Python->Using Construct Libraries->Extra Credit bug

[awsbenpeterson]

Describe the bug

When running cdk watch the hotswap operation for the ViewHitCounterRendered function created by this construct library does not successfully deploy. However, when I run cdk deploy without the --hotswap flag it is successful.

To be fair I'm not yet sure if this is a hotswap bug or a construct library bug, but in either situation it should be documented in the cdkworkshop unless this is a personal problem for just me.

Expected Behavior

I would expect the cdk deploy --hotswap command to yield the same result as cdk deploy but that is not the case.

Current Behavior

✨ hotswapping resources:
✨ Lambda Function 'cdk-workshop-ViewHitCounterRendered9C783E55-Nix6HHH67xmc'
✨ Lambda Function 'cdk-workshop-ViewHitCounterRendered9C783E55-Nix6HHH67xmc' hotswapped!

❌ cdk-workshop failed: InvalidParameterType: Expected params.Environment.Variables['TABLE_NAME'] to be a string
   at ParamValidator.fail (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:50:37)
   at ParamValidator.validateType (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:233:10)
   at ParamValidator.validateString (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:155:32)
   at ParamValidator.validateScalar (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:131:21)
   at ParamValidator.validateMember (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:95:21)
   at ParamValidator.validateMap (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:118:14)
   at ParamValidator.validateMember (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:93:21)
   at ParamValidator.validateStructure (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:76:14)
   at ParamValidator.validateMember (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:89:21)
   at ParamValidator.validateStructure (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-sdk/lib/param_validator.js:76:14) {
 code: 'InvalidParameterType',
 time: 2022-09-16T15:30:39.374Z
}

❌ Deployment failed: Error: Stack Deployments Failed: InvalidParameterType: Expected params.Environment.Variables['TABLE_NAME'] to be a string
   at deployStacks (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-cdk/lib/deploy.ts:61:11)
   at processTicksAndRejections (node:internal/process/task_queues:96:5)
   at CdkToolkit.deploy (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-cdk/lib/cdk-toolkit.ts:312:7)
   at CdkToolkit.invokeDeployFromWatch (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-cdk/lib/cdk-toolkit.ts:756:7)
   at deployAndWatch (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-cdk/lib/cdk-toolkit.ts:371:7)
   at FSWatcher.<anonymous> (/local/home/benpte/.nvm/versions/node/v16.17.0/lib/node_modules/aws-cdk/lib/cdk-toolkit.ts:400:9)

Reproduction Steps

This code snippet from the cdk_workshop_stack.py file as described in the workshop produces the error when running cdk deploy --hotswap and is successful when running cdk deploy

TableViewer(
            self, 'ViewHitCounter',
            title='Hello Hits',
            table=hello_with_counter.table,
            sort_by='-hits'
        )

Possible Solution

No response

Additional Information/Context

I actually found this running cdk watch and then realized it is a hotswap error.

CDK CLI Version

2.41.0 (build 6ad48a3)

Section

No response

Browser

No response

Language

Python

[awsbenpeterson]

aws/aws-cdk#20787

It looks like this is a feature request that has since been closed:
"Since Function's environment update is not considered hotswappable, user can never perform a hotswap deployment with this code."

[peterwoodworth]

We can make a note of this limitation in the hotswap section of the workshop, at the bottom of this page. Thanks for reporting!