refactor(cli): hotswap is now a deployment method (#519)

mrgrain · web-flow · commit 841bc03760b3 · 2025-05-23T15:11:10.000Z
Follow-up from #517 to make the same changes to the CLI. This has no user impact. --- By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license
diff --git a/packages/aws-cdk/lib/cli/cdk-toolkit.ts b/packages/aws-cdk/lib/cli/cdk-toolkit.ts
@@ -20,7 +20,6 @@ import type { BootstrapEnvironmentOptions } from '../api/bootstrap';
 import { Bootstrapper } from '../api/bootstrap';
 import { ExtendedStackSelection, StackCollection } from '../api/cloud-assembly';
 import type { Deployments, SuccessfulDeployStackResult } from '../api/deployments';
-import { EcsHotswapProperties, HotswapMode, HotswapPropertyOverrides } from '../api/hotswap';
 import { type Tag, tagsForStack } from '../api/tags';
 import { StackActivityProgress } from '../commands/deploy';
 import { listStacks } from '../commands/list-stacks';
@@ -374,23 +373,13 @@ export class CdkToolkit {
 
     const parameterMap = buildParameterMap(options.parameters);
 
-    if (options.hotswap !== HotswapMode.FULL_DEPLOYMENT) {
+    if (options.deploymentMethod?.method === 'hotswap') {
       warning(
         '⚠️ The --hotswap and --hotswap-fallback flags deliberately introduce CloudFormation drift to speed up deployments',
       );
       warning('⚠️ They should only be used for development - never use them for your production Stacks!\n');
     }
 
-    let hotswapPropertiesFromSettings = this.props.configuration.settings.get(['hotswap']) || {};
-
-    let hotswapPropertyOverrides = new HotswapPropertyOverrides(
-      new EcsHotswapProperties(
-        hotswapPropertiesFromSettings.ecs?.minimumHealthyPercent,
-        hotswapPropertiesFromSettings.ecs?.maximumHealthyPercent,
-        hotswapPropertiesFromSettings.ecs?.stabilizationTimeoutSeconds,
-      ),
-    );
-
     const stacks = stackCollection.stackArtifacts;
 
     const stackOutputs: { [key: string]: any } = {};
@@ -518,8 +507,6 @@ export class CdkToolkit {
             parameters: Object.assign({}, parameterMap['*'], parameterMap[stack.stackName]),
             usePreviousParameters: options.usePreviousParameters,
             rollback,
-            hotswap: options.hotswap,
-            hotswapPropertyOverrides: hotswapPropertyOverrides,
             extraUserAgent: options.extraUserAgent,
             assetParallelism: options.assetParallelism,
             ignoreNoStacks: options.ignoreNoStacks,
@@ -1403,8 +1390,7 @@ export class CdkToolkit {
       watch: false,
       cloudWatchLogMonitor,
       cacheCloudAssembly: false,
-      hotswap: options.hotswap,
-      extraUserAgent: `cdk-watch/hotswap-${options.hotswap !== HotswapMode.FALL_BACK ? 'on' : 'off'}`,
+      extraUserAgent: `cdk-watch/hotswap-${options.deploymentMethod?.method === 'hotswap' ? 'on' : 'off'}`,
       concurrency: options.concurrency,
     };
 
@@ -1603,15 +1589,6 @@ interface WatchOptions extends Omit<CfnDeployOptions, 'execute'> {
    */
   force?: boolean;
 
-  /**
-   * Whether to perform a 'hotswap' deployment.
-   * A 'hotswap' deployment will attempt to short-circuit CloudFormation
-   * and update the affected resources like Lambda functions directly.
-   *
-   * @default - `HotswapMode.FALL_BACK` for regular deployments, `HotswapMode.HOTSWAP_ONLY` for 'watch' deployments
-   */
-  readonly hotswap: HotswapMode;
-
   /**
    * The extra string to append to the User-Agent header when performing AWS SDK calls.
    *
diff --git a/packages/aws-cdk/lib/cli/cli.ts b/packages/aws-cdk/lib/cli/cli.ts
@@ -1,6 +1,6 @@
 /* eslint-disable @typescript-eslint/no-shadow */ // yargs
 import * as cxapi from '@aws-cdk/cx-api';
-import type { DeploymentMethod } from '@aws-cdk/toolkit-lib';
+import type { ChangeSetDeployment, DeploymentMethod, DirectDeployment } from '@aws-cdk/toolkit-lib';
 import { ToolkitError } from '@aws-cdk/toolkit-lib';
 import * as chalk from 'chalk';
 import { CdkToolkit, AssetBuildTime } from './cdk-toolkit';
@@ -322,43 +322,6 @@ export async function exec(args: string[], synthesizer?: Synthesizer): Promise<n
           throw new ToolkitError('Can not supply both --[no-]execute and --method at the same time');
         }
 
-        let deploymentMethod: DeploymentMethod | undefined;
-        switch (args.method) {
-          case 'direct':
-            if (args.changeSetName) {
-              throw new ToolkitError('--change-set-name cannot be used with method=direct');
-            }
-            if (args.importExistingResources) {
-              throw new ToolkitError('--import-existing-resources cannot be enabled with method=direct');
-            }
-            deploymentMethod = { method: 'direct' };
-            break;
-          case 'change-set':
-            deploymentMethod = {
-              method: 'change-set',
-              execute: true,
-              changeSetName: args.changeSetName,
-              importExistingResources: args.importExistingResources,
-            };
-            break;
-          case 'prepare-change-set':
-            deploymentMethod = {
-              method: 'change-set',
-              execute: false,
-              changeSetName: args.changeSetName,
-              importExistingResources: args.importExistingResources,
-            };
-            break;
-          case undefined:
-            deploymentMethod = {
-              method: 'change-set',
-              execute: args.execute ?? true,
-              changeSetName: args.changeSetName,
-              importExistingResources: args.importExistingResources,
-            };
-            break;
-        }
-
         return cli.deploy({
           selector,
           exclusively: args.exclusively,
@@ -368,15 +331,14 @@ export async function exec(args: string[], synthesizer?: Synthesizer): Promise<n
           requireApproval: configuration.settings.get(['requireApproval']),
           reuseAssets: args['build-exclude'],
           tags: configuration.settings.get(['tags']),
-          deploymentMethod,
+          deploymentMethod: determineDeploymentMethod(args, configuration),
           force: args.force,
           parameters: parameterMap,
           usePreviousParameters: args['previous-parameters'],
           outputsFile: configuration.settings.get(['outputsFile']),
           progress: configuration.settings.get(['progress']),
           ci: args.ci,
           rollback: configuration.settings.get(['rollback']),
-          hotswap: determineHotswapMode(args.hotswap, args.hotswapFallback),
           watch: args.watch,
           traceLogs: args.logs,
           concurrency: args.concurrency,
@@ -424,14 +386,10 @@ export async function exec(args: string[], synthesizer?: Synthesizer): Promise<n
           toolkitStackName,
           roleArn: args.roleArn,
           reuseAssets: args['build-exclude'],
-          deploymentMethod: {
-            method: 'change-set',
-            changeSetName: args.changeSetName,
-          },
+          deploymentMethod: determineDeploymentMethod(args, configuration, true),
           force: args.force,
           progress: configuration.settings.get(['progress']),
           rollback: configuration.settings.get(['rollback']),
-          hotswap: determineHotswapMode(args.hotswap, args.hotswapFallback, true),
           traceLogs: args.logs,
           concurrency: args.concurrency,
         });
@@ -565,6 +523,65 @@ function arrayFromYargs(xs: string[]): string[] | undefined {
   return xs.filter((x) => x !== '');
 }
 
+function determineDeploymentMethod(args: any, configuration: Configuration, watch?: boolean): DeploymentMethod {
+  let deploymentMethod: ChangeSetDeployment | DirectDeployment | undefined;
+  switch (args.method) {
+    case 'direct':
+      if (args.changeSetName) {
+        throw new ToolkitError('--change-set-name cannot be used with method=direct');
+      }
+      if (args.importExistingResources) {
+        throw new ToolkitError('--import-existing-resources cannot be enabled with method=direct');
+      }
+      deploymentMethod = { method: 'direct' };
+      break;
+    case 'change-set':
+      deploymentMethod = {
+        method: 'change-set',
+        execute: true,
+        changeSetName: args.changeSetName,
+        importExistingResources: args.importExistingResources,
+      };
+      break;
+    case 'prepare-change-set':
+      deploymentMethod = {
+        method: 'change-set',
+        execute: false,
+        changeSetName: args.changeSetName,
+        importExistingResources: args.importExistingResources,
+      };
+      break;
+    case undefined:
+    default:
+      deploymentMethod = {
+        method: 'change-set',
+        execute: watch ? true : args.execute ?? true,
+        changeSetName: args.changeSetName,
+        importExistingResources: args.importExistingResources,
+      };
+      break;
+  }
+
+  const hotswapMode = determineHotswapMode(args.hotswap, args.hotswapFallback, watch);
+  const hotswapProperties = configuration.settings.get(['hotswap']) || {};
+  switch (hotswapMode) {
+    case HotswapMode.FALL_BACK:
+      return {
+        method: 'hotswap',
+        properties: hotswapProperties,
+        fallback: deploymentMethod,
+      };
+    case HotswapMode.HOTSWAP_ONLY:
+      return {
+        method: 'hotswap',
+        properties: hotswapProperties,
+      };
+    default:
+    case HotswapMode.FULL_DEPLOYMENT:
+      return deploymentMethod;
+  }
+}
+
 function determineHotswapMode(hotswap?: boolean, hotswapFallback?: boolean, watch?: boolean): HotswapMode {
   if (hotswap && hotswapFallback) {
     throw new ToolkitError('Can not supply both --hotswap and --hotswap-fallback at the same time');
diff --git a/packages/aws-cdk/test/cli/cdk-toolkit.test.ts b/packages/aws-cdk/test/cli/cdk-toolkit.test.ts
