feat(mixins-preview): add `recordFields` and `outputFormat` to Vended Logs Mixin by ShadowCat567 · Pull Request #37042 · aws/aws-cdk

ShadowCat567 · 2026-02-20T19:07:37Z

Reason for this change

We want to support passing in outputFormat and recordFields to the VendedLogsMixin.

Description of changes

Added support for outputFormat and recordFields in the VendedLogsMixin. There are some important design decisions that happened here:

toDestination() and toXRay() do not support outputFormat. This is because outputFormat is something that is set in the destination and toDestination() does not actually have direct access to the destination resource that was passed into it. If the user wants to set an outputFormat in their destination resource, we assume they already did so. toXRay does not support outputFormat because the XRay destination does not support setting an outputFormat.
When we pass recordFields vs when we rely on default implementation. The default implementation of recordFields (RecordFields: undefined in the delivery) includes all possible recordFields for a delivery. I did not want to mess with this default implementation and have something that may be unexpected happen if a delivery has both optional and mandatory fields and the user does not pass in any optional fields. So when a delivery only has mandatory fields or it has mandatory fields but can take optional ones, in the case no optional fields are passed in, we use the default implementation. When optional fields are present we set RecordFields to the optional fields or if a delivery has mandatory fields we set RecordFields to the optional fields we got + the delivery's mandatory fields.

When we don't get an outputFormat for S3, Firehose, and Cloudwatch destinations, we also fall back to whatever the default is by providing undefined.
I have done my own manual testing to verify that providing undefined to OutputFormat and RecordFields works as I have described here.

Describe any new or updated permissions being added

N/A

Description of how you validated changes

Update integration and unit test coverage

Checklist

My code adheres to the CONTRIBUTING GUIDE and DESIGN GUIDELINES

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

github-actions · 2026-02-20T19:54:13Z

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
Please try merge from main to avoid findings unrelated to the PR.

	Tests	Passed ✅	Skipped	Failed
Security Guardian Results	24 ran	24 passed

Test	Result
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github-actions · 2026-02-20T19:54:15Z

⚠️ Experimental Feature: This security report is currently in experimental phase. Results may include false positives and the rules are being actively refined.
Please try merge from main to avoid findings unrelated to the PR.

	Tests	Passed ✅	Skipped	Failed
Security Guardian Results with resolved templates	24 ran	24 passed

Test	Result
No test annotations available

View Security Guardian Results with resolved templates

aws-cdk-automation

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mrgrain · 2026-02-24T15:00:02Z

packages/@aws-cdk/mixins-preview/test/services/aws-logs/integ.delivery-mixin.ts

@@ -24,7 +24,10 @@ const logGroup = new logs.LogGroup(stack, 'DeliveryLogGroup', {
 });

 // Setup delivery
-eventBus.with(CfnEventBusLogsMixin.ERROR_LOGS.toLogGroup(logGroup));
+eventBus.with(CfnEventBusLogsMixin.ERROR_LOGS.toLogGroup(logGroup, {
+  outputFormat: CfnEventBusErrorLogsLogGroupOutputFormat.JSON,


Allegedly you can pass strings into a string enum (like this), however typescript does not like it - gives me an error

mrgrain · 2026-02-24T15:02:16Z

packages/@aws-cdk/mixins-preview/lib/services/aws-logs/logs-delivery.ts

 }

 /**
 * Props for S3LogsDelivery
 */
-export interface S3LogsDeliveryProps {
+export interface IS3LogsDeliveryProps extends IDeliveryProps {


Props shouldn't be a behavioural interface.

I don't think I understand, how should this be restructured? Since S3 has some unique things (mostly encryptionKey) that I think should be a part of props

mrgrain · 2026-02-24T15:03:04Z

packages/@aws-cdk/mixins-preview/lib/services/aws-logs/logs-delivery.ts

+export interface IRecordFieldDeliveryProps {
  /**
-   * V1
+   * Optional RecordFields that are not required for log delivery
+   * These may or may not be passed in by the user
+   *
+   * @defualt - no optional fields
   */
-  V1 = 'V1',
+  readonly optionalFields?: string[];
  /**
-   * V2
+   * Required RecordFields are mandatory to be included in a log delivery
+   *
+   * @default - no mandatory fields
   */
-  V2 = 'V2',
+  readonly mandatoryFields?: string[];
 }


The distinction here between optionalFields and mandatoryFields seems unnecessary.

we do need both in here, I think these were just the wrong names. optionalFields is now providedFields, it represents the fields the user provided us. mandatoryFields remains pretty much the same, it's an array of a delivery's mandatory fields.

mrgrain · 2026-02-24T15:05:21Z

packages/@aws-cdk/mixins-preview/test/codegen/__snapshots__/logs-delivery.test.ts.snap

+        optionalFields: props?.additionalFields,
+        mandatoryFields: ["resource-id","body"]


we can combine these in the code gen

I think this is a little confusing, since optionalFields/additionalFields is public facing, while mandatoryFields is not. Yes, we can add the mandatoryFields to the additionalFields enum type, but I think we should still have the mandatoryFields passed into the LogDelivery class for the logic surrounding what we set recordFields to in there.

mrgrain · 2026-02-24T15:06:57Z

packages/@aws-cdk/mixins-preview/test/codegen/__snapshots__/logs-delivery.test.ts.snap

+  readonly additionalFields?: Array<CfnThingApplicationLogsAdditionalFields>;
+}
+
+export enum CfnThingApplicationLogsLogGroupOutputFormat {


okay i see how this is getting ridiculous. maybe we do a single output format for everything and do docs and runtime validation?

what do you mean? Not all destinations share the same outputFormats?

mrgrain · 2026-02-24T15:07:44Z

packages/@aws-cdk/mixins-preview/test/codegen/__snapshots__/logs-delivery.test.ts.snap

@@ -157,5 +201,149 @@ export class CfnThingLogsMixin extends core.Mixin implements core.IMixin {
    const sourceArn = service.CfnThing.arnForThing(resource);
    this.logDelivery.bind(resource, this.logType, sourceArn);
  }
+}
+
+export enum CfnThingApplicationLogsAdditionalFields {


Hmm. I wonder if the enum should have all fields. We can do the adding of mandatory fields and deduplication in code.

mrgrain

some ideas.

aws-amplify-bot added 2 commits February 20, 2026 14:05

recrodfields and outputformats - no tests

a11b813

updating typewriter

2ceaeaf

github-actions bot added p2 valued-contributor [Pilot] contributed between 6-12 PRs to the CDK labels Feb 20, 2026

mergify bot added the contribution/core This is a PR that came from AWS. label Feb 20, 2026

update integ tests, add unit tests

a568343

ShadowCat567 marked this pull request as ready for review February 20, 2026 20:02

ShadowCat567 changed the title ~~chore(mixins-preview): add recordFields and outputFormat to Vended Logs Mixin~~ feat(mixins-preview): add recordFields and outputFormat to Vended Logs Mixin Feb 20, 2026

aws-cdk-automation added the pr/needs-maintainer-review This PR needs a review from a Core Team Member label Feb 23, 2026

aws-cdk-automation requested changes Feb 23, 2026

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aws-cdk-automation removed the pr/needs-maintainer-review This PR needs a review from a Core Team Member label Feb 23, 2026

mrgrain reviewed Feb 24, 2026

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mrgrain requested changes Feb 24, 2026

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		optionalFields: props?.additionalFields,
		mandatoryFields: ["resource-id","body"]

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ShadowCat567 commented Feb 20, 2026 •

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mrgrain Feb 24, 2026 •

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ShadowCat567 Feb 24, 2026 •

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