feat(screenshot): Vercel preview screenshot → GitHub PR + Linear issue

cdk/package.json

@@ -17,28 +17,34 @@
     "@aws-cdk/aws-bedrock-agentcore-alpha": "2.238.0-alpha.0",
     "@aws-cdk/aws-bedrock-alpha": "2.238.0-alpha.0",
     "@aws-cdk/mixins-preview": "2.238.0-alpha.0",
+    "@aws-crypto/sha256-js": "^5.2.0",
     "@aws-sdk/client-bedrock-agentcore": "^3.1046.0",
     "@aws-sdk/client-bedrock-runtime": "^3.1021.0",
     "@aws-sdk/client-ecs": "^3.1021.0",
     "@aws-sdk/client-dynamodb": "^3.1021.0",
     "@aws-sdk/client-lambda": "^3.1021.0",
     "@aws-sdk/client-s3": "^3.1021.0",
     "@aws-sdk/client-secrets-manager": "^3.1021.0",
+    "@aws-sdk/credential-provider-node": "^3.972.29",
     "@aws-sdk/lib-dynamodb": "^3.1021.0",
     "@aws-sdk/s3-request-presigner": "^3.1021.0",
     "@aws/durable-execution-sdk-js": "^1.1.0",
     "@cedar-policy/cedar-wasm": "4.10.0",
+    "@smithy/protocol-http": "^5.3.12",
+    "@smithy/signature-v4": "^5.3.14",
     "aws-cdk-lib": "^2.238.0",
     "cdk-nag": "^2.37.55",
     "constructs": "^10.3.0",
-    "ulid": "^3.0.2"
+    "ulid": "^3.0.2",
+    "ws": "^8.18.0"
   },
   "devDependencies": {
     "@cdklabs/eslint-plugin": "^1.5.10",
     "@stylistic/eslint-plugin": "^2",
     "@types/aws-lambda": "^8.10.161",
     "@types/jest": "^30.0.0",
     "@types/node": "^20",
+    "@types/ws": "^8.5.13",
     "@typescript-eslint/eslint-plugin": "^8",
     "@typescript-eslint/parser": "^8",
     "aws-cdk": "^2",

cdk/src/constructs/github-screenshot-integration.ts

@@ -0,0 +1,267 @@
+/**
+ *  MIT No Attribution
+ *
+ *  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy of
+ *  the Software without restriction, including without limitation the rights to
+ *  use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ *  the Software, and to permit persons to whom the Software is furnished to do so.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+import * as path from 'path';
+import { ArnFormat, Duration, RemovalPolicy, Stack } from 'aws-cdk-lib';
+import * as apigw from 'aws-cdk-lib/aws-apigateway';
+import * as dynamodb from 'aws-cdk-lib/aws-dynamodb';
+import * as iam from 'aws-cdk-lib/aws-iam';
+import { Architecture, Runtime } from 'aws-cdk-lib/aws-lambda';
+import * as lambda from 'aws-cdk-lib/aws-lambda-nodejs';
+import * as secretsmanager from 'aws-cdk-lib/aws-secretsmanager';
+import { NagSuppressions } from 'cdk-nag';
+import { Construct } from 'constructs';
+import { ScreenshotBucket } from './screenshot-bucket';
+
+/**
+ * Properties for GitHubScreenshotIntegration construct.
+ */
+export interface GitHubScreenshotIntegrationProps {
+  /** The existing REST API to add the GitHub webhook route to. */
+  readonly api: apigw.RestApi;
+
+  /**
+   * Existing GitHub PAT secret. The processor reuses ABCA's main GitHub
+   * token to (a) look up which PR a deploy SHA belongs to via the
+   * Commits API, and (b) post the screenshot comment on that PR.
+   * No new GitHub credential is provisioned by this construct.
+   */
+  readonly githubTokenSecret: secretsmanager.ISecret;
+
+  /**
+   * Optional — when provided, the processor also tries to post the
+   * screenshot to a linked Linear issue. Resolved from the GitHub PR
+   * title/body via a Linear-identifier regex (e.g. `ABCA-42`), then
+   * looked up across all `status='active'` workspaces in the registry
+   * via Linear's `issueVcsBranchSearch` GraphQL.
+   */
+  readonly linearWorkspaceRegistryTable?: dynamodb.ITable;
+
+  /**
+   * Removal policy for the dedup table + screenshot bucket. Defaults
+   * to DESTROY so dev stacks don't accumulate orphans on `cdk destroy`.
+   */
+  readonly removalPolicy?: RemovalPolicy;
+
+  /**
+   * Override for the deploy environment we screenshot. Defaults to
+   * `Preview` (Vercel's label for per-PR deploys). Set this when
+   * targeting a different deploy backend.
+   * @default 'Preview'
+   */
+  readonly screenshotTargetEnvironment?: string;
+}
+
+/**
+ * CDK construct that adds the GitHub-deployment-status → screenshot →
+ * PR-comment pipeline.
+ *
+ * Topology mirrors `LinearIntegration`:
+ *   - Receiver Lambda (HMAC-verifies, dedups, async-invokes processor)
+ *   - Async processor Lambda (drives AgentCore Browser, uploads PNG,
+ *     posts the PR comment)
+ *   - Dedup DynamoDB table (1h TTL — covers GitHub's 5-attempt retry
+ *     window with slack)
+ *   - Webhook signing-secret (Secrets Manager placeholder; populated
+ *     manually when the operator pastes GitHub's value into the secret)
+ *   - Public-read screenshot S3 bucket
+ *   - API Gateway route `POST /v1/github/webhook`
+ *
+ * Inbound-only adapter — there's no outbound polling or stream
+ * consumer, just the webhook → screenshot → comment fan-out.
+ */
+export class GitHubScreenshotIntegration extends Construct {
+  /** Public-read bucket hosting the screenshot PNGs. */
+  public readonly screenshotBucket: ScreenshotBucket;
+
+  /**
+   * GitHub webhook signing secret — placeholder. The operator pastes
+   * GitHub's signing-secret value here after configuring the webhook
+   * in the demo repo's settings; the secret is otherwise empty.
+   */
+  public readonly webhookSecret: secretsmanager.Secret;
+
+  /** Webhook dedup table (composite key = `repo#deployment_id#status_id`). */
+  public readonly webhookDedupTable: dynamodb.Table;
+
+  /** Webhook receiver Lambda (HMAC verifier + dispatcher). */
+  public readonly webhookFn: lambda.NodejsFunction;
+
+  /** Async processor Lambda (browser + S3 + PR comment). */
+  public readonly webhookProcessorFn: lambda.NodejsFunction;
+
+  constructor(scope: Construct, id: string, props: GitHubScreenshotIntegrationProps) {
+    super(scope, id);
+
+    const removalPolicy = props.removalPolicy ?? RemovalPolicy.DESTROY;
+
+    // --- Screenshot bucket (public-read on `screenshots/*`) ---
+    this.screenshotBucket = new ScreenshotBucket(this, 'ScreenshotBucket', {
+      removalPolicy,
+    });
+
+    // --- Webhook signing secret (operator-populated placeholder) ---
+    this.webhookSecret = new secretsmanager.Secret(this, 'WebhookSecret', {
+      description: 'GitHub deployment-status webhook signing secret — populate manually after configuring the GitHub webhook',
+      removalPolicy,
+    });
+
+    // --- Dedup table ---
+    this.webhookDedupTable = new dynamodb.Table(this, 'WebhookDedupTable', {
+      partitionKey: { name: 'dedup_key', type: dynamodb.AttributeType.STRING },
+      billingMode: dynamodb.BillingMode.PAY_PER_REQUEST,
+      timeToLiveAttribute: 'ttl',
+      pointInTimeRecoverySpecification: { pointInTimeRecoveryEnabled: true },
+      removalPolicy,
+    });
+
+    const handlersDir = path.join(__dirname, '..', 'handlers');
+    const commonBundling: lambda.BundlingOptions = {
+      externalModules: ['@aws-sdk/*'],
+    };
+
+    // --- Async processor (browser + S3 + comment) ---
+    // Timeout budget: 60s screenshot + 5s navigate slack + 30s slack for
+    // the GitHub PR-lookup + comment + S3 PUT + JSON encode = 95s. Round
+    // to 120 for headroom on cold-start CDP handshake.
+    this.webhookProcessorFn = new lambda.NodejsFunction(this, 'WebhookProcessorFn', {
+      entry: path.join(handlersDir, 'github-webhook-processor.ts'),
+      handler: 'handler',
+      runtime: Runtime.NODEJS_24_X,
+      architecture: Architecture.ARM_64,
+      timeout: Duration.seconds(120),
+      memorySize: 512,
+      environment: {
+        SCREENSHOT_BUCKET_NAME: this.screenshotBucket.bucket.bucketName,
+        SCREENSHOT_PUBLIC_HOST: this.screenshotBucket.distribution.domainName,
+        GITHUB_TOKEN_SECRET_ARN: props.githubTokenSecret.secretArn,
+        ...(props.linearWorkspaceRegistryTable && {
+          LINEAR_WORKSPACE_REGISTRY_TABLE_NAME: props.linearWorkspaceRegistryTable.tableName,
+        }),
+      },
+      bundling: commonBundling,
+    });
+
+    this.screenshotBucket.bucket.grantPut(this.webhookProcessorFn);
+    props.githubTokenSecret.grantRead(this.webhookProcessorFn);
+
+    // Optional Linear feedback path. Wired only when a registry table
+    // is provided. The processor scans the registry for active
+    // workspaces, then per-workspace looks up the OAuth token from
+    // Secrets Manager (`bgagent-linear-oauth-*` prefix, written by
+    // `bgagent linear setup`).
+    if (props.linearWorkspaceRegistryTable) {
+      props.linearWorkspaceRegistryTable.grantReadData(this.webhookProcessorFn);
+      this.webhookProcessorFn.addToRolePolicy(new iam.PolicyStatement({
+        actions: ['secretsmanager:GetSecretValue', 'secretsmanager:PutSecretValue'],
+        resources: [
+          Stack.of(this).formatArn({
+            service: 'secretsmanager',
+            resource: 'secret',
+            arnFormat: ArnFormat.COLON_RESOURCE_NAME,
+            resourceName: 'bgagent-linear-oauth-*',
+          }),
+        ],
+      }));
+    }
+
+    // AgentCore Browser session lifecycle + automation-stream connect.
+    // The data-plane API doesn't support per-resource ARNs (sessions
+    // are ephemeral), so wildcards are required — annotated with a
+    // cdk-nag suppression below. The wildcard set covers
+    // `ConnectBrowserAutomationStream` (the SigV4-presigned WSS dial)
+    // which lives under the same prefix but isn't visible in the
+    // public CLI command list.
+    this.webhookProcessorFn.addToRolePolicy(new iam.PolicyStatement({
+      actions: ['bedrock-agentcore:*'],
+      resources: ['*'],
+    }));
+
+    // --- Webhook receiver (verify, dedup, dispatch) ---
+    this.webhookFn = new lambda.NodejsFunction(this, 'WebhookFn', {
+      entry: path.join(handlersDir, 'github-webhook.ts'),
+      handler: 'handler',
+      runtime: Runtime.NODEJS_24_X,
+      architecture: Architecture.ARM_64,
+      timeout: Duration.seconds(10),
+      environment: {
+        GITHUB_WEBHOOK_SECRET_ARN: this.webhookSecret.secretArn,
+        GITHUB_WEBHOOK_DEDUP_TABLE_NAME: this.webhookDedupTable.tableName,
+        GITHUB_WEBHOOK_PROCESSOR_FUNCTION_NAME: this.webhookProcessorFn.functionName,
+        ...(props.screenshotTargetEnvironment && {
+          SCREENSHOT_TARGET_ENVIRONMENT: props.screenshotTargetEnvironment,
+        }),
+      },
+      bundling: commonBundling,
+    });
+
+    this.webhookSecret.grantRead(this.webhookFn);
+    this.webhookDedupTable.grantReadWriteData(this.webhookFn);
+    this.webhookProcessorFn.grantInvoke(this.webhookFn);
+
+    // --- API Gateway route ---
+    const githubResource = props.api.root.addResource('github');
+    const webhookResource = githubResource.addResource('webhook');
+    const webhookMethod = webhookResource.addMethod(
+      'POST',
+      new apigw.LambdaIntegration(this.webhookFn),
+      { authorizationType: apigw.AuthorizationType.NONE },
+    );
+
+    NagSuppressions.addResourceSuppressions(webhookMethod, [
+      {
+        id: 'AwsSolutions-APIG4',
+        reason: 'GitHub webhook endpoint authenticates via X-Hub-Signature-256 HMAC, not Cognito — required by GitHub webhook protocol.',
+      },
+      {
+        id: 'AwsSolutions-COG4',
+        reason: 'GitHub webhook endpoint authenticates via X-Hub-Signature-256 HMAC, not Cognito — required by GitHub webhook protocol.',
+      },
+    ]);
+
+    NagSuppressions.addResourceSuppressions(this.webhookFn, [
+      {
+        id: 'AwsSolutions-IAM4',
+        reason: 'AWSLambdaBasicExecutionRole is the standard managed policy for Lambda CloudWatch Logs writes.',
+      },
+      {
+        id: 'AwsSolutions-IAM5',
+        reason: 'DynamoDB grants from CDK helpers expand to table-arn/index/* wildcards; receiver only writes to the dedup table.',
+      },
+    ], true);
+
+    NagSuppressions.addResourceSuppressions(this.webhookProcessorFn, [
+      {
+        id: 'AwsSolutions-IAM4',
+        reason: 'AWSLambdaBasicExecutionRole is the standard managed policy for Lambda CloudWatch Logs writes.',
+      },
+      {
+        id: 'AwsSolutions-IAM5',
+        reason: 'AgentCore Browser sessions are ephemeral and have no per-resource ARN; the data-plane API requires wildcards. S3 PutObject uses CDK grant helpers that expand to bucket/* wildcards.',
+      },
+    ], true);
+
+    NagSuppressions.addResourceSuppressions(this.webhookSecret, [
+      {
+        id: 'AwsSolutions-SMG4',
+        reason: 'GitHub webhook signing-secret rotation is owned by GitHub (operator regenerates on the GitHub side and pastes the new value here). No automated rotation Lambda needed.',
+      },
+    ]);
+  }
+}