[2023-04-30 20:48:50,640] ERROR in app: Exception on /api/message_groups [GET]
Traceback (most recent call last):
  ...
  File "/backend-flask/app.py", line 209, in data_message_groups
    model = MessageGroup.run(cognito_user_id=cognito_user_id)
  File "/backend-flask/services/message_group.py", line 23, in run
    data = ddb.list_message_groups(dynamodb, current_user_uuid)
  File "/backend-flask/lib/ddb.py", line 35, in list_message_groups
    response = client.query(**query_params)
    ...
    raise error_class(parsed_response, operation_name)
botocore.errorfactory.ResourceNotFoundException: 
    An error occurred (ResourceNotFoundException) when calling the Query operation: 
    Cannot do operations on a non-existent table

Error

• Cannot do operations on a non-existent table

Possibiliities

✅ 1. Chekc if DynamoDB container is running.

•   $ docker ps
  
    b699b1fab5eb   amazon/dynamodb-local:latest  "java -jar DynamoDBL…"  \
        23 minutes ago   Up 23 minutes \
        0.0.0.0:8000->8000/tcp, :::8000->8000/tcp dynamodb-local
  

✅ 2. Check env variables used to create DynamoDB client.

• Depending on your dev environment, check local machine, gitpod variable store and alike.

    class ddb:
      def client():
        endpoint_url = os.getenv("AWS_ENDPOINT_URL")  <---------
        if endpoint_url:
          attrs = { 'endpoint_url': endpoint_url }
        else:
          attrs = {}
        dynamodb = boto3.client('dynamodb',**attrs)
        return dynamodb
  

✅ 3. Check if the env variables are correctly imported into the docker container.

• You can either attach shell to the container, or run this comment on terminal: docker exec -it <CONTAINER_ID> /bin/bash

    # Inside the running flask container:
    root@a351ce655a9b:/backend-flask# echo $AWS_ENDPOINT_URL
    http://dynamodb-local:8000
  

✅ 4. Check if you have correctly seeded some seed data and they are actually on the DB.

Solution

✅ In my case, DynamoDB client was NOT running.