Upgrading to CDK for Terraform Version 0.18

0.18 brings performance improvements to CDKTF along with improvements to the convert command.

Python performance improvements disable root-level provider imports

When using a Provider in python one could previously import the resource and data source namespaces on the root level. This is no longer possible and the namespaces must be imported through specifying the path in the import. The syntax was supported before as well, so you can change your code within 0.17.x and then upgrade to 0.18.x.

Before:

from constructs import Construct
from cdktf import App, TerraformStack
from imports.aws import provider, sns_topic, lambda_function, iam_role

class MyStack(TerraformStack):
    def __init__(self, scope: Construct, ns: str):
        super().__init__(scope, ns)

        provider.AwsProvider(self, 'Aws', region='eu-central-1')

        sns_topic.SnsTopic(self, 'Topic', display_name='my-first-sns-topic')
        role = iam_role.IamRole(self, 'Role', name='lambda-role',
                       assume_role_policy='{}')
        lambda_function.LambdaFunction(self, 'Lambda', function_name='my-first-lambda-function',
                       role=role.arn, handler='index.handler', runtime='python3.6')

app = App()
MyStack(app, "before-change")
app.synth()

After:

from constructs import Construct
from cdktf import App, TerraformStack
# This syntax was supported before as well
from imports.aws.provider import AwsProvider
from imports.aws.sns_topic import SnsTopic
from imports.aws.lambda_function import LambdaFunction
from imports.aws.iam_role import IamRole

class MyStack(TerraformStack):
    def __init__(self, scope: Construct, ns: str):
        super().__init__(scope, ns)

        AwsProvider(self, 'Aws', region='eu-central-1')

        SnsTopic(self, 'Topic', display_name='my-first-sns-topic')
        role = IamRole(self, 'Role', name='lambda-role',
                       assume_role_policy='{}')
        LambdaFunction(self, 'Lambda', function_name='my-first-lambda-function',
                       role=role.arn, handler='index.handler', runtime='python3.6')


app = App()
MyStack(app, "after-change")
app.synth()

Further support

If you encounter anything that is missing from this guide or not working as expected, please don't hesitate to file a bug so we can improve this guide. You can also post your question to HashiCorp Discuss using the terraform-cdk category.