Amazon Bedrock Workshop - [Bug] 02_qa_w_rag_claude_opensearch.ipynb hardcoded to use us-east-1

[jicowan]

Describe the bug
The following code in 02_qa_w_rag_claude_opensearch.ipynb will throw an error if the AWS_DEFAULT_REGION is not set. Update to retrieve the region dynamically, e.g. boto3.session.Session.region_name. Do not hard code the region.

from opensearchpy import OpenSearch, RequestsHttpConnection, AWSV4SignerAuth
from langchain.vectorstores import OpenSearchVectorSearch

service = 'aoss'
credentials = boto3.Session().get_credentials()
auth = AWSV4SignerAuth(credentials, os.environ.get("AWS_DEFAULT_REGION", 'us-east-1'), service)

The following line in 02_qa_w_rag_claude_opensearch.ipynb will also throw an error if the REGION is not set:

host = collection['createCollectionDetail']['id'] + '.' + os.environ.get("AWS_DEFAULT_REGION", None) + '.aoss.amazonaws.com:443'

None is not an appropriate value if the variable is not set.

[w601sxs]

I agree, can you do a quick PR @jicowan ? Thank you for catching this and improving our examples