fix: add --import-existing-resources to CDK deploy in integration-suite

[jchrostek-dd]

What changed and why

Added --import-existing-resources flag to the npx cdk deploy command in the integration-suite CI job (.gitlab/templates/pipeline.yaml.tpl).

Root cause: When a pipeline fails mid-deploy, some AWS resources (specifically the dotnet Lambda log group /aws/lambda/integ-{IDENTIFIER}-{TEST_SUITE}-dotnet-lambda) are created in AWS but the CloudFormation stack is left in ROLLBACK_COMPLETE state. On a pipeline retry for the same commit (same IDENTIFIER = CI_COMMIT_SHORT_SHA), CDK attempts to create the already-existing log group and fails with:

ToolkitError: ChangeSet 'cdk-deploy-change-set' on stack 'integ-{IDENTIFIER}-{TEST_SUITE}' failed early validation:
  - Resource of type 'AWS::Logs::LogGroup' with identifier '/aws/lambda/integ-{IDENTIFIER}-{TEST_SUITE}-dotnet-lambda' already exists.

The --import-existing-resources flag tells CDK to import any already-existing resources into the stack instead of failing validation, which is the standard CDK solution for this exact scenario.

Jira

SVLS-8825

[Copilot]

Pull request overview

This PR adds the --import-existing-resources flag to the CDK deploy command in the integration-suite CI job to handle pipeline retry scenarios. When a pipeline fails mid-deploy, AWS resources (particularly Lambda log groups) can be created in AWS, but the CloudFormation stack remains in ROLLBACK_COMPLETE state. On retry, CDK would fail trying to create already-existing resources. The flag tells CDK to import existing resources instead of failing validation, which is the standard CDK solution for this scenario.

Changes:

• Added --import-existing-resources flag to the npx cdk deploy command in the integration-suite job