
	// 						PropertyChangeType: to.Ptr(armdeployments.PropertyChangeTypeCreate),
	// 				}},
	// 				ResourceID: to.Ptr("/subscriptions/00000000-0000-0000-0000-000000000001/resourceGroups/my-resource-group/providers/Microsoft.ManagedIdentity/userAssignedIdentities/myExistingIdentity"),
	// 			},
	// 			{
	// 				After: map[string]any{
	// 					"name": "myNewIdentity",
	// 					"type": "Microsoft.ManagedIdentity/userAssignedIdentities",
	// 					"apiVersion": "2018-11-30",
	// 					"id": "/subscriptions/00000000-0000-0000-0000-000000000001/resourceGroups/my-resource-group/providers/Microsoft.ManagedIdentity/userAssignedIdentities/myNewIdentity",
	// 					"___location": "eastus",
	// 					"tags":map[string]any{
	// 						"myOtherNewTag": "another new tag value",
	// 					},
	// 				},
	// 				ChangeType: to.Ptr(armdeployments.ChangeTypeCreate),
	// 				ResourceID: to.Ptr("/subscriptions/00000000-0000-0000-0000-000000000001/resourceGroups/my-resource-group/providers/Microsoft.ManagedIdentity/userAssignedIdentities/myNewIdentity"),
	// 		}},
	// 	},
	// 	Status: to.Ptr("Succeeded"),
	// }
}

To use the Azure SDK library in your project, see this documentation. To provide feedback on this code sample, open a GitHub issue

const { DeploymentsClient } = require("@azure/arm-resourcesdeployments");
const { DefaultAzureCredential } = require("@azure/identity");
require("dotenv/config");

/**
 * This sample demonstrates how to Returns changes that will be made by the deployment if executed at the scope of the resource group.
 *
 * @summary Returns changes that will be made by the deployment if executed at the scope of the resource group.
 * x-ms-original-file: specification/resources/resource-manager/Microsoft.Resources/deployments/stable/2025-04-01/examples/PostDeploymentWhatIfOnResourceGroup.json
 */
async function predictTemplateChangesAtResourceGroupScope() {
  const subscriptionId =
    process.env["RESOURCES_SUBSCRIPTION_ID"] || "00000000-0000-0000-0000-000000000001";
  const resourceGroupName = process.env["RESOURCES_RESOURCE_GROUP"] || "my-resource-group";
  const deploymentName = "my-deployment";
  const parameters = {
    properties: {
      mode: "Incremental",
      parameters: {},
      templateLink: { uri: "https://example.com/exampleTemplate.json" },
    },
  };
  const credential = new DefaultAzureCredential();
  const client = new DeploymentsClient(credential, subscriptionId);
  const result = await client.deployments.beginWhatIfAndWait(
    resourceGroupName,
    deploymentName,
    parameters,
  );
  console.log(result);
}

To use the Azure SDK library in your project, see this documentation. To provide feedback on this code sample, open a GitHub issue