使用 自動化區域間對等互連的設定 AWS Transit Gateway

透過取代 AWS 區域 和 儲存貯體名稱來更新下列提示：

- Active region: ACTIVE_REGION
- Passive region: PASSIVE_REGION
- S3_BUCKET : my-lambda-packages-bucket 
- STACK_NAME : transit-gateway-peering 
- All Lambda functions use two boto3 EC2 clients at module level (one per region), each with signature_version v4 and retries max_attempts=1 mode=standard.
- Print all API responses for CloudWatch logging.

將此儲存為 Markdown 檔案。

將此 Markdown 檔案新增至 Kiro 專案以取得內容。

在 Kiro 專案中，輸入下列提示：

Write a Python Lambda that creates a transit gateway peering attachment from active region  to passive region. Both of these regions will be read as environment variables of the Lambda function. Use two boto3 EC2 clients at the module level, one per Region. The handler should describe available transit gateways in both Regions. Then check if a peering attachment already exists on the active side by filtering describe_transit_gateway_attachments for resource-type "peering" and states: available, initiatingRequest, modifying, pendingAcceptance, pending, rejected, and rejecting. Only if zero results, create the peering attachment with tags for both Transit Gateway IDs, then wait 60 seconds (AWS needs this before the passive side can accept), then call accept_transit_gateway_peering_attachment on the passive client. Print all API responses.

儲存此檔案並命名為 peer-transit-gateway.py。

在 Kiro 專案中，輸入下列提示：

Using the shared context above, write a Python Lambda that polls peering attachment status. Describe available transit gateways in both regions, then call describe_transit_gateway_attachments on the active client filtered by the active Transit Gateway ID only (no resource-type filter). Return exactly `{'status': status}` where status is the State field from the first attachment. Do not return statusCode or body — the Step Function Choice state reads `$.Payload.status` and compares to "available".

儲存此檔案並命名為 get-transit-gateway-peering-status.py。

在 Kiro 專案中，輸入下列提示：

Using the shared context, write a Python Lambda that adds static routes to both regions' TGW route tables. Describe available transit gateways in both Regions, extract each transit gateway's AssociationDefaultRouteTableId. Discover routable VPCs by filtering describe_vpcs with tag `addtotransitgateway=true` in each region, collecting their CIDRs. Get the peering attachment ID from the active side by filtering on the active route table ID. For each passive CIDR, search the active route table using `route-search.exact-match` — only create the route if none found. For each active CIDR, search the passive route table using `route-search.supernet-of-match` (not exact-match — passive side may have supernet routes) — only create if none found. Both sides use the same peering attachment ID.

將此檔案儲存並命名為 modify-transit-gateway-routes.py。

輸入下列協同運作提示，以建立 CloudFormation 範本：

Write a CloudFormation JSON template that deploys: three Lambda functions (peer-transit-gateway with 600s timeout, get-transit-gateway-peering-status with 30s timeout, modify-transit-gateway-routes with 600s timeout), Lambda code from an S3 bucket parameter (no default value — user must supply the bucket name at deploy time), a Step Functions state machine, and CloudWatch log groups with 90-day retention. The state machine flow is:

1. Invoke peer-transit-gateway
2. Wait 20 seconds (attachment needs time after the Lambda's internal 20s sleep + acceptance)
3. Invoke get-transit-gateway-peering-status
4. Choice: if `$.Payload.status` equals "available" → go to step 5, otherwise loop back to step 2
5. Invoke modify-transit-gateway-routes → End

Use `Fn::Sub` with Lambda ARN references like `${PeerTransitGateways.Arn}` in the DefinitionString. The polling loop has no max retry — it loops until "available" (typically 3-5 minutes total).

儲存並命名檔案 transit-gateway-peering.json。

監控 Step Functions 工作流程是否成功完成。如需說明，請參閱 Step Functions 文件。

確認 Transit Gateway 連接對等狀態可用。如需說明，請參閱 Transit Gateway 文件。