Docker Image URI CfnOutput Not Working

[Wildhammer]

Description of the bug:

I want to create a docker image using CDK DockerImageAsset and pass the image URI to the cronjob tutorial example as an environment variable. My intention is to ultimately use the image URI for creating my service pods.

Reproduction Steps:

Just modify the example code at cdk8s-awscdk-resolver and add cdk code for building an image. Then use the CfnOutput for imageUri same way as bucket name is passed in the example:

import * as aws from 'aws-cdk-lib';
import * as k8s from 'cdk8s';
import * as kplus from 'cdk8s-plus-27';

import { AwsCdkResolver } from '@cdk8s/awscdk-resolver';
import { DockerImageAsset } from 'aws-cdk-lib/aws-ecr-assets';
import { CfnOutput } from 'aws-cdk-lib';

const awsApp = new aws.App();
const stack = new aws.Stack(awsApp, 'aws');

const k8sApp = new k8s.App({ resolvers: [new AwsCdkResolver()] });
const manifest = new k8s.Chart(k8sApp, 'Manifest');

const bucket = new aws.aws_s3.Bucket(stack, 'Bucket');
const bucketName = new aws.CfnOutput(stack, 'BucketName', {
  value: bucket.bucketName,
});

const image = new DockerImageAsset(stack, 'Image', {
  directory: 'app',
});
const imageUri = new CfnOutput(stack, 'imageUri', { value: image.imageUri });

new kplus.CronJob(manifest, 'CronJob', {
  schedule: k8s.Cron.daily(),
  containers: [{
    image: 'job',
    envVariables: {
      // directly passing the value of the `CfnOutput` containing 
      // the deploy time bucket name
      BUCKET_NAME: kplus.EnvValue.fromValue(bucketName.value),
      IMAGE_NAME: kplus.EnvValue.fromValue(imageUri.value)
    }
 }]
});

awsApp.synth();
k8sApp.synth();

Error Log:

Error: Failed serializing construct at path 'Manifest/CronJob/Resource' with name 'manifest-cronjob-c86481e8': Error: Unable to find output defined for ${Token[TOKEN.28]} (Inspected stacks: )

Environment:

• ^0.0.57:
• MacOS:

Other:

I tried creating an iam role and passing the role name as env variable. That seemed to work fine.

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This is 🐛 Bug Report

[jfalkenstein]

I'm encountering this too. I did a little debugging and it appears as if the issue is the tokens for the docker image uri isn't a "Reference" like most other CfnOutput values are. Instead, it's a FnSub:

In this case, the evaluation of IsReference() resolves to false and the output isn't resolved.

[jfalkenstein]

I think a short-term hacky solution to this would be save the image uri to an SSM parameter and then set the CfnOutput value to the SSM Parameter's .value attribute. Thus, the output wouldn't be a FnSub but instead would be just a normal reference.