(Opensearch): Allow importing an existing collection and index

[massi-ang]

Describe the feature

Allow to import existing collections and indexes to be used in the stack

Use Case

Customers might have already collections they want to use as a Bedrock Knowledge Base

Proposed Solution

Allow importing existing resources

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

[krokoko]

@massi-ang is this about adding a method like VectorCollection.fromExistingCollection() to VectorCollection so it can be used in KnowledgeBaseProps when instantiating a new KnowledgeBase ?

[LYTzeng]

+1 on this feature request. And yes @krokoko I think we need to have some way to import OSS collections/indexes that is created by aws-cdk-lib and transform it into VectorCollection type so that KnowledgeBase can consume it without creating new OSS collections and index. adding a method like VectorCollection.fromExistingCollection() to VectorCollection would be great.

[LYTzeng]

Since our project depends on this and we need to implement this w/o waiting for new releases coming out, is there a way that I can create a VectorCollection to be used in KnowledgeBaseProps without letting CDK to create an OSS collection in the current version?